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Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Little change to Isaac, but storm poses a serious storm surge threat

By: Dr. Jeff Masters, 3:25 PM GMT on August 27, 2012

Tropical Storm Isaac has changed little in strength or organization this morning, as the storm heads northwest at 14 mph towards the Central Gulf Coast. There are two hurricane hunter aircraft in the storm, and Isaac's central pressure held steady at 989 mb at the 8:30 am and 9:15 am center fixes. Top surface winds remain near 65 mph. Infrared and visible satellite loops show that Isaac is a very large storm, but isn't very symmetric. Heavy thunderstorm activity is lacking on the southeast side, where 10 knots of wind shear is driving dry air into the circulation. The center is surrounded by a ring of echoes now, which was not the case on Sunday. However, the echoes are weak. The 8:30 am center report from the Hurricane Hunters reported about half of a ragged eyewall, but the 9:15 am report did not mention any evidence of an eyewall. Isaac will have to form an eyewall in order to intensify significantly.


Figure 1. Morning satellite image of Isaac. Note the lack of heavy thunderstorm activity on the storm's southeast side, where dry air and wind shear are combining to interfere with development.

Isaac's rains
Isaac's heaviest rains have fallen along a swath from the east coast of Florida near West Palm Beach to the center of the state, just south of Orlando. West Palm Beach received 7.57" of rain from Isaac as of 10 am EDT this morning. A trained spotter in Western Boynton Beach reported 10" of rain from midnight to midnight Sunday. Heavy rains from Isaac are lingering over Cuba but have ended in Haiti and the Dominican Republic; flash floods in Haiti from Isaac's torrential rains killed at least nineteen, and two died in the Dominican Republic.


Figure 2. Radar-estimated rainfall from Melbourne, Florida radar shows that Isaac has dumped a wide swath of 3+ inches of rain (orange colors) across the state.

Latest model runs for Isaac
The latest set of 0Z and 06Z (8 pm and 2 am EDT) model runs are fairly unified taking Isaac ashore near Southeast Louisiana late Tuesday night or early Wednesday morning, but continue to show major differences in what happens after that. It is still uncertain if a trough of low pressure passing to the north of Isaac will be able to turn the storm due north, as the ECMWF model is predicting, or bypass the storm, allowing a more west-northwest motion into western Louisiana, like the GFS model is predicting. In either case, Isaac is likely to slow down as it approaches the coast, which will increase the damage potential fro m its wind, storm surge, and rains. The latest 8-day precipitation forecast from the GFS model calls for 10 - 20 inches of rain over much of Louisiana. The ECMWF model predicts that these heavy rains will fall more over Mississippi. It appears likely that Arkansas will see some heavy rains from Isaac late in the week, which would help put a dent in the exceptional drought conditions there.


Figure 3. Predicted precipitation for the 8-day period from 2 am Monday August 27 to 2 am Tuesday September 4, from the 2 am EDT August 27 run of the GFS model. This model is predicting a wide swath of 5 - 10 inches of rain (orange colors) will affect portions of Louisiana. Additional very heavy rains are predicted for the Midwest, as moisture from Isaac interacts with a cold front. Image credit: NOAA/NCEP.

Intensity forecast for Isaac
Isaac is currently crossing over a relatively cool eddy of water, which will keep intensification slow today. By tonight, the total heat content of the waters increases, which should aid intensification. Low wind shear of 10 knots or less is likely until landfall. An analysis of upper level winds from the University of Wisconsin CIMSS shows that upper-level outflow to the north is not as strong as yesterday, which should also slow intensification today. The models forecast the upper-level outflow should improve by Tuesday. A storm this large will have trouble undergoing rapid intensification, and Isaac's most likely intensity at landfall will be as a Category 1 hurricane, which is what most of the intensity models are forecasting.


Figure 4. Track of Hurricane Gustav of 2008, which followed a path very similar to that of Isaac's predicted path.

Storm surge forecast for Isaac
Storm surge is the primary damage threat from Isaac. Isaac is a huge storm, with tropical storm-force winds that extend out 205 miles from the center. For comparison, Hurricane Katrina at landfall had tropical storm-force winds that extended out 230 miles from its center. Isaac's large size will enable it to set a large area of the ocean into motion, which will generate a large storm surge once the storm approaches land on the Gulf Coast. Water levels at Shell Beach, Louisiana, just east of New Orleans, were already elevated by 1' this morning. Conversely, water levels have fallen by 2' this morning at St. Petersburg, Florida, where strong offshore winds due to Isaac's counter-clockwise circulation have carried water away from the coast. The latest 6:30 am EDT Integrated Kinetic Energy analysis from NOAA's Hurricane Research Division put the destructive potential of Isaac's winds near 0.6 on a scale of 0 to 6, but the destructive potential of Isaacs's storm surge was 2.1 on a scale of 0 to 6. I expect this destructive potential will rise above 3 by time Isaac makes landfall, making Isaac's storm surge similar to that generated by Category 2 Hurricane Gustav of 2008, which followed a path very similar to Isaac's predicted path. Gustav brought a storm surge characteristic of a Category 1 hurricane to New Orleans: 9.5' to Lake Borgne on the east side of the city. A higher Category 2-scale surge occurred along the south-central coast of Louisiana, and was 12.5' high in Black Bay, forty miles southeast of New Orleans. Recent model runs indicate Isaac may slow down to a forward speed under 5 mph on Tuesday evening and Wednesday morning, close to the coast. If Isaac is just offshore at this time, the coasts of Southeast Louisiana, Mississippi, Alabama, and the Florida Panhandle will be exposed to a large storm surge with battering waves for two high tide cycles. This sort of extending pounding will be capable of delivering more damage than the storm surge of Hurricane Gustav of 2008.

The affect of storm size and angle of approach on storm surge
A 2008 paper by Irish et al., The influence of storm size on hurricane surge, found that large storms like Isaac are capable to delivering a 30% larger storm surge to the coast than a smaller storm with the same maximum wind speeds. The angle with which the storm hit the coast is important, too--a storm moving due north or slightly east of north will deliver a storm surge about 10% greater than a storm moving NNW or NW. Consult our Storm Surge pages for detailed information on what the risk is for the coast. I expect that Isaac's storm surge will be about 30% higher than the typical surge one would expect based on the maximum wind speeds.

Isaac's storm surge will provide the first test of the newly-completed New Orleans levee system upgrade. In the wake of the disastrous storm surge flooding from Hurricane Katrina in 2005, Congress appropriated $14.5 billion to upgrade the New Orleans levee system to withstand a Category 3 hurricane storm surge. Katrina was a Category 3 storm at landfall, but the storm passed far enough to the east of the city that its storm surge was characteristic of a Category 1 - 2 storm at the places where the city's flood walls and levees failed. The new flood defenses were only partially completed in time for the arrival of Hurricane Gustav in 2008, which hit Central Louisiana as a Category 2 storm. Gustav brought a storm surge characteristic of a Category 1 hurricane to New Orleans: 9.5' to Lake Borgne on the east side of the city. Since that time, the imposing 2-mile long IHNC Flood Barrier has been completed to block off the funnel-shaped pair of canals on the east side of the city. I expect New Orleans' new flood defenses will be able to hold back Isaac's surge, but areas outside the levees are at risk of heavy storm surge damage.


Figure 5. A portion of New Orleans' new $14.5 billion dollar flood defenses, as taken from an Army Corps of Engineers map.

New Orleans flood defense info
Army Corps of Engineers map of the new flood defenses
Army Corps of Engineers video showing the flood defenses
New York Times article, Vast Defenses Now Shielding New Orleans

Invest 97L off the coast of Africa
A tropical wave (Invest 97L) is located in the Middle Atlantic, about 1050 miles west-northwest of the Cape Verde Islands. The storm has a modest amount of spin and heavy thunderstorms, and is under moderate wind shear. In their 8 am EDT Tropical Weather Outlook, NHC gave 97L a 30% chance of developing by Wednesday morning. None of the reliable models foresee that 97L will be a threat to the Lesser Antilles Islands, and high wind shear should begin to tear the disturbance apart on Tuesday.

Another tropical wave that moved off the coast of Africa on Sunday is located just south of the Cape Verde Islands. This disturbance is moving west at 10 - 15 mph, and could arrive in the Lesser Antilles around September 2. Several models develop the disturbance into a tropical depression late this week, and NHC is giving the disturbance a 10% chance of becoming a tropical depression by Wednesday morning.

Angela Fritz will have a new post here by 6 pm EDT. I'm in Atlanta to help out The Weather Channel with their on-air hurricane coverage, and will doing a few 3-minute tropical updates at 30 minutes past the hour between 2:30 - 7:30 pm EDT today.

Jeff Masters
Tropical Storm Isaac
Tropical Storm Isaac
View from the north side of the Sunshine Skyway Bridge.
our street at noon today
our street at noon today
Aug 26, 2012: Isaac floods our street really bad. Now nearly 11

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

1501. flcanes
Quoting TropicalAnalystwx13:
TROPICAL DEPRESSION NINE-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092012
200 PM PDT MON AUG 27 2012

SATELLITE IMAGES SHOW THAT THE LOW PRESSURE SYSTEM LOCATED A FEW
HUNDRED MILES SOUTH-SOUTHWEST OF MANZANILLO MEXICO HAS DEVELOPED
ORGANIZED DEEP CONVECTION DURING THE LAST SEVERAL HOURS. IN
ADDITION...RECENT MICROWAVE DATA INDICATE THAT THE LOW-LEVEL CENTER
HAS BECOME WELL DEFINED. THEREFORE...THE LOW IS NOW CLASSIFIED AS A
TROPICAL DEPRESSION...THE NINTH OF THE EAST PACIFIC SEASON. THE
INITIAL INTENSITY IS 30 KT...THOUGH SOME ESTIMATES SUGGEST IT COULD
BE A LITTLE STRONGER. THE DEPRESSION IS FORECAST TO GAIN STRENGTH
DURING THE NEXT 3 TO 4 DAYS AS ENVIRONMENTAL CONDITIONS ARE
EXPECTED TO BE FAVORABLE. AFTER DAY 4...THE CYCLONE IS EXPECTED TO
MOVE OVER COOLER WATERS...AND THAT SHOULD END THE STRENGTHENING
TREND. THE OFFICIAL FORECAST IS IN THE MIDDLE OF THE INTENSITY
GUIDANCE ENVELOPE...IN CLOSEST AGREEMENT WITH LGEM.

THE DEPRESSION IS MOVING WEST-NORTHWESTWARD AT ABOUT 11 KT ON THE
SOUTH SIDE OF A MID-LEVEL RIDGE CENTERED OVER THE SOUTHWESTERN U.S.
THIS GENERAL MOTION SHOULD CONTINUE FOR ANOTHER DAY OR TWO AS THE
RIDGE REMAINS THE PRIMARY STEERING FEATURE. AFTER THAT...THE GLOBAL
MODELS SHOW THE RIDGE WEAKENING DUE TO THE COMBINED INFLUENCES OF
ATLANTIC TROPICAL STORM ISAAC MOVING OVER THE SOUTH-CENTRAL U.S.
AND A TROUGH MOVING TOWARD CALIFORNIA. THIS STEERING PATTERN SHOULD
CAUSE THE CYCLONE TO SLOW DOWN AND TURN NORTHWESTWARD. THE RIDGE
COULD REBUILD TO THE NORTHEAST OF THE SYSTEM BY THE END OF THE
FORECAST PERIOD CAUSING IT TO TURN BACK TO THE WEST-NORTHWEST. THE
OFFICIAL FORECAST IS NEAR THE CONSENSUS AIDS...TVCA AND TV15...AND
KEEPS THE CENTER OF THE CYCLONE WELL OFFSHORE OF THE COAST OF
MEXICO.

FORECAST POSITIONS AND MAX WINDS

INIT 27/2100Z 15.1N 107.0W 30 KT 35 MPH
12H 28/0600Z 15.6N 108.7W 40 KT 45 MPH
24H 28/1800Z 16.2N 110.6W 45 KT 50 MPH
36H 29/0600Z 16.6N 111.6W 50 KT 60 MPH
48H 29/1800Z 17.4N 112.2W 55 KT 65 MPH
72H 30/1800Z 19.0N 112.7W 60 KT 70 MPH
96H 31/1800Z 20.4N 113.7W 60 KT 70 MPH
120H 01/1800Z 22.0N 117.5W 55 KT 65 MPH

$$
FORECASTER CANGIALOSI
ILLENEA YES will be here


*clapping*
Patrap's watching us yay! plused #1485
Who will post the Re-number...
Isaac is only up to 70 mph.
Quoting Hoff511:


I drove through that too. NO FUN!
And they crazy south Florida drivers speed by you like nothing has happened....Geeez
1507. divdog
Quoting kmanislander:


That is the only open path at the moment. The plains high is a blocker in that direction. Winds always lag a pressure drop.
My local nws mentions a developing trough over Ohio tenn valley as a key player. Best way to see it on water vapor or some other way
TROPICAL STORM ISAAC FORECAST/ADVISORY NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
2100 UTC MON AUG 27 2012

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE HURRICANE WARNING FROM THE FLORIDA-ALABAMA BORDER TO DESTIN HAS
BEEN CHANGED TO A TROPICAL STORM WARNING.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* EAST OF MORGAN CITY LOUISIANA TO THE ALABAMA-FLORIDA BORDER...
INCLUDING METROPOLITAN NEW ORLEANS...LAKE PONTCHARTRAIN... AND LAKE
MAUREPAS

A HURRICANE WATCH IS IN EFFECT FOR...
* INTRACOASTAL CITY TO MORGAN CITY LOUISIANA

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* FROM THE ALABAMA-FLORIDA BORDER TO THE AUCILLA RIVER
* INTRACOASTAL CITY TO MORGAN CITY LOUISIANA

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* EAST OF SABINE PASS TO WEST OF INTRACOASTAL CITY LOUISIANA

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. PREPARATIONS TO PROTECT LIFE AND
PROPERTY SHOULD BE RUSHED TO COMPLETION.

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA.

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

TROPICAL STORM CENTER LOCATED NEAR 26.4N 86.2W AT 27/2100Z
POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 981 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 50NE 15SE 15SW 50NW.
34 KT.......150NE 150SE 80SW 180NW.
12 FT SEAS..180NE 180SE 180SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 26.4N 86.2W AT 27/2100Z
AT 27/1800Z CENTER WAS LOCATED NEAR 26.1N 85.9W

FORECAST VALID 28/0600Z 27.4N 87.5W
MAX WIND 70 KT...GUSTS 85 KT.
64 KT... 20NE 0SE 0SW 20NW.
50 KT... 60NE 20SE 20SW 60NW.
34 KT...165NE 150SE 80SW 180NW.

FORECAST VALID 28/1800Z 28.6N 89.0W
MAX WIND 80 KT...GUSTS 100 KT.
64 KT... 20NE 20SE 0SW 20NW.
50 KT... 60NE 50SE 30SW 60NW.
34 KT...180NE 150SE 80SW 180NW.

FORECAST VALID 29/0600Z 29.5N 90.0W...NEAR THE COAST
MAX WIND 85 KT...GUSTS 105 KT.
64 KT... 30NE 20SE 10SW 20NW.
50 KT... 60NE 60SE 40SW 60NW.
34 KT...180NE 150SE 80SW 150NW.

FORECAST VALID 29/1800Z 30.3N 90.7W...INLAND
MAX WIND 75 KT...GUSTS 90 KT.
50 KT... 60NE 60SE 40SW 40NW.
34 KT...180NE 150SE 80SW 110NW.

FORECAST VALID 30/1800Z 32.2N 91.8W...INLAND
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 60NE 130SE 30SW 40NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 175 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 31/1800Z 35.9N 92.1W...INLAND
MAX WIND 25 KT...GUSTS 35 KT.

OUTLOOK VALID 01/1800Z 38.7N 89.3W...INLAND
MAX WIND 20 KT...GUSTS 30 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 26.4N 86.2W

NEXT ADVISORY AT 28/0300Z

Not a hurricane ;/
ESTIMATED MINIMUM CENTRAL PRESSURE 981 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 50NE 15SE 15SW 50NW.
34 KT.......150NE 150SE 80SW 180NW.
12 FT SEAS..180NE 180SE 180SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

Oh boy...
1510. LargoFl
Quoting FrancesJeanne:
Port St. Lucie this afternoon. So glad to see this band finally moving offshore - crossing my fingers that it keeps right on going; enough is enough already!
there are going to be some amazing flooding pics coming out of eastern florida i bet..i for one cannot believe the rainfall amounts, we all thought..over here on the west coast..that it would be happening to US today..schools were all closed, states of emergency enacted..and boom..you folks got it...this sure is one strange storm alright, throw out the predictions right..this storm is going to do what HE wants to do
1511. Dsntslp
Quoting Hoff511:
Hey Everyone, on topic but a little bit of a sidetrack. I know storms, but just experienced in Port Saint Lucie, FL thunder and lightning like never before. It was a weird flash, not a bolt, followed by what could only be described as multiple sonic booms occurring simultaneously. To the point of shaking my patio doors. Not thinking conspiracies or anything crazy just wondering if anyone else is aware of or has experienced this phenomenon. I have been through plenty of storms and rolling thunder but this is beyond that exponentially.
Usually lightning striking a transformer and the resulting backfeed. It has an almost aura quality to it like a blue or green hovering type light that wells up and goes boom (your super sonic boom). Sometimes more than one boom. Hope this helps. :) I don't know all of the terminology but have observed many transformers being struck over the years. Sometimes the backfeed is so bad it blow people electronics and refrigerators etc... The reason behind power bar protection, IMO.
Quoting Pirate999:


I think Texas is going to get a lot of......heat.


Naturally. But the north winds will knock the humidity down a little. Take what I can get. :)
Quoting Thing342:
I wonder what the blog's reaction would be if the NHC doesn't make Isaac a hurricane.
Relieved for me. I think he does become a Hurricane but he won't be very strong. Right now he will be mainly a rainmaker and for areas that dont need rains they will get way too much.
1514. GetReal
Quoting Sfloridacat5:
Dr Masters just now on TWC - "not going to be a cat 2 today or tomorrow."


Funny what sometimes happens when you have to step away from a computer monitor for a television interview... LOL
Quoting bappit:
#1458 Water vapor showing the warming above the eye, too.


Matches the vortex message stating that the eye is open to the N.
Quoting TropicalAnalystwx13:
Isaac is only up to 70 mph.


This is frustrating
1517. Grothar
I'm too tired to go back to post 929 and plus Nea. If I put one here and said it belonged to him, does it count?
70MPH ts isaac
I'm a "lay person" and I have been here lurking since 2005 and haven't posted much at all but the only other time I had a gut feeling that a storm was going to be more than what ppl were anticipating 3 days out to landfall was Katrina. That is how I found this particular website because I couldn't understand why Katrina at the time was being so downplayed. HOWEVER, I didn't become a memnber until 2009. I posted earlier today that regardless whatever the storm is classified as, it is going to be bad d/t how big it is and the amount of rain/moisture and NOBODY should downplay this storm!
The NHC is waiting for surface winds to come up slightly before declaring this a hurricane.
Quoting Hypemachine:
What we here in the vernacular call a tropospheric vortex inducing a Burnuli effect in conjunction with the Coriolis effect due to Abram's huge rack causing a cat5 storm surge in my groin equalization of pressure caused by the evaporation transport of heat above 850 millibars layer inducing a relative wind speed of or above 3308.1 centimeters per second.




Hahaha
It's only a matter of time before the winds begin to coincide with the system's pressure.
1523. flcanes
Quoting NCHurricane2009:

Didn't we have a quick pressure drop to 990 mb last night...and we thought RI was starting...when in fact it seemed like a drop in the bucket after he only went to 65 mph winds?

Last night I was wondering if he was shrinking in size. I say nay...he is better modeled as a bigger storm with a more lax pressure gradient...so the pressure drops may perhaps push him to 70 mph...

nope, hurricane
On visible it's apparent that Isaac has wrapped a strand of dry air all of the way to his core...he gets an A for effort but he's racing with a restrictor plate...
Quoting Charliesgirl:


Hi! I am from Pearl River! sheltering in place. wish I had a generator.


Hey neighbor. Stay safe out there. hugs :)
Quoting AtHomeInTX:


Naturally. But the north winds will knock the humidity down a little. Take what I can get. :)
Texas had alot of heat last Sept too so this wont be any different
Quoting Pirate999:


I think Texas is going to get a lot of......heat.


And humidity.
Quoting TropicalAnalystwx13:
Isaac is only up to 70 mph.

SWEET...what did I tell ya...

See post 1500. He's a larger storm with lax pressure gradients...so the pressure is going to have to be lower than normal to get this to a hurricane. Not sayin it won't happen...but he's got more work to do...
Ridiculous... period.
OK...

who is in charge of getting the pitchforks?
Most interesting part of the advisory to me is the fact that he has slowed to 10 knots...........Not good in terms of longer time over water and potential for catastrophic flooding at landfall.
Isaac has gotta be one of the most frustrating storms of all time.
wow what a storm again... so far since last monday theres been 58 track changes and 18 different landfalls predicted and now they will use this storm to increase gas prices because of the oil rigs are being affected in the gulf someone is making a fortune off this storm
1534. flcanes
Quoting Hurricane12:
It's only a matter of time before the winds begin to coincide the system's pressure.

very much true
PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 981 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 50NE 15SE 15SW 50NW.
34 KT.......150NE 150SE 80SW 180NW.
12 FT SEAS..180NE 180SE 180SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

NO HURRICANE!!!!
1536. LargoFl
I knew you were in here Pat! Hope you are having a relaxing and wonderful time :)
1538. bappit
Quoting Wiiilbur:
Maybe some of you who are more experienced than me can help me understand something. According to the Cumulative Wind Map, all of south, southeast and southwest Florida are shown to have experienced winds in excess of tropical storm level (>39 mph). However, looking at the past history of the storm, with a NHC intensity of 60 mph as it passed Key West, I can't find a single National Weather Service station or offshore buoy that shows sustained winds that reached tropical storm intensity in any part of Florida, let alone anywhere near 60 mph. Maybe someone can help clarify this for me.

The cumulative wind map is created kind of arbitrarily by plotting the maximum radius of tropical storm force winds and connecting the dots. That maximum radius is an estimate to begin with. I love that phrase "connecting the dots" ... as if that is how logic works.
cat 2 forecast again!
Quoting CJ5:
L. Eye Character: Open in the north
M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)


This is not much better than any of the other recon reports we have had the past 96 hours. At least "ragged" is not in there. And it is open only on one side. Maybe he can eventually close up. It is the smallest diameter report we have had do that shows some improvement in that regard.


L. Eye Character: Open in the north
M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)


That's actually quite an accomplishment for Isaac during the daytime. Nighttime has generally been Isaac's friend for organization, only to lose what he gained when the sun comes up. I'm thinking he finally achieves Cat 1 hurricane status sometime tonight..
There hasn't been any outstanding data reported by Recon that would point towards the classification of a hurricane. Flight-level winds after the reduction, were still below 65kts, and there has only been 1 SFMR reading of 64kts. It's going to come down to the wire, and the only chance you have of it getting upgraded is if Stewart is writing the package lol.
Quoting nrtiwlnvragn:
Think they are going to get the Doc an "on air" coach.
lol...you think so?
He needs to loosen up but it's tough to be thrown into the mix in the middle of a weather event like this.
.
Do appreciate his level headed opinion as always...much preferred over the hopesters and hypesters.
Just got 8" at my house in Port Saint Lucie. WOW flooded everywhere.
1544. sar2401
Quoting Grothar:
I'm too tired to go back to post 929 and plus Nea. If I put one here and said it belonged to him, does it count?


Gro, glad to see you back. We missed you on the night shift. :)
Quoting sunlinepr:
Intensity forecast....

Not more than 90mph....



actually its 90 knots...105 mph
NHC can always issue a special update to increase winds/declare Isaac a hurricane. They are correct that Isaac is not showing much in the way of hurricane force winds at the surface. However, it will not be long.
1547. JeffM
NHC now saying Cat 2 at landfall.
Quoting CaicosRetiredSailor:
OK...

who is in charge of getting the pitchforks?

I can get ahold of a few stun guns
Quoting kwgirl:
With the water that is with this system and possible surge, is it wise to stay at a junction of three rivers?


Probably not but that's the only place we have to go. They didn't get ANY water with Katrina and like I said they have 3 generators. So I think we'll be fine. Thanks so much for you concern. :)
LAFAYETTE PARISH

Broussard

Sandbags are available for residents of Broussard at city hall, across the street from city hall and Deer Metal Subdivision. You have to bag them yourself, shovels are availlable.

Youngsville

The City of Youngsville has stocked four sand bag locations for the citizens of Youngsville. These sites have sand and sand bags for individuals to bag their own. Limit 15 bags each, please.

Bag-Your-own at the city Police Station 304 Fourth Street

Bag-Your-own the Public Works Building 310 Railroad Avenue

Bag-Your-Own at the Horse Arena across from Farmer's Bank - 412 Iberia Street (a.k.a. Hwy 92).

The fourth site is at the Youngsville sewer plant 416 Railroad Avenue. This site is reserved for elderly and individuals requiring assistance. There is assistance available until 4:00 PM to help load pre bagged sand into vehicles.
Quoting MiamiHurricanes09:
There hasn't been any outstanding data reported by Recon that would point towards the classification of a hurricane. Flight-level winds after the reduction, were still below 65kts, and there has only been 1 SFMR reading of 64kts. It's going to come down to the wire, and the only chance you have of it getting upgraded is if Stewart is writing the package lol.

Stewart wrote this.
Quoting jeffs713:

BNSF has been pulling trains from Galveston, but not from points inland.



I know I have heard and seen about 10 different trains. My husband said he listens and if they spend all that time and money to move them something is up. I guess they might be worried about the storm surge. We seen a huge ship leaving out yesterday and you could tell they where still working on it or something but they where getting it out of there.

sheri
Quoting Sfloridacat5:
Dr Masters just now on TWC - "not going to be a cat 2 today or tomorrow."


NHC new advisory just upped their forecast to a Cat 2 prior to landfall....

Showdown...The Doc vs the NHC....
Quoting MiamiHurricanes09:
There hasn't been any outstanding data reported by Recon that would point towards the classification of a hurricane. Flight-level winds after the reduction, were still below 65kts, and there has only been 1 SFMR reading of 64kts. It's going to come down to the wire, and the only chance you have of it getting upgraded is if Stewart is writing the package lol.


Even Stewart wasn't convinced.

An update could come at any time, though, it really wouldn't take much.
Quoting trHUrrIXC5MMX:
PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 981 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 50NE 15SE 15SW 50NW.
34 KT.......150NE 150SE 80SW 180NW.
12 FT SEAS..180NE 180SE 180SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

NO HURRICANE!!!!


It seems like it may make a run at being a strong category one at landfall.

At this point, it hasn't strengthened much over the past few days, but it has become much more better organized. The pressures are also extremely low for a strong tropical storm. It's really only a matter of time before the winds begin to match the barometric pressure.
and He didn't...

4:00 PM CDT Mon Aug 27
Location: 26.4°N 86.2°W
Moving: NW at 12 mph
Min pressure: 981 mb
Max sustained: 70 mph
For those leaving nola.. Traffic on i-10 east in nola east is backed up due to a shooting.. Take an alternate route if possible
Quoting FrancesJeanne:
Port St. Lucie this afternoon. So glad to see this band finally moving offshore - crossing my fingers that it keeps right on going; enough is enough already!


What intersection is that?
The park sign looks familiar...is it off Floresta?

Quoting CosmicEvents:
lol...you think so?
He needs to loosen up but it's tough to be thrown into the mix in the middle of a weather event like this.
.
Do appreciate his level headed opinion as always...much preferred over the hopesters and hypesters.


Brian kept throwing him softballs, and all he did was agree with him. With time, he will do fine.
NHC predicting a 90 MPH hurricane. Smart move. Glad they are not backing down from that just because it has taken this storm a bit longer to get together. At least they are scientific as opposed to reacting with every ebb and flow of each frame of NEXRAD/IR.
Seriously? NHC being too tight vested here.
Quoting trHUrrIXC5MMX:
PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 981 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 50NE 15SE 15SW 50NW.
34 KT.......150NE 150SE 80SW 180NW.
12 FT SEAS..180NE 180SE 180SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

NO HURRICANE!!!!

Yeah!!!

I wonder why some folks are so frustrated. I wouldn't want a storm to bomb out on my worst enemy....right? Maybe if this was over open waters out of shipping lanes its worth cheering on...but not this one IMO...but that's just me...

He's definelty an Ike-type kina dude...large and broad with more lax pressure gradient and no tight core. Slow strengthening...and lower than normal pressures are required to get the same amount of wind...Dr. M called this out yesterday....
Quoting TropicalAnalystwx13:
The NHC is waiting for surface winds to come up slightly before declaring this a hurricane.


HH coming up for another center fix. If the pressure is down again or even holding steady we should have Cat 1 winds sustained for 8 PM. The weak NE quad still poses a risk to the system but if the eyewall closes off on the North the winds should come up fairly quickly. The eye may still be open to the N on the next pass based upon available satellite presentation but real time may be different.
1566. will40
000
WTNT34 KNHC 272049
TCPAT4

BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT MON AUG 27 2012

...RECONNAISSANCE AIRCRAFT INDICATES ISAAC GETTING STRONGER...
SIGNIFICANT STORM SURGE THREAT EXPECTED FOR THE NORTHERN GULF
COAST...
Tweet form Dr. Knabb:

@NHCDirector

Large size and slow fwd motion of #Isaac as it comes ashore, regardless wind intensity, means big storm surge, inland flood threat
The pressure is at 981mb, one deep storm.
NHC trying to make Dr. Masters eat his words that it won't be a cat 2...well the nhc says it will again! LOL!
1570. flcanes
Quoting WALMARTPROFITSAGAIN:
wow what a storm again... so far since last monday theres been 58 track changes and 18 different landfalls predicted and now they will use this storm to increase gas prices because of the oil rigs are being affected in the gulf someone is making a fortune off this storm

who, nobody is in the gulf
other than maybe some clams
do clams make money?
Quoting auburnguy:
For those leaving nola.. Traffic on i-10 east in nola east is backed up due to a shooting.. Take an alternate route if possible


It has started.
Quoting TomballTXPride:
NHC predicting a 90 MPH hurricane. Smart move. Glad they are not backing down from that just because it has taken this storm a bit longer to get together. At least they are scientific as opposed to reacting with every ebb and flow or each frame or NEXRAD or IR.

They are predicting 100mph not 90
Quoting catastropheadjuster:



I know I have heard and seen about 10 different trains. My husband said he listens and if they spend all that time and money to move them something is up. I guess they might be worried about the storm surge. We seen a huge ship leaving out yesterday and you could tell they where still working on it or something but they where getting it out of there.

sheri


Yep. I live near some BNSF tracks, and my neighbors across the street both work for the BNSF... when a storm even thinks of threatening, they empty out galveston.
I'm surprised Isaac isn't a hurricane but this is a large windfield/low pressure system like Irene which had what seemed like very low windspeed for such low barometric pressure.
1576. LargoFl
Quoting LargoFl:
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
355 PM EDT MON AUG 27 2012

FLZ050-051-055-272045-
HILLSBOROUGH-PINELLAS-MANATEE-
355 PM EDT MON AUG 27 2012

...A SIGNIFICANT WEATHER ADVISORY HAS BEEN ISSUED FOR EAST CENTRAL
PINELLAS...NORTHEASTERN MANATEE AND WESTERN HILLSBOROUGH COUNTIES FOR
A STRONG THUNDERSTORM WITH STRONG WIND GUSTS VALID UNTIL 445 PM
EDT...

AT 351 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATES A
STRONG THUNDERSTORM LOCATED NEAR DUETTE...OR 22 MILES WEST OF
WAUCHULA...MOVING NORTHWEST AT 40 MPH WILL AFFECT DUETTE...LITTLE
MANATEE RIVER STATE PARK...SUN CITY CENTER AND WIMAUMA.

THIS INCLUDES INTERSTATE 75 BETWEEN EXITS 240 AND 256.

THIS INCLUDES INTERSTATE 275 BETWEEN EXITS 39 AND 52.

GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED WHICH CAN CAUSE UNSECURED
OBJECTS TO BLOW AROUND...SNAP TREE LIMBS AND CAUSE POWER OUTAGES.
TORRENTIAL RAINS WILL REDUCE VISIBILITY TO NEAR ZERO AND WILL CAUSE
PONDING OF WATER ON ROADWAYS.


&&


Thank you. Put the lawn furniture in to the pool.
1578. sar2401
Quoting Elena85Vet:


L. Eye Character: Open in the north
M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)


That's actually quite an accomplishment for Isaac during the daytime. Nighttime has generally been Isaac's friend for organization, only to lose what he gained when the sun comes up. I'm thinking he finally achieves Cat 1 hurricane status sometime tonight..


It sure wasn't last night. He looked worse than any time since getting into the Gulf at about 0300 CST.
1579. flcanes
Quoting will40:
000
WTNT34 KNHC 272049
TCPAT4

BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT MON AUG 27 2012

...RECONNAISSANCE AIRCRAFT INDICATES ISAAC GETTING STRONGER...
SIGNIFICANT STORM SURGE THREAT EXPECTED FOR THE NORTHERN GULF
COAST...

how strong?
Quoting Thing342:
I wonder what the blog's reaction would be if the NHC doesn't make Isaac a hurricane.
The typical closet forecaster wannabees will think they know more than the NHC.
The level headed members will watch and wait.
(comes back on the blog).Oh lookey what we have here?.Good news for the gulf with this one.Rain will be a issue though.I'm sure some of the mid-west states wouldn't complain if Isaac could give them some rain.
1582. bappit
Quoting kctinney:
I'm a "lay person" and I have been here lurking since 2005 and haven't posted much at all but the only other time I had a gut feeling that a storm was going to be more than what ppl were anticipating 3 days out to landfall was Katrina. That is how I found this particular website because I couldn't understand why Katrina at the time was being so downplayed. HOWEVER, I didn't become a memnber until 2009. I posted earlier today that regardless whatever the storm is classified as, it is going to be bad d/t how big it is and the amount of rain/moisture and NOBODY should downplay this storm!
]
Who downplayed Katrina?????
Quoting TropicalAnalystwx13:

Stewart wrote this.
Then you know that there isn't sufficient data to warrant an upgrade.

Without a doubt we'll have a hurricane by 11p.m though.
Quoting TomballTXPride:
NHC predicting a 90 MPH hurricane. Smart move. Glad they are not backing down from that just because it has taken this storm a bit longer to get together. At least they are scientific as opposed to reacting with every ebb and flow or each frame or NEXRAD or IR.

100 MPH again!!
Quoting STXHurricanes2012:
NHC trying to make Dr. Masters eat his words that it won't be a cat 2...well the nhc says it will again! LOL!

Really surprised Master's said that. Really surprised.
1586. CJ5
If I had a dollar for every time someone said and RI was coming, I would be rich. It has been said for the past 4 days with nothing. He just has been unable to close his core and until he does that he will not gain much strength.
Quoting Levi32:
Coolest loop in the world right now, set to fill the screen of a 15-inch laptop. You can play with the URL parameters.


amazing.
1588. barbamz
Quoting Hoff511:


Thanks for the concern, but no, it was not that either, unless my house got struck 10 time today.


Perhaps a rare ball lightning?
1590. flcanes
Quoting sar2401:


It sure wasn't last night. He looked worse than any time since getting into the Gulf at about 0300 CST.

yeah, dry air is eating up his east side
Isaac should be a hurricane before the night is out, and should peak as a Category 2 hurricane tomorrow afternoon. If it undergoes rapid intensification, a minimal Category 3 is possible.
Recon passing through the SE side and finding the same 70+ knot flight-level winds as it had in the rest of southern semi-circle. Compare these to the last SW pass around 90 minutes ago, where the highest flight-level winds were 55-60 knots. Isaac is strengthening very quickly. SFMR shows winds haven't got down to the surface yet, but they will, and soon.

Would at all be suprised to see sub-980 on this pass.
Quoting Felix2007:

They are predicting 100mph not 90

I see that. I was just going by the discussion and forecast points. Isn't that the official?
This dude is about to take off...

1595. Dsntslp
Frances Jeanne, (Treasure Coast and others local to me)

Do you have power?
Do you need anything?

I have lots of ice and a deep freeze if you need it to put your food in here.
I have a generator too if it starts to look like your power will be off for any length of time.

You can email me at (my screen name here) @yahoo.com if you want.
Quoting Bluestorm5:


*clapping*


Not to take away from Nea, sadly my fellow comrades sunk so far today that for one of us to say something smart and with humility and sincerity that one person looks like he should be awarded a Noble Peace Prize.

Nea's outlook and sensitivity for women and their feelings should be the rule not the exception.
...and now we wait for the discussion. LOL
Quoting TomballTXPride:
NHC predicting a 90 MPH hurricane. Smart move. Glad they are not backing down from that just because it has taken this storm a bit longer to get together. At least they are scientific as opposed to reacting with every ebb and flow of each frame of NEXRAD/IR.


Actually, they're predicting 100mph now.
Quoting hurricanejunky:
I'm surprised Isaac isn't a hurricane but this is a large windfield/low pressure system like Irene which had what seemed like very low windspeed for such low barometric pressure.


Isaac...Irene...and Ike...yep...

What's up with these recent 'I' storms that wanna be this way....LOL
Still a TS 60 kt.
10 mph higher than last pass in SE side of Isaac... whoa.
Quoting TomballTXPride:

I see that. I was just going by the discussion and forecast points. Isn't that the official?

Yes it is official from NHC site.
Quoting jascott1967:


And humidity.
Incorrect being on West side of a tropical system all the Dry Air is brought down with Northeast Winds, it will be nice and cool in the mornings and hot and dry in the afternoons.


Thanks for correction... scale is in knots

85knots = aprox. 98mph....

So the forecast is Cat1 or no more than 100 mph at landfall....

1606. flcanes
Quoting jascott1967:


Not to take away from Nea, sadly my fellow comrades sunk so far today that for one of us to say something smart and with humility and sincerity that one person looks like he should be awarded a Noble Peace Prize.

Nea's outlook and sensitivity for women and their feelings should be the rule not the exception.

( eyes tear up)
What are the models looking like. Any chance this turns more northward toward ms/ls coast or ms/al line?
55kt SFMR winds with some 60kt flight-level winds in this data set.

204830 2555N 08529W 8434 01421 //// +213 //// 231055 056 055 002 05
Quoting washingtonian115:
(comes back on the blog).Oh lookey what we have here?.Good news for the gulf with this one.Rain will be a issue though.I'm sure some of the mid-west states wouldn't complain if Isaac could give them some rain.
Storm Surge is going to be huge, though... Ike was a Category 2 with Category 4 surge. Same thing is possible with this storm.
1611. flcanes
Quoting WALMARTPROFITSAGAIN:
it was supposed to hit cat 1 strength like 30 different times after it clears land masses and this and that and so far still a tropical storm well its going this way models are all in agreement but wait now they changedonce it clears the dry air it will strengthen ( nope it didnt ) once it clears P.R. well it never hot pr once it clears hati ot will strngthen (nope ) once it clears tip of cuba it will stengthen ( nope) once it hits the straits it will strngthen ( nope once it clears the keys now it will strenghthen ( nope) good lord these forcasters suck bad and do this every year with every storm total idiots making money thats all this was

sometimes things happen, like with charley
Quoting auburnguy:
For those leaving nola.. Traffic on i-10 east in nola east is backed up due to a shooting.. Take an alternate route if possible

Is there a mandatory evac for NOLA? I haven't been checking any news sources all day here at work....(except for this blog)...
Quoting CybrTeddy:


Actually, they're predicting 100mph now.

Okay.

I see it now.

My bad.

Still a wise choice. This thing has never looked so primed and ready. Isaac will be putting on his game face.
Quoting Stoopid1:
Seriously? NHC being too tight vested here.


They can only work with the information they have.

Although I agree that this should be named a hurricane so more people take it serious, they cannot just magically invent data and hope it comes true. They have to keep some level of authenticity.
What did I tell you guys?

...RECONNAISSANCE AIRCRAFT INDICATES ISAAC GETTING STRONGER... SIGNIFICANT STORM SURGE THREAT EXPECTED FOR THE NORTHERN GULF COAST... ...U.S. Warnings in Effect...
4:00 PM CDT Mon Aug 27
Location: 26.4°N 86.2°W
Moving: NW at 12 mph
Min pressure: 981 mb
Max sustained: 70 mph
1616. Gorty
I kind a figured they were gonna keep it as a TS. 80-85 mph flight level is what like 10-15 mph lower at the surface? So 70-75 mph surface wins. So really, it was only a 50/50 chance.
Quoting Felix2007:

Yes it is official from NHC site.

I see it.

Nevermind.

Thanks.
Quoting Bluestorm5:
Storm Surge is going to be huge, though... Ike was a Category 2 with Category 4 surge. Same thing is possible with this storm.

Yeah...good point...so I hope Isaac doesn't get as strong as Ike did...
Quoting MississippiWx:
This dude is about to take off...


I don't think so, the NE quad is to weak and dry to allow anything more than slow, steady intensification until landfall. I'm with Doc on this one, Cat 1 peak.

1620. flcanes
Quoting Bluestorm5:
Storm Surge is going to be huge, though... Ike was a Category 2 with Category 4 surge. Same thing is possible with this storm.

if it stays ts, still 10 ft surge
cat1=15
cat2=20
you get the idea
Quoting Bluestorm5:
Storm Surge is going to be huge, though... Ike was a Category 2 with Category 4 surge. Same thing is possible with this storm.

And as long as he sits out there spinning, the beaches are going to get beat to pieces before it even comes ashore.
Yea issac is a hurricane has been for a few hours 981 pressure normall equates to a strong cat 1 this thing is about to ramp up
ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM ISAAC DISCUSSION NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT MON AUG 27 2012

THE MUCH ANTICIPATED INTENSIFICATION PROCESS APPEARS TO HAVE FINALLY
STARTED BASED ON REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE
AIRCRAFT AND FROM NEARBY NOAA BUOY 42003. THE CENTRAL PRESSURE HAS
DECREASED BY AT LEAST 7 MB SINCE THE PREVIOUS ADVISORY. THE HIGHEST
FLIGHT-LEVEL WINDS OBSERVED HAVE BEEN 74 KT IN THE SOUTHWEST
QUADRANT AND THE HIGHEST BIAS-ADJUSTED SFMR WINDS ARE NEAR 58 KT.
THESE DATA SUPPORT AN INTENSITY OF 60 KT.

ISAAC WOBBLED WESTWARD THIS AFTERNOON...BUT A REPRESENTATIVE INITIAL
MOTION ESTIMATE IS 305/10. THE LATEST 12Z NHC MODEL GUIDANCE IS IN
BETTER AGREEMENT ON A WEST-NORTHWEST TO NORTHWEST MOTION TOWARD THE
SOUTHEAST LOUISIANA AND MISSISSIPPI COASTAL AREAS OVER THE NEXT
36-48 HOURS. AFTER 48 HOURS...HOWEVER...THE MODEL GUIDANCE REMAINS
DIVERGENT ON THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO DIG
SOUTHEASTWARD FROM THE UPPER MIDWEST AND INTO THE MID-ATLANTIC
REGION...FOLLOWED BY A RIDGE BUILDING IN BEHIND THE TROUGH. THE GFS
AND ECMWF...OUR MOST RELIABLE MODELS... NOW HAVE VERY SIMILAR
SOLUTIONS THROUGH DAY 5...AND THE OFFICIAL FORECAST TRACK IS
BETWEEN THOSE TWO MODELS.

SATELLITE DATA INDICATE ISAAC HAS BECOME BETTER ORGANIZED OVER THE
PAST 6 HOURS WITH THE DEVELOPMENT OF A CENTRAL DENSE OVERCAST CLOUD
PATTERN OVER THE CENTER ALONG WITH A DEVELOPING EYE IN RECON DATA.
SATELLITE DATA T-NUMBERS HAVE INCREASED TO T4.5/77 KT FROM TAFB AND
SAB. RECON WIND DATA INDICATE THE RADIUS OF MAXIMUM WINDS HAS ALSO
PULLED INWARD TO ABOUT 30 N MI. ALTHOUGH ADDITIONAL CONVECTION HAS
BEEN DEVELOPING IN THE NORTHEASTERN QUADRANT...DRY MID-LEVEL AIR
STILL LURKS JUST TO THE EAST AND SOUTHEAST OF THE CDO FEATURE...
WHICH COULD BE ENTRAINED INTO THE INNER CORE AT ANY TIME AND
DISRUPT THE DEVELOPMENT PROCESS. DUE TO THE PROXIMITY OF DRY
AIR...THE INTENSITY FORECAST INDICATES ONLY MODEST DEVELOPMENT FOR
THE NEXT 24 HOURS. HOWEVER...STRENGTHENING IS EXPECTED TO CONTINUE
RIGHT UP UNTIL LANDFALL OCCURS DUE TO THE VERY WARM WATERS THE
CYCLONE WILL BE PASSING OVER AND THE VERY FAVORABLE UPPER-LEVEL
OUTFLOW REGIME THAT ISAAC IS FORECAST TO DEVELOP BY 24 HOURS. THE
INTENSITY FORECAST IS JUST SLIGHTLY HIGHER THAN THE MODEL GUIDANCE.

BECAUSE SIGNIFICANT HAZARDS EXTEND WELL AWAY FROM THE CENTER...IT IS
IMPORTANT NOT TO FOCUS ON THE EXACT FORECAST TRACK. THE SLOW FORWARD
SPED OF AROUND 5 KT AFTER LANDFALL WILL RESULT IN A HEAVY RAIN AND
FLOOD SITUATION FOR PORTIONS OF THE CENTRAL GULF COAST AND LOWER
MISSISSIPPI VALLEY REGIONS.

FORECAST POSITIONS AND MAX WINDS

INIT 27/2100Z 26.4N 86.2W 60 KT 70 MPH
12H 28/0600Z 27.4N 87.5W 70 KT 80 MPH
24H 28/1800Z 28.6N 89.0W 80 KT 90 MPH
36H 29/0600Z 29.5N 90.0W 85 KT 100 MPH...NEAR THE COAST
48H 29/1800Z 30.3N 90.7W 75 KT 85 MPH...INLAND
72H 30/1800Z 32.2N 91.8W 35 KT 40 MPH...INLAND
96H 31/1800Z 35.9N 92.1W 25 KT 30 MPH...INLAND
120H 01/1800Z 38.7N 89.3W 20 KT 25 MPH...INLAND

$$
FORECASTER STEWART
Quoting tropicfreak:
What did I tell you guys?

...RECONNAISSANCE AIRCRAFT INDICATES ISAAC GETTING STRONGER... SIGNIFICANT STORM SURGE THREAT EXPECTED FOR THE NORTHERN GULF COAST... ...U.S. Warnings in Effect...
4:00 PM CDT Mon Aug 27
Location: 26.4°N 86.2°W
Moving: NW at 12 mph
Min pressure: 981 mb
Max sustained: 70 mph


You've been saying it all along.

CybrTeddy as well.

You guys are 100% correct, too.
Quoting WALMARTPROFITSAGAIN:
it was supposed to hit cat 1 strength like 30 different times after it clears land masses and this and that and so far still a tropical storm well its going this way models are all in agreement but wait now they changedonce it clears the dry air it will strengthen ( nope it didnt ) once it clears P.R. well it never hot pr once it clears hati ot will strngthen (nope ) once it clears tip of cuba it will stengthen ( nope) once it hits the straits it will strngthen ( nope once it clears the keys now it will strenghthen ( nope) good lord these forcasters suck bad and do this every year with every storm total idiots making money thats all this was


Ummm... it was 60 mph when it exited Haiti and now it is 70 mph, BOGUSTRACK NOSTORMINFLORIDA. Pressures have lowered a lot since then.

Ignorance and trolling are bliss.
Quoting WALMARTPROFITSAGAIN:
it was supposed to hit cat 1 strength like 30 different times after it clears land masses and this and that and so far still a tropical storm well its going this way models are all in agreement but wait now they changedonce it clears the dry air it will strengthen ( nope it didnt ) once it clears P.R. well it never hot pr once it clears hati ot will strngthen (nope ) once it clears tip of cuba it will stengthen ( nope) once it hits the straits it will strngthen ( nope once it clears the keys now it will strenghthen ( nope) good lord these forcasters suck bad and do this every year with every storm total idiots making money thats all this was


And yet you still choose to follow their forecasts...
1627. flcanes
Quoting MAweatherboy1:

I don't think so, the NE quad is to weak and dry to allow anything more than slow, steady intensification until landfall. I'm with Doc on this one, Cat 1 peak.


i stick with you, and the 15 foot storm surge
i cant believe people on here get sucked into watching this crap for hours everyday what a waste of time these forcasters suck and always have sucked and panic people every year for nothing but to create retail stimulation and people havent seen this year after year dont people know that walmart and home depot are the 2 biggest sponsors of the weather channel and home depot by now this crap happens with every storm every year its definetly going here then a change then another change wake up people and get a life instead of sitting in here 24/7 its all a scam and bs
Quoting MAweatherboy1:

I don't think so, the NE quad is to weak and dry to allow anything more than slow, steady intensification until landfall. I'm with Doc on this one, Cat 1 peak.



I concur.

It is slowly organizing, but I don't think RI or anything of that nature is expected or should be expected.
1630. airmet3
Quoting Thing342:
I wonder what the blog's reaction would be if the NHC doesn't make Isaac a hurricane.


Check out the reaction from yesterday afternoon. I expect similar, though somewhat more muted and hopefully more respectful.
Hey! anyone else watching Dr.Masters on TWC?

I am thinking a strengthening upper level or lower level Cat 1 or 2 could be worse than a Cat weakening as it comes ashore, so I think its important to note this storm most likely will be strengthening as it hits land.
Now that Isaac is certain to become a hurricane, it'll will keep the 2012 pattern going: save for Alberto, all the storms with male names have become hurricanes, and all those with female names have topped out as tropical storms:

Beryl: Tropical storm
Chris: Hurricane
Debby: Tropical storm
Ernesto: Hurricane
Florence: Tropical storm
Gordon: Hurricane
Helene: Tropical storm
Isaac: Hurricane
Joyce: Tropical storm
Kirk: ???
Quoting bappit:
]
Who downplayed Katrina?????


A TON of ppl on Fox Hurricane chat.......why I started googling about hurricanes and found this website. There were some ppl on here as well (some obviously trolls). Please don't ask me to recall from 2005 d/t I don't remember!
1635. flcanes
Quoting HurrikanEB:


And yet you're still following their forecasts...

that makes no sense, with his comment
Love the wording from Stewart. Lol.

THE MUCH ANTICIPATED INTENSIFICATION PROCESS APPEARS TO HAVE FINALLY
STARTED BASED ON REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE
AIRCRAFT AND FROM NEARBY NOAA BUOY 42003.
1637. will40
Quoting flcanes:

how strong?


it will be in the discussion
Guys and girls remember. The true measure of of storms strhenth is it's Barometric pressure. So with a 4 millibar drop - in a way Issac is going through RI. Don't worry be patient and the winds will eventually catch up with the pressure readings.
Quoting NCHurricane2009:

Is there a mandatory evac for NOLA? I haven't been checking any news sources all day here at work....(except for this blog)...


Yes
Quoting MississippiWx:
This dude is about to take off...



O_o

Quoting Bluestorm5:
10 mph higher than last pass in SE side of Isaac... whoa.


O_o

I'll believe it when I see it...because last afternoon I thought Isaac was about to take off. This is the firs time though I've heard of a wind increase like that....so now I am intrigued....
Live from Biloxi. Spent the day assisting the disabbilities community at the LIFE center in Biloxi and letting local FD and shelters know we are here and will be available for evac assistance tomorrow.
Quoting BeanTech:


What intersection is that?
The park sign looks familiar...is it off Floresta?


Yep, that's Floresta between Thornhill and West Virginia.
Quoting Hurricane12:
Love the working from Stewart. Lol.

THE MUCH ANTICIPATED INTENSIFICATION PROCESS APPEARS TO HAVE FINALLY
STARTED BASED ON REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE
AIRCRAFT AND FROM NEARBY NOAA BUOY 42003.
I am telling you he reads the blog.
1644. Michfan
Good evening all. What i miss so far today? Was too busy at work to check in.
Quoting MAweatherboy1:

I don't think so, the NE quad is to weak and dry to allow anything more than slow, steady intensification until landfall. I'm with Doc on this one, Cat 1 peak.


nhc says low cat 2 though
Beautiful...
Quoting MississippiWx:
This dude is about to take off...


As long as it doesn't intensify too fast, in which case it would pull in dry air and completely collapse its core.
With this storm, ANYTHING is still possible. This has been truly a bizarre storm. One of the strangest I've ever tracked. Don't be surprised if Isaac still has a couple more tricks up his sleeve. It can easily still attain category 2 status, but I think anything beyond that is extremely slim. Although who knows.

I do think that if he does peak at category 3, it won't be during his time approaching the coast at landfall. I'm sure it'll be out 80-120 miles offshore. But even then he can still carry enough momentum in with a huge surge. Plus he is huge so he will take long to weaken just like he's been taking to get going.
So the pressure has dropped 7 mb and wind up 5 mph since 11am, with 54-60 hours til landfall, thats 95-100mph landfall, right on target with NHC, so expect this rate til landfall.
1651. flcanes
Quoting kctinney:


A TON of ppl on Fox Hurricane chat.......why I started googling about hurricanes and found this website. There were some ppl on here as well (some obviously trolls). Please don't ask me to recall from 2005 d/t I don't remember!

i don't remember either
Quoting MississippiWx:
This dude is about to take off...


Cat2 is seeming more likely now, something is about to happen.
1653. help4u
100 mph winds is a cat2,i will go with the national hurricane center,has anyone ever see a hurricane stall and sit in one place for 24 hrs. This is not good for New Orleans.



Dayton International Speedway

In preparation for Isaac DIS welcomed 5,000 workers and 2,500 trucks from as far as Wyoming, Texas and Pennsylvania before embarking on their individual assignments. This FPL Connect pre-positioning at DIS marks the largest to date.
Stacy Stewart


He is a good forecaster
Quoting reedzone:
Ridiculous... period.



What should it have been? 75, 80? a Hurricane? How does the lack of a hurricane in their advisory effect you personally? Does it cause human lives to be in danger? The media is doing a great job of publicizing the storm and it's potential impacts. What's the issue?
Quoting NCHurricane2009:

Is there a mandatory evac for NOLA? I haven't been checking any news sources all day here at work....(except for this blog)...

No, there is not.

NOLA.com (news)
1658. Michfan
I have a feeling that dry air slot is going to limit its RI. It needs to mix that out and fast.
1659. airmet3
Quoting NCHurricane2009:

Is there a mandatory evac for NOLA? I haven't been checking any news sources all day here at work....(except for this blog)...


This morning on TWC, one of the city officials said they do not order mandatory evacuation unless it is a high end Cat 3.
well i guess if you consider a 10mph increase over almost 3 days is RI you will say RI when it makes landfall as a cat 1...not my idea of RI, but whatever this storm has been a disappointment since day 1
Im going to post pictures of the lake with reference points that some of you who live around me know of.
Gimme 30 minutes at least
STRENGTHENING IS EXPECTED TO CONTINUE RIGHT UP UNTIL LANDFALL OCCURS DUE TO THE VERY WARM WATERS THE CYCLONE WILL BE PASSING OVER

Folks on/near the coast in LA/MS/AL should pay close attention to this NHC statement and plan accordingly and not wait until the last minute if you are still on the bubble and expecting a weak Cat 1.......
Quoting WCSCTVCharleston:
Yea issac is a hurricane has been for a few hours 981 pressure normall equates to a strong cat 1 this thing is about to ramp up


There are 981 mb cyclones frequently across the globe in non-tropical form...yet they are not as windy as a hurricane. Its about pressure gradient...not central pressure. If a storm is spread out...it has a lower pressure gradient (and lower wind) for same central pressure.

So its not a hurricane alone by merit of central pressure value. But yeah...he is really close. Maybe 979 mb will finally get him to cat 1...
1664. flcanes
Quoting WxNerdVA:

eyewall?
Quoting StormJunkie:
Live from Biloxi. Spent the day assisting the disabbilities community at the LIFE center in Biloxi and letting local FD and shelters know we are here and will be available for evac assistance tomorrow.

Great work is all I have to say. The world needs more people like you.
I still see this becoming a 105 mph Hurricane! Mid cat 2 who agrees??
Next vortex is going to say "eye open to the NW or W"..

The pressure is going to be interesting on this one.. it doesn't usually take long for a storm to intensify from 1 to 2.
1668. flcanes
Quoting weathermanwannabe:
STRENGTHENING IS EXPECTED TO CONTINUE RIGHT UP UNTIL LANDFALL OCCURS DUE TO THE VERY WARM WATERS THE
CYCLONE WILL BE PASSING OVER


Folks on/near the coast in LA/MS/AL should pay close attention to this NHC statement and plan accordingly and not wait until the last minute if you are still on the bubble and expecting a weak Cat 1.......

keep up on the attention
Quoting MAweatherboy1:

I don't think so, the NE quad is to weak and dry to allow anything more than slow, steady intensification until landfall. I'm with Doc on this one, Cat 1 peak.



That same dry air has been present during this 3mb drop in the past hour. It's a fragile situation for sure, but the core seems well cut-off from any dry air for now.
Structure is improving and winds increasing, looks great.

I think it's trying to form an eye yes?

It looks like some sort of eye feature is trying to develop, which is definitely an indicator of it intensifying and of the possibility of future intensification.

The Northeastern and Southeastern section of the storm seem a little ragged still, but I am sure they will fill in slowly, at least this seems to be indicated on the radar.

I would not be surprised if this storm becomes a 80-85 mph storm by late tonight or tomorrow, and then perhaps become a 95-100 mph storm later tomorrow afternoon before landfall.
Quoting sar2401:


It sure wasn't last night. He looked worse than any time since getting into the Gulf at about 0300 CST.


Yeah. You are right, last night is an exception.

I still think Isaac get there tonight. Like Kman says maybe even the 8pm
Quoting TropicalAnalystwx13:

As long as it doesn't intensify too fast, in which case it would pull in dry air and completely collapse its core.


When hasn't this been ingesting dry air?

My point exactly
Quoting help4u:
100 mph winds is a cat2,i will go with the national hurricane center,has anyone ever see a hurricane stall and sit in one place for 24 hrs. This is not good for New Orleans.
Danny in 1997 sat an spun in Mobile bay for a long time.
1676. drs2008
Quoting TomballTXPride:

Great work is all I have to say. The world needs more people like you.
Hi Storm Junkie. Im on the ride out team at the VA. Good luck and Thanks!
Quoting CaicosRetiredSailor:

Where was that taken?
Quoting TomballTXPride:

Great work is all I have to say. The world needs more people like you.
This is unrelated but my grandma lives in tomball
I think he's slowing down... Could just be the way convection is changing, but I don't think he's moving nearly as fast as earlier.
Quoting CJ5:
If I had a dollar for every time someone said and RI was coming, I would be rich. It has been said for the past 4 days with nothing. He just has been unable to close his core and until he does that he will not gain much strength.


How about SI... Slow intensification.
ISAAC WOBBLED WESTWARD THIS AFTERNOON...BUT A REPRESENTATIVE INITIAL
MOTION ESTIMATE IS 305/10


OK lets give the wobble-casters some love!
Quoting TheHurricaneDundee:

I think it's trying to form an eye yes?

Sure looks like it's on it's way. Noticed your only a couple days signed up after me. Here's a couple great visible links to follow Isaac. Usually between now and sundown is the best time to watch these tops shoot and billow in the sky. Looks like Isaac is ready to put on a show for us.

Link

Link
Quoting STXHurricanes2012:
I still see this becoming a 105 mph Hurricane! Mid cat 2 who agrees??

Last afternoon...I thought he'd bomb out to cat 4...then I changed my mind this morning and agreed with Dr. M on nothing past cat 1...so I don't know what to think anymore....

All I know is I need to learn more....having 2 forecasts one way and the other means only 1 is right and 1 is wrong...so that is less skill....
1684. nolajet
Jeff beat me, but my post:

Quoting NCHurricane2009:

Is there a mandatory evac for NOLA? I haven't been checking any news sources all day here at work....(except for this blog)...


No there isn't. Link>From Nola.com

As ready as I will be. Now the waiting, which sucks more. Can't believe I am getting called in to work tomorrow. A coffee shop is not going to generate revenue in 40mph winds. And I'm the lucky guy that gets to walk home in it. Just like 7 years ago... exactly the same situation. Better results this time though. :)
Quoting wxchaser97:
Structure is improving and winds increasing, looks great.



It still looks a little ragged in the Northeastern quadrant due to dry air most likely, but if that anticyclone can slip down Southwest over the center of circulation then this storm can become mighty powerful.

This thing could potentially erupt if it can consolidate a strong inner core, although I am expecting it to be a more steady process of strengthening.

It still needs to fill in that Northeastern Quadrant before we can even consider Rapid intensification.
Quoting STXHurricanes2012:
I still see this becoming a 105 mph Hurricane! Mid cat 2 who agrees??


maybe not mid cat 2, but i am on the cat 2 train with ya.
Quoting TheHurricaneDundee:
This is unrelated but my grandma lives in tomball

LOL. Small world.
i think we could see 120 too 130mph at winds at land fall its slowing down wish would all so give it more time overe water
Quoting weatherh98:


Yes

No
1690. linkays
I know this storm is NOT coming near the Corpus Christi area but does anyone think it might send some rain? I can't figure out how big it is.....size not wind speed or anything like that. I'm sorry if anyone thinks this is a dumb question but we're just so desperate for rain.
I'm a little worried that SOME people have kind of dismissed Isaac as potentially a non-issue. The facts are that the storm will intensify right up until landfall...and it is worth reiterating that intensity forecasts are extremely vulnerable to large errors, even in the short term.
Quoting Dsntslp:
Frances Jeanne, (Treasure Coast and others local to me)

Do you have power?
Do you need anything?

I have lots of ice and a deep freeze if you need it to put your food in here.
I have a generator too if it starts to look like your power will be off for any length of time.

You can email me at (my screen name here) @yahoo.com if you want.

Still have power (and a/c again, thank god, after it being out since Saturday!)and all is well - that's very kind of you, though, thank you!
1693. acl8610
Quoting STXHurricanes2012:
I still see this becoming a 105 mph Hurricane! Mid cat 2 who agrees??

I agree, the core of the storm is disassociating from the activity over FL and the Atlantic, leaving a smaller COC that could spin up faster than it would have otherwise...
Quoting TheHurricaneDundee:
Hey! anyone else watching Dr.Masters on TWC?
Yes I saw him. Never knew he was so tall. Or is Bryan Norcross just short?
Quoting linkays:
I know this storm is NOT coming near the Corpus Christi area but does anyone think it might send some rain? I can't figure out how big it is.....size not wind speed or anything like that. I'm sorry if anyone thinks this is a dumb question but we're just so desperate for rain.


Not a dumb question... I doubt you'll see anything.
Quoting Pirate999:


How about SI... Slow intensification.


hahahaha

SI FLAG: ON
Quoting linkays:
I know this storm is NOT coming near the Corpus Christi area but does anyone think it might send some rain? I can't figure out how big it is.....size not wind speed or anything like that. I'm sorry if anyone thinks this is a dumb question but we're just so desperate for rain.

I doubt much of TX (aside from the very far eastern end) will get any rain from Isaac. His exact landfall point will make all the difference, as that influences his track post-landfall.

Sadly though, I think Corpus Christi won't get lucky.
Quoting jeffs713:

Where was that taken?


Looks like Daytona International Speedway
1699. bappit
Quoting kctinney:


A TON of ppl on Fox Hurricane chat.......why I started googling about hurricanes and found this website. There were some ppl on here as well (some obviously trolls). Please don't ask me to recall from 2005 d/t I don't remember!

A forum is like an ensemble model but with even more outliers.
Quoting NCHurricane2009:


There are 981 mb cyclones frequently across the globe in non-tropical form...yet they are not as windy as a hurricane. Its about pressure gradient...not central pressure. If a storm is spread out...it has a lower pressure gradient (and lower wind) for same central pressure.

So its not a hurricane alone by merit of central pressure value. But yeah...he is really close. Maybe 979 mb will finally get him to cat 1...




Just going by SS scale and referring to tropical cyclones
Isaac is the best looking Tropical Storm I've seen...
Quoting MAweatherboy1:
I think he's slowing down... Could just be the way convection is changing, but I don't think he's moving nearly as fast as earlier.



He has slowed down 3 MPH since the last report, and I would expect it to slow down as it reaches the coast, which is due to the fact it will be feeling the pressure of the two highs.

I think that if it becomes slower it will allow it a bit more time to organize over water and overall will allow it to slowly get its act together.

A slow moving storm just makes this situation much worse.
Bolaven is heading into the Koreas... He's not nearly the monster he was a few days ago but he's still a massive system and a typhoon... damage will be severe.

Quoting avthunder:
Yes I saw him. Never knew he was so tall. Or is Bryan Norcross just short?


Jeff is quite tall....I'm 6'2" and he dwarfs me...
Quoting avthunder:
Yes I saw him. Never knew he was so tall. Or is Bryan Norcross just short?


He didn't look very comfortable..
Quoting nrtiwlnvragn:


Looks like Daytona International Speedway

Yep. The text was posted after I quoted it... too fast on the "post" button.
No mandatory evacuation for New Orleans, but those who want to urged to leave now
http://www.nola.com/hurricane/index.ssf/2012/08/n o_mandatory_evacuation_for_ne.html
1708. help4u
Official forcast has it at cat 2 at landfall.100 mph gusts too 115.
@weatherchannel

BREAKING NOW: President Obama directs @FEMA to give LA, MS & AL governors the resources they need
Quoting TomballTXPride:

Sure looks like it's on it's way. Noticed your only a couple days signed up after me. Here's a couple great visible links to follow Isaac. Usually between now and sundown is the best time to watch these tops shoot and billow in the sky. Looks like Isaac is ready to put on a show for us.

Link

Link

I Just moved from Texas in 2010. I now live in NC. It's almost like the "I" stormms don't like me.(Ike, Irene...)
Quoting wxchaser97:

Cat2 is seeming more likely now, something is about to happen.

People of NOLA are lucky people that dry air is present in upper levels
Quoting linkays:
I know this storm is NOT coming near the Corpus Christi area but does anyone think it might send some rain? I can't figure out how big it is.....size not wind speed or anything like that. I'm sorry if anyone thinks this is a dumb question but we're just so desperate for rain.

Unlikely...just increase in swells at the coast and dry air resulting in temps rising to 100 or more the next few days as the dry n/nw flow from isaac filters in.
ANOTHER LARGE AND STRONG TROPICAL WAVE IS FOLLOWING THE TRACK OF ISAAC. THIS COULD BE THE BIG CAPE VERDE STORM
Quoting STXHurricanes2012:
I still see this becoming a 105 mph Hurricane! Mid cat 2 who agrees??


Storms have been slow to develope this season and although the gulf waters are warm there are no deep water eddys for it to pass at current. I see a low to moderate CAT 1 at landfall. The NHC has pretty much had this storm pegged from the beginning and that's what they've been calling for. See no reason to deviate.
I uploaded a couple flood photos to my photos here but have no idea how to post them to here
...ok lets take a 2 second break from Isaac to say this: TD Nine E has formed and will prob bcome the next storm in the e Pac...Sorry for the interruption adn now back to Isaac
Traffic is HORRIBLE this is exactly why we shouldnt have had school, you add another 5000 cars to clogged roads. With clouds rolling in and winds on the rise people will start getting antsy and scared

The ants are lunatics
Quoting reedzone:
Isaac is the best looking Tropical Storm I've seen...

IIRC, someone mentioned on here earlier that Wilma had the lowest pressure as a TS before she became a hurricane. Not that this is Wilma. And bringing up that name still gives people chills down their spine. Either way, it's a pretty cool nugget.
Quoting WCSCTVCharleston:




Just going by SS scale and referring to tropical cyclones

Yeah...I am suprised though that the SS scale has central pressure as a reference value...I'd have just tossed those out if I had contributed to it...because its the wind (not the pressure value) that causes the tangible damage the SS scale is based on.

I guess the pressure values on the SS scale represent the statistical 90th percentile of storms in that category...
Quoting AllStar17:
I'm a little worried that SOME people have kind of dismissed Isaac as potentially a non-issue. The facts are that the storm will intensify right up until landfall...and it is worth reiterating that intensity forecasts are extremely vulnerable to large errors, even in the short term.




I agree, especially since this storm could intensify into a mid level Cat 2 right as it nears the coast, which can catch people off guard.

Katrina created its most destruction with storm surge, and storm surge and flooding rains always tend to be the most devastating elements of tropical cyclones.

Due to the large nature of this storm and its general slow movement it has the capacity to be much more destructive in those elements than the actual strength of this storm would indicate.
JeffMasters has created a new entry.
Quoting reedzone:
Isaac is the best looking Tropical Storm I've seen...

Nah....what about Fay 2008 when she was near Lake Okechobee? Here tropical storm eye was a bit meaner than this IMO
I could not beleive they called Mobile Bay in MS.... OMG this guy is on Weatherunderground but was in Mobile Bay MS and showing the USS Alabama....
Come on folks at least get the city Right :o)

Taco :o)
1725. hahaguy
We had some intense weather today in St. Lucie. First time since Fay did my street flood.
Quoting NCHurricane2009:

Yeah...I am suprised though that the SS scale has central pressure as a reference value...I'd have just tossed those out if I had contributed to it...because its the wind (not the pressure value) that causes the tangible damage the SS scale is based on.

I guess the pressure values on the SS scale represent the statistical 90th percentile of storms in that category...



This is jus.t one of those storms I think it will surprise in the end
1728. acl8610
Quoting CaicosRetiredSailor:



Dayton International Speedway

In preparation for Isaac DIS welcomed 5,000 workers and 2,500 trucks from as far as Wyoming, Texas and Pennsylvania before embarking on their individual assignments. This FPL Connect pre-positioning at DIS marks the largest to date.

Yes that's Daytona International Speedway... I was just there, it was crazy. I have never seen anything like that before, being from NE Ohio originally.
Quoting TheHurricaneDundee:

I Just moved from Texas in 2010. I now live in NC. It's almost like the "I" stormms don't like me.(Ike, Irene...)

Yeah, the I storms sure made a name for themselves.
1730. HarryMc
Quoting KEEPEROFTHEGATE:


It has taken all day but the core has almost closed. Looking a lot more like a near-hurricane now.
Quoting WunderAlertBot:
JeffMasters has created a new entry.
Hey Dr.Masters watched you on TWC
Starting to feel a bit blustery here. Time to go take pictures of the house for insurance while I can still keep a camera level.
Hey so are we all gonna go switch over to the new entrie?
1734. hydrus
Inland flooding associated with the slow movement.
It look look like the upper level outflow is improving on the southeast and possibly the northwest sides, but dry air also seems to be wrapping into the COC. When one variable changes to support growth, another changes to hinder it.
Quoting taco2me61:
I could not beleive they called Mobile Bay in MS.... OMG this guy is on Weatherunderground but was in Mobile Bay MS and showing the USS Alabama....
Come on folks at least get the city Right :o)

Taco :o)



Taco r u for real. what the TWC has people here already or something?

sheri
Quoting Category5HitsFl:

I am thinking a strengthening upper level or lower level Cat 1 or 2 could be worse than a Cat weakening as it comes ashore, so I think its important to note this storm most likely will be strengthening as it hits land.


Funny, I thought the opposite was true, for example... although Katrina hit as a 3, it had the "built-up" water of a 5, since it had been a 5 previously.

Quoting Michfan:
I have a feeling that dry air slot is going to limit its RI. It needs to mix that out and fast.


Exactly

Isaac has made some progress, but that dry air could just as easily set him a step back.

Quoting oracle28:


Funny, I thought the opposite was true, for example... although Katrina hit as a 3, it had the "built-up" water of a 5, since it had been a 5 previously.


That's always been my understanding too. The other way around doesn't seem right.
Quoting TomballTXPride:

IIRC, someone mentioned on here earlier that Wilma had the lowest pressure as a TS before she became a hurricane. Not that this is Wilma. And bringing up that name still gives people chills down their spine. Either way, it's a pretty cool nugget.


she had the lowest pressure as a TS after being a hurricane.
Quoting Carnoustie:


she had the lowest pressure as a TS after being a hurricane.

Okay. Gotcha.
Quoting Elena85Vet:


Exactly

Isaac has made some progress, but that dry air could just as easily set him a step back.


My take is Isaac is going to cash out and head back to the FL panhandle.
Quoting Bluestorm5:
@weatherchannel

BREAKING NOW: President Obama directs @FEMA to give LA, MS & AL governors the resources they need


What about Florida I wonder?
1744. Roxanne
Quoting watchdog40:


What about Florida I wonder?


He sent FEMA days ago to Fl. I saw it on the local news here in Orlando
Quoting Adamcu81:
It look look like the upper level outflow is improving on the southeast and possibly the northwest sides, but dry air also seems to be wrapping into the COC. When one variable changes to support growth, another changes to hinder it.


The dry air thing has been going on for some time now. Isaac has been fighting it since he was an invest just west of Africa. I don't recall him ever being in an environment where dry air was not an issue. So that doesn't seem like a variable.
new blog :)
1747. Dakster
Quoting watchdog40:


What about Florida I wonder?


I haven't heard about any major damages in Florida that would require that...

FWIW, FEMA usually reimburses local governments for expenditures on natural disasters when declared. And this was declared ahead of time by Governor Rick Scott...

1748. Dakster
Quoting NCHurricane2009:

Is there a mandatory evac for NOLA? I haven't been checking any news sources all day here at work....(except for this blog)...


No mandatory evacuations that I have heard about either. Last statement I heard was that 900 people living outside the levees protection zone were asked to leave -- and if anyone else was thinking of leaving 'Now would be a good time.'

Again, look for official news releases from NOLA public officials and do not rely on this blog when making life or death decisions.

FWIW, I would be one of those people deciding to leave... and I do not live in NOLA and have never even been there. But seeing what happened with that 'K' storm I wouldn't chance it... (I am getting better at not mentioning the full name)
1749. Dakster
Quoting weatherh98:


Yes


Did they finally release one? CNN said it wasn't MANDATORY.
1750. Dakster
I found the wording:

-- New Orleans authorities expect Isaac to hit the city as a Category 1 hurricane early Wednesday, with tropical storm-force winds arriving shortly after midnight Monday, Mayor Mitch Landrieu said.

-- Landrieu did not issue an evacuation order for the city but urged people outside the city's protective levees to leave and told others, "If your plan is to go, now's the time to go."
Quoting NOLAGOLF:
No mandatory evacuation for New Orleans, but those who want to urged to leave now
http://www.nola.com/hurricane/index.ssf/2012/08/n o_mandatory_evacuation_for_ne.html


FB poll: all NOLA peeps are staying. Updates from the nearest station as long as the UPS keeps the phone up, which should get me through the storm. Houses are secure as they can get.

Cloud cover approaching 100%. F3 or F4 out, barometer 29.7 and falling.

Gave my sterno stove away when I thought I was leaving but everybody is invited over for cold canned mac & cheese and warm beer at the Fortress of Squalitude. Hope Patrap is getting a really nice tan somewhere.
Quoting KEEPEROFTHEGATE:


Look at that beautiful dry air. I see it closing up on water vapor but keep it comin'.
Quoting NCHurricane2009:


There are 981 mb cyclones frequently across the globe in non-tropical form...yet they are not as windy as a hurricane. Its about pressure gradient...not central pressure. If a storm is spread out...it has a lower pressure gradient (and lower wind) for same central pressure.

So its not a hurricane alone by merit of central pressure value. But yeah...he is really close. Maybe 979 mb will finally get him to cat 1...


I have been saying it will take 975mb to get this to a cat 1 most likely...
Quoting Dakster:


No mandatory evacuations that I have heard about either. Last statement I heard was that 900 people living outside the levees protection zone were asked to leave -- and if anyone else was thinking of leaving 'Now would be a good time.'

Again, look for official news releases from NOLA public officials and do not rely on this blog when making life or death decisions.

FWIW, I would be one of those people deciding to leave... and I do not live in NOLA and have never even been there. But seeing what happened with that 'K' storm I wouldn't chance it... (I am getting better at not mentioning the full name)
I would definitely leave!
Why We're Staying

A number of people have expressed surprise or dismay at the number of New Orleanians who are not leaving. There are several reasons for this, but primarily it is tied to former Mayor's Ray Nagin's poorly executed phased return policy.

Under this policy after Gustav (hardly a disaster for New Orleans) people were denied the ability to return and secure their homes from any damage on the theory that we couldn't possibly get by without full restoration of Cox Digital and a chance for the beer to get cold at Rouse's Supermarket.

We know how to get buy without power and with a boil water order. We're not going to grab a downed power line. We're not children, and the older of us have experience of this back to Betsy. Even the lead editorialist of the Times-Picayune (writing in a personal column) announced he would not leave for a mandatory evacuation order unless he thought it product and the phased return regime was eliminated.

It didn't help that FEMA went on national television promising to cover people's hotel bills, etc. during the whole phased return thing and then reneged on that promise.

We all watched anxiously during Gustav as the lake battered at the east side seawall of the Industrial Canal as a heroic few men secured a loose barge. Everything held.

We're not all throwing hurricane parties. We all learned that lesson from the people on the coast who died during Camille, thank you very much. People are hunkering down, well supplied (if they can afford it at the end of the month) in houses secured as best they can. We are following the directives of our local officials to shelter in place.

We are the survivors. We are the people who came home. We are not easily giving up what we have reclaimed.

The Tragedy of St. Bernard

-- Mark Folse
ToulouseStreet.net
oops... lol
1757. 2ifbyC
Quoting WetBankGuy:
Why We're Staying

Mark Folse


You, sir, are my hero!
Nice here in Denham Springs La. this morning. Enjoying the breeze and a cup of coffee. 24 hours from now, likely a different story.
yep