Isaac remains disorganized

By: Dr. Jeff Masters , 8:29 PM GMT on August 23, 2012

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Tropical Storm Isaac has strengthened slightly, data from the hurricane hunters show, but the storm remains disorganized and difficult to forecast. If you have to make decisions based upon what Isaac will do, I highly recommend that you wait until at least Friday morning to make a decision, if at all possible, as the forecasts then should be of significantly higher accuracy. Isaac continues to have a large area of light winds about 50 miles across near its center. This makes the storm subject to reformations of the center closer to areas of heavy thunderstorms that form, resulting in semi-random course changes. Until Isaac consolidates, the lack of a well-defined center will make forecasts of the storm's behavior less accurate than usual. An Air Force Reserve hurricane hunter aircraft is in Isaac this afternoon, and has found that surface tropical storm-force winds on the east side of the storm, south of Puerto Rico, have undergone a modest expansion. These winds were mostly in the 40 mph range, with a few areas of 45 mph winds. The surface pressure remained fairly high, at 1004 mb. Infrared and visible satellite loops show that Isaac has fairly symmetric circular cloud pattern, with developing spiral bands that are contracting towards the center, which suggests intensification. However, the storm has a very clumpy appearance, and is a long way from being a hurricane. Given the storm's continued reluctance to organize, Isaac is unlikely to reach hurricane strength before encountering Haiti and Cuba. An analysis of upper level winds from the University of Wisconsin CIMSS shows an upper-level outflow channel well-established to the north, and an intermittent outflow channel to the south. Radar imagery from Puerto Rico shows some weak low-level spiral bands that haven't changed much in intensity or organization this afternoon. NOAA buoy 42060 reported 1-minute mean winds of 35 mph and a wind gust of 40 early this afternoon. At St. Thomas in the Virgin Islands, wind gusts up to 45 mph were observed early this afternoon. Isaac's rains caused major flooding last night in Trinidad and Tobago, the southernmost islands of the Lesser Antilles chain, according to the Trinidad Express. Isaac's rains have not been heavy enough today to cause flooding problems on other islands.


Figure 1. True-color MODIS image of Isaac taken at 1:40 pm EDT August 23, 2012. Image credit: NASA.

Latest model runs for Isaac
The latest set of 12Z (8 am EDT) model runs have shifted to the west compared to the previous set of runs. The models continue to show a west-northwestward track to a point on the south coast of Hispaniola, then across eastern Cuba and into the Florida Straits between Florida and Cuba. A trough of low pressure is then expected to pull Isaac to the northwest and then north, towards the Florida Panhandle. The big news in this model cycle is that both of our top models--the GFS and ECMWF--predict that 5 - 6 days from now, the trough of low pressure pulling Isaac to the north may not be strong enough to finish the job. These models predict that the trough will lift out and a ridge of high pressure will build in, forcing Isaac more to the west. The GFS predicts this will occur after Isaac makes landfall in the Florida Panhandle, resulting in Isaac moving slowly to the west over land, from Georgia to Alabama. The ECMWF predicts the westward motion will happen while Isaac is in the northern Gulf of Mexico, resulting in an eventual landfall near the Louisiana/Texas border on Thursday. There are some huge issues to resolve to make an accurate long-range track forecast for Isaac. Where will its center consolidate? How will the interaction with the mountains of Hispaniola and Cuba will affect it? Where will Isaac pop off the coast of Cuba? Hopefully, the data being collected by the NOAA jet this afternoon will give us a more unified set of model forecasts early Friday morning. For now, pay attention to the cone of uncertainty. If you're in the cone, you might get hit.



Figure 2. Predicted 5-day rainfall total ending at 8 am EDT Tuesday August 28 from Tropical Storm Isaac. Graphics were generated from the 12Z (8 am EDT) August 23, 2012 run of the HWRF model (top) and GFDL model (bottom). The heaviest rainfall is expected to occur in a 50 - 80 wide wide swath along and to the right of where the center tracks. Amounts in excess of 8 inches (yellow colors) are predicted for portions of the Dominican Republic and Haiti from the HWRF model, but not the GFDL model. Given the current disorganization of Isaac, these rainfall amounts are probably at least 20% too high. Image credit: Morris Bender, NOAA/Geophysical Fluid Dynamics Laboratory.

Jeff Masters

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4524. nola70119
12:59 PM GMT on August 25, 2012
Quoting weatherman12345:
interesting to note that the gfs ensembles show paint a much more eatern picture over south florida...


What site are you looking at?
Member Since: June 16, 2006 Posts: 0 Comments: 1565
4523. Dakster
10:32 PM GMT on August 24, 2012
Quoting beachman42:
The new GFS track issued at 1pm now shows it hugging the coast all the way up.

The Ew will up date its track around 3:30 pm.


Who is the Ew?
Member Since: March 10, 2006 Posts: 0 Comments: 10571
4522. beachman42
5:41 PM GMT on August 24, 2012
The new GFS track issued at 1pm now shows it hugging the coast all the way up.

The Ew will up date its track around 3:30 pm.
Member Since: June 3, 2005 Posts: 1 Comments: 17
4521. AussieStorm
3:50 PM GMT on August 24, 2012
Tropical Storm Isaac is having an impact on two more cruise ships sailing out of Florida.

Royal Caribbean says the 2,350-passenger Majesty of the Seas and 2,390-passenger Monarch of the Seas will not call this weekend at CocoCay, the line's private island in the Bahamas. The ships are setting sail today from Florida's Port Canaveral and Port of Miami, respectively.

The announcement brings to five the number of vessels affected by Isaac. Industry giant Carnival's 2,974-passenger Carnival Valor skipped a call Thursday in Curacao to stay ahead of the storm. The ship instead is today visiting Nassau in the Bahamas. Another Carnival ship, the 2,978-passenger Carnival Liberty, also is visiting Nassau today after skipping a call Thursday in Grand Turk.

Also on an altered course this week due to Isaac is Royal Caribbean's 5,400-passenger Allure of the Seas, which departed from Fort Lauderdale on Sunday. The world's largest cruise ship has sailed for the Western Caribbean instead of heading to the Eastern Caribbean as planned. It's visiting Falmouth, Jamaica and Cozumel, Mexico instead of St. Thomas and St. Maarten.

As of 11 a.m. ET, Isaac was 165 miles south-southwest of Santo Domingo, Dominican Republic and moving to the west-northwest at 14 miles per hour. The storm has maximum sustained winds of 60 miles per hour.
Member Since: September 30, 2007 Posts: 9 Comments: 15962
4520. PedleyCA
3:47 PM GMT on August 24, 2012
NEW BLOG
Member Since: February 29, 2012 Posts: 0 Comments: 6000
4519. AussieStorm
3:43 PM GMT on August 24, 2012
Quoting kwgirl:
Can someone tell me what the F5 keys is for. I never use them, leaving key strokes behind with the DOS system.

F5 = Page Refresh.
Member Since: September 30, 2007 Posts: 9 Comments: 15962
4517. Grothar
3:38 PM GMT on August 24, 2012
Quoting kwgirl:
Can someone tell me what the F5 keys is for. I never use them, leaving key strokes behind with the DOS system.


It is the button to refresh a page. Some bloggers (not mentioning who) hit the F8 button to switch sites and hit the F5 button every second so they can be the first to post the NHC information. Not that I have ever done that myself.:)
Member Since: July 17, 2009 Posts: 71 Comments: 26847
4516. kwgirl
3:36 PM GMT on August 24, 2012
Quoting interstatelover7165:
NHC Y U NO ALREADY UPDATE
They are checking with the Governor and the GOP. I think their cone has changed.
Member Since: March 28, 2008 Posts: 0 Comments: 1532
4515. Grothar
3:36 PM GMT on August 24, 2012
The lastest


Member Since: July 17, 2009 Posts: 71 Comments: 26847
4514. Grothar
3:34 PM GMT on August 24, 2012
Member Since: July 17, 2009 Posts: 71 Comments: 26847
4513. kwgirl
3:33 PM GMT on August 24, 2012
Quoting Grothar:
Get ready


Can someone tell me what the F5 keys is for. I never use them, leaving key strokes behind with the DOS system.
Member Since: March 28, 2008 Posts: 0 Comments: 1532
4512. auburn (Mod)
3:27 PM GMT on August 24, 2012
Quoting AussieStorm:

I don't know where you heard that from but this loop shows differently.


Like I said..I am just a parrot...I depend on you guys,just thought it was worth a mention.
Member Since: August 27, 2006 Posts: 547 Comments: 50724
4511. AussieStorm
3:24 PM GMT on August 24, 2012
Quoting auburn:
I am hearing that the ECMWF model hints that Isaac could stall out over the Tennessee Valley for several days after landfall.(I am just a parrot..repeating what I hear)

I don't know where you heard that from but this loop shows differently.
Member Since: September 30, 2007 Posts: 9 Comments: 15962
4510. RTSplayer
3:19 PM GMT on August 24, 2012
I'll continue going with the western edge of the cone until I see real evidence of the NHC fix being right.




The 1445 frame admittedly gives me pause because it looks like something shifted during that time, but I'm still not convinced it's as far as 16.3N.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
4509. auburn (Mod)
3:19 PM GMT on August 24, 2012
I am hearing that the ECMWF model hints that Isaac could stall out over the Tennessee Valley for several days after landfall.(I am just a parrot..repeating what I hear)
Member Since: August 27, 2006 Posts: 547 Comments: 50724
4508. AussieStorm
3:19 PM GMT on August 24, 2012
Quoting sunlinepr:
Real COC coordinates?


Sorry but I see a loop of Typhoon Bolaven. That's the problem posting anything from CIMISS.
I use sniping tool on win 7 and upload the image to imageshack.us .
Member Since: September 30, 2007 Posts: 9 Comments: 15962
4507. Grothar
3:18 PM GMT on August 24, 2012
The FIM8 and the FIM9

Member Since: July 17, 2009 Posts: 71 Comments: 26847
4506. sunlinepr
3:12 PM GMT on August 24, 2012
Real COC coordinates?

Member Since: August 2, 2010 Posts: 21 Comments: 9874
4505. presslord
3:12 PM GMT on August 24, 2012
Quoting mcluvincane:
NHC not to enthusiastic about a strong storm in the gulf.... might just be a rain maker after all




That's heresy around here, you know...but I think you may well be right...(forgot who I was for a moment there)
Member Since: August 13, 2007 Posts: 0 Comments: 10492
4504. Portlight
3:09 PM GMT on August 24, 2012
:-)
Member Since: January 7, 2009 Posts: 127 Comments: 412
4503. FLWeatherFreak91
3:08 PM GMT on August 24, 2012
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
509 AM EDT FRI AUG 24 2012

FLZ039-042-043-048>052-055>057-060>062-065-242115 -
LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSB OROUGH-POLK-
MANATEE-HARDEE-HIGHLANDS-SARASOTA-DESOTO-CHARLOTT E-LEE-
509 AM EDT FRI AUG 24 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

...POTENTIAL TROPICAL IMPACTS...
TROPICAL STORM ISAAC...CURRENTLY LOCATED SOUTH OF THE DOMINICAN
REPUBLIC EARLY THIS MORNING...IS FORECAST BY THE NATIONAL
HURRICANE CENTER TO MOVE ON A GENERAL WEST-NORTHWEST TRACK
THROUGH THE END OF THIS WEEK. ISAAC IS THEN EXPECTED TO TURN
NORTHWEST...MOVING IN THE GENERAL DIRECTION OF FLORIDA DURING THE
WEEKEND AND THERE IS A POTENTIAL FOR ISAAC TO IMPACT THE FLORIDA
PENINSULA EARLY NEXT WEEK
. THERE IS SOME UNCERTAINTY WITH REGARDS
TO THE EXACT TRACK AND INTENSITY OF ISAAC AND AS TO WHETHER OR NOT
ISAAC WILL HAVE DIRECT IMPACT ON WEST CENTRAL AND SOUTHWEST
FLORIDA....HOWEVER ALL INTERESTS ARE ENCOURAGED TO CONSULT THE
LATEST GUIDANCE AND INFORMATION FROM THE NATIONAL HURRICANE CENTER
CONCERNING THE POSSIBLE EFFECTS OF TROPICAL STORM ISAAC.

...THUNDERSTORM IMPACT...
MOISTURE BEGINS TO RETURN WITH SCATTERED SHOWERS AND STORMS FOR
THE WEEKEND...BUT BECOMING NUMEROUS ACROSS THE SOUTH. NUMEROUS
SHOWERS AND ISOLATED THUNDERSTORMS SPREAD ACROSS THE ENTIRE AREA
MONDAY. SHOWER AND STORMS BEGIN TO TAPER BACK TO SCATTERED
TUESDAY. A FEW OF THESE STORMS MAY BE STRONG WITH GUSTY
WINDS...BUT THE MAIN THREAT WILL CONTINUE TO BE LOCALLY HEAVY
RAINFALL AND OCCASIONAL LIGHTNING STRIKES.

...TORNADO IMPACT...
DEPENDING UPON THE TRACK ISAAC TAKES OUTER BANDS FROM THE STORMS
COULD GRAZE SOUTHWEST AND WEST-CENTRAL FLORIDA MONDAY AND RESULT
IN THE THREAT OF TORNADOES.

...WIND AND SEA IMPACT...
WINDS OVER THE ADJACENT GULF WATERS WILL BE ON THE INCREASE DURING
THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK DUE TO HIGH
PRESSURE TO THE NORTH AND TROPICAL CYCLONE ISAAC TO THE SOUTHEAST.
THE INCREASING WINDS WILL LEAD TO BUILDING SEAS WHICH WILL PRODUCE
VERY ROUGH BOATING CONDITIONS FOR SMALL CRAFT OPERATORS. ALL
MARINERS SHOULD CONTINUE TO MONITOR THE PROGRESS OF TROPICAL
CYCLONE ISAAC THROUGH THE REMAINDER OF THE WEEK AND INTO THE
UPCOMING WEEKEND.
Member Since: December 1, 2006 Posts: 2 Comments: 3631
4502. sunlinepr
3:06 PM GMT on August 24, 2012
Member Since: August 2, 2010 Posts: 21 Comments: 9874
4501. sunlinepr
3:05 PM GMT on August 24, 2012
Member Since: August 2, 2010 Posts: 21 Comments: 9874
4500. sunlinepr
3:05 PM GMT on August 24, 2012
Really???

Member Since: August 2, 2010 Posts: 21 Comments: 9874
4499. sunlinepr
3:04 PM GMT on August 24, 2012
How powerfull that ULL has been in all this processs... It ate Joyce turning into a Ex-tropical system and is responsible of keeping Isaac moving WSW... making model forecast unpredictable...

Member Since: August 2, 2010 Posts: 21 Comments: 9874
4498. southfla
3:02 PM GMT on August 24, 2012
Quoting guygee:

Firstly, expensive compared to what? Maintaining the International Space
Station? War?
If we could improve our forecasts, what would be the savings in lives and property?
Also, if we had more buoys, we would realize economies of scale that would reduce cost per unit. Seems like a good investment to me. Just sayin'


I would agree it is a good investment, however government funding -- for all countries -- has been cut for observational marine meteorology and oceanography. Ship time is typically $5k to $40k a day, depending upon the size of the vessel. Then there is equipment, personnel, etc. Maybe you are right that the total is not as costly as a space station. The key is in convincing the stake holders that it is worth the expense.
Member Since: May 19, 2009 Posts: 0 Comments: 252
4497. CloudGatherer
3:02 PM GMT on August 24, 2012
Quoting RTSplayer:


They are still looking at the optical illusion at or above 16N.
RECONNAISSANCE AIRCRAFT DATA AND SATELLITE IMAGERY INDICATE THAT ISAAC HAS BECOME BETTER ORGANIZED DURING THE PAST SEVERAL HOURS. WHILE THE CIRCULATION CENTER REMAINS ELONGATED EAST-TO-WEST WITH MULTIPLE EMBEDDED VORTICITY MAXIMA...THE LARGE CENTRAL AREA OF LIGHT WINDS HAS SHRUNK AS THE STRONGEST WINDS MOVE CLOSER TO THE CENTER.

The fix puts the storm at 16.3N 70.8W. The NHC states the obvious - which is that Isaac has slowly been tightening up, pulling its winds around its sprawling and structurally complicated center. I don't think it's unreasonable, at this point, to suggest that the apparent feature on the visible satellite loops which shows a clearing right above the reported center of circulation, and which is backed up by the banding to the south (and to a lesser extent, east and west) on the 37ghz, might be evidence of a tightened, better defined core. It won't be an eye until it manages to form walls and consolidate its vortices. But it's something.
Member Since: August 18, 2009 Posts: 0 Comments: 460
4496. StormHype
3:02 PM GMT on August 24, 2012
Quoting RTSplayer:


They are still looking at the optical illusion at or above 16N.


NHC falls for 'optical illusion'? lol

You need to stick the "RTS playing" and leave the positioning to the pros. Obviously, they know something you don't or are ignoring. Looking at the last recon plots on google earth and extrapolating for elapsed time seems to put sense into their position.
Member Since: May 31, 2007 Posts: 0 Comments: 1208
4495. Neapolitan
3:01 PM GMT on August 24, 2012
Quoting oracle28:
Question:

What time does the XTRP model update?
Z-z-z-z-z-z-z-z-z-z.....

I will buy you this, if you'd like.

;-)
Member Since: November 8, 2009 Posts: 4 Comments: 13603
4494. JasonRE
3:01 PM GMT on August 24, 2012
So Louisiana is no longer threatened by this storm, correct? I know it still has land to cross and the GOM to fuel it, but as I look at the models compared to last night and the intensification of this storm, it should be on a more Northward track to the Gulf Coast, right?

Also, will MS and or LA feel the effects of this storm if it's a 2 when it makes landfall or is that too far away?
Member Since: August 6, 2012 Posts: 0 Comments: 122
4493. kwgirl
3:01 PM GMT on August 24, 2012
Quoting Torgen:
I'm on pain meds for my back, but guess I need to get up and start stacking stuff in the garage so I can move the patio furniture/birdbath in. Looks like Romney should have had his party in Mickeyville. Most of the convention-goers are staying in hotels in Pinellas/near the beach. Evacuation (if it comes) is gonna be "fun."
Sometimes it is easier to tie the chairs where they are if you have something solid. I usually tied my garbage cans to the fence. Might save some on your back.
Member Since: March 28, 2008 Posts: 0 Comments: 1532
4492. mcluvincane
3:01 PM GMT on August 24, 2012
NHC not to enthusiastic about a strong storm in the gulf.... might just be a rain maker after all
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4491. Gino99
3:01 PM GMT on August 24, 2012
Phew.. I expected worse than 60mph. Lets hope that Isaac doesn't reach Hurricane status before hitting Haiti.. Most of the people over there are still in tents :\
Member Since: August 29, 2008 Posts: 0 Comments: 24
4490. sunlinepr
3:00 PM GMT on August 24, 2012
Member Since: August 2, 2010 Posts: 21 Comments: 9874
4489. WxLogic
3:00 PM GMT on August 24, 2012
Is moving NW... but NHC pretty much want to see consistency and validation from HH before officially stating NW:

ISAAC APPEARS TO HAVE ACQUIRED A STRONGER
NORTHWARD COMPONENT OF MOTION...AND THE INITIAL MOTION IS A
SOMEWHAT UNCERTAIN 295/12.

I would lean with GFS since it has shown better consistency and ECMWF:

AFTER 72 HR...THE SPREAD OF THE TRACK
GUIDANCE INCREASES DUE TO MODEL DISAGREEMENT ON THE EVOLUTION OF A
TROUGH OVER THE EASTERN UNITED STATES. THE ECMWF KEEPS MORE RIDGE
BETWEEN ISAAC AND THE TROUGH...WHICH RESULTS IN A NORTHWESTWARD
MOTION THROUGH DAY 5. THE GFS HAS A STRONGER TROUGH...WHICH
RESULTS IN A MORE NORTHWARD MOTION. THE GUIDANCE ENVELOPE HAS
SHIFTED A LITTLE EASTWARD AFTER 72 HR...AND THUS THE LATTER PORTION
OF THE NEW FORECAST TRACK IS ALSO ADJUSTED EASTWARD.
Member Since: August 14, 2008 Posts: 4 Comments: 5028
4488. noraneinsite
3:00 PM GMT on August 24, 2012
I dont know about the ants but my boxers are riding alot higher today than they were yesterday..I live on the Texas coast...should I start boarding up!
Member Since: August 17, 2011 Posts: 0 Comments: 11
4487. oracle28
2:59 PM GMT on August 24, 2012
Question:

What time does the XTRP model update?
Member Since: July 25, 2008 Posts: 0 Comments: 596
4486. 7544
2:59 PM GMT on August 24, 2012
Quoting Seflhurricane:
INTERESTS THE REMAINDER OF CUBA...THE REMAINDER OF THE BAHAMAS...
SOUTH FLORIDA...AND THE FLORIDA KEYS SHOULD MONITOR THE PROGRESS OF
ISAAC. WATCHES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE FLORIDA
KEYS LATER TODAY AND ARE ALSO POSSIBLE FOR PORTIONS OF THE SOUTHERN
FLORIDA PENINSULA.


well i got it half right lol
Member Since: May 6, 2007 Posts: 0 Comments: 6871
4485. floridaboy14
2:59 PM GMT on August 24, 2012
16.3N? what a joke. center is at 15.9N. yes it is moving wnw not NW
Member Since: July 25, 2011 Posts: 0 Comments: 1102
4484. Maineweatherguy20023
2:59 PM GMT on August 24, 2012
Quoting interstatelover7165:

000
WTNT44 KNHC 241455
TCDAT4

TROPICAL STORM ISAAC DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 AM EDT FRI AUG 24 2012

RECONNAISSANCE AIRCRAFT DATA AND SATELLITE IMAGERY INDICATE THAT
ISAAC HAS BECOME BETTER ORGANIZED DURING THE PAST SEVERAL HOURS.
WHILE THE CIRCULATION CENTER REMAINS ELONGATED EAST-TO-WEST WITH
MULTIPLE EMBEDDED VORTICITY MAXIMA...THE LARGE CENTRAL AREA OF
LIGHT WINDS HAS SHRUNK AS THE STRONGEST WINDS MOVE CLOSER TO THE
CENTER. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED
66 KT FLIGHT-LEVEL WINDS AT 850 MB NORTHEAST OF THE CENTER...ALONG
WITH SFMR BIAS-CORRECTED WIND ESTIMATES NEAR 50 KT. BASED ON THESE
DATA...THE INITIAL INTENSITY IS INCREASED TO 50 KT.

THE 12Z POSITION USED A MEAN CENTER...WHICH RESULTED IN A SOUTHWARD
ADJUSTMENT. SINCE THEN...ISAAC APPEARS TO HAVE ACQUIRED A STRONGER
NORTHWARD COMPONENT OF MOTION...AND THE INITIAL MOTION IS A
SOMEWHAT UNCERTAIN 295/12. THE TRACK MODEL GUIDANCE IS IN GOOD
AGREEMENT THAT ISAAC SHOULD MOVED NORTHWESTWARD FOR THE NEXT 72
HR...STEERED BY THE SUBTROPICAL RIDGE OVER THE WESTERN ATLANTIC
TOWARD A WEAKNESS IN THE RIDGE OVER THE SOUTHEASTERN UNITED STATES.
THIS PART OF THE NEW FORECAST TRACK IS SHIFTED A LITTLE TO THE LEFT
OF THE PREVIOUS TRACK BASED ON THE INITIAL POSITION...AND LIES NEAR
THE CONSENSUS MODELS. AFTER 72 HR...THE SPREAD OF THE TRACK
GUIDANCE INCREASES DUE TO MODEL DISAGREEMENT ON THE EVOLUTION OF A
TROUGH OVER THE EASTERN UNITED STATES. THE ECMWF KEEPS MORE RIDGE
BETWEEN ISAAC AND THE TROUGH...WHICH RESULTS IN A NORTHWESTWARD
MOTION THROUGH DAY 5. THE GFS HAS A STRONGER TROUGH...WHICH
RESULTS IN A MORE NORTHWARD MOTION. THE GUIDANCE ENVELOPE HAS
SHIFTED A LITTLE EASTWARD AFTER 72 HR...AND THUS THE LATTER PORTION
OF THE NEW FORECAST TRACK IS ALSO ADJUSTED EASTWARD.

WHILE THE ORGANIZATION HAS IMPROVED...THE STRUCTURE OF ISAAC STILL
DOES NOT FAVOR RAPID INTENSIFICATION DESPITE A VERY FAVORABLE
UPPER-LEVEL WIND PATTERN. THE EARLY PART OF THE INTENSITY FORECAST
SHOWS A LITTLE MORE STRENGTHENING THAN EARLIER...AND IT IS POSSIBLE
THAT ISAAC COULD BE NEAR HURRICANE STRENGTH WHEN IT REACHES
HISPANIOLA. LAND INTERACTION WILL LIMIT THE INTENSITY FROM 24-48
HR...AND THIS PART OF THE FORECAST MAY NEED SOME ADJUSTMENT AFTER
IT IS SEEN WHAT STRUCTURE ISAAC HAS AFTER CROSSING HISPANIOLA.
ISAAC SHOULD STRENGTHEN OVER THE GULF OF MEXICO...WITH THE FORECAST
SHOWING THE CYCLONE BECOMING A HURRICANE BEFORE REACHING THE
NORTHERN GULF COAST.

IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK DUE TO THE
UNCERTAINTIES IN THE FORECAST AND THE FACT THAT ISAAC HAS A LARGE
AREA OF TROPICAL STORM FORCE WINDS ASSOCIATED WITH IT.


FORECAST POSITIONS AND MAX WINDS

INIT 24/1500Z 16.3N 70.8W 50 KT 60 MPH
12H 25/0000Z 17.4N 72.6W 55 KT 65 MPH
24H 25/1200Z 19.2N 75.1W 55 KT 65 MPH
36H 26/0000Z 20.9N 77.6W 50 KT 60 MPH...INLAND
48H 26/1200Z 22.3N 79.5W 45 KT 50 MPH...INLAND
72H 27/1200Z 25.0N 83.0W 55 KT 65 MPH...OVER WATER
96H 28/1200Z 28.0N 85.5W 65 KT 75 MPH
120H 29/1200Z 31.0N 86.5W 70 KT 80 MPH...INLAND

$$
FORECASTER BEVEN

Cant go from Hispaniola to LA in 3 days
Member Since: August 1, 2012 Posts: 0 Comments: 269
4483. WunderAlertBot (Admin)
2:58 PM GMT on August 24, 2012
JeffMasters has created a new entry.
4482. MAweatherboy1
2:58 PM GMT on August 24, 2012
A rather conservative intensity forecast at 11AM.
Member Since: February 11, 2012 Posts: 84 Comments: 7939
4481. GeorgiaStormz
2:58 PM GMT on August 24, 2012
RECONNAISSANCE AIRCRAFT DATA AND SATELLITE IMAGERY INDICATE THAT
ISAAC HAS BECOME BETTER ORGANIZED DURING THE PAST SEVERAL HOURS.
WHILE THE CIRCULATION CENTER REMAINS ELONGATED EAST-TO-WEST WITH
MULTIPLE EMBEDDED VORTICITY MAXIMA...THE LARGE CENTRAL AREA OF
LIGHT WINDS HAS SHRUNK AS THE STRONGEST WINDS MOVE CLOSER TO THE
CENTER.
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED
66 KT FLIGHT-LEVEL WINDS AT 850 MB NORTHEAST OF THE CENTER...ALONG
WITH SFMR BIAS-CORRECTED WIND ESTIMATES NEAR 50 KT. BASED ON THESE
DATA...THE INITIAL INTENSITY IS INCREASED TO 50 KT.


Storms without true centers, and multiple voriticity maximas and with mean centers do not have eyes
Member Since: February 11, 2012 Posts: 0 Comments: 9737
4480. ncstorm
2:58 PM GMT on August 24, 2012
Henry Margusity..

Isaac Track Window
Aug 24, 2012; 7:18 AM ET

Commentary

1. Isaac appears to be going through an intensification stage this morning based on the satellite and radar data. When you see the outflow showing the gravity waves on the satellite image, that usually means good venting aloft and intensification of the storm. Just an observation I have seen over the years.

2. Below is a satellite image showing the water vapor channel. Notice the trough over Colorado. I believe that trough is the key to the track of Isaac as it comes off Cuba. The other track map shows the two possible tracks Isaac can take. If the trough is weaker and goes north, Isaac will end up in the eastern Gulf of Mexico. If the trough is stronger and goes east, it will bring Isaac up the East Coast of Florida which I have been in the camp for happening all week. I know none of the models show that possibility, but I am going to hold on to the track until I see otherwise. Yes, I know I am going out on a limb and against all models, but it just seems to me that a track into the Gulf seems odd given the trough in the Rockies and the trough associated with Joyce. I believe that Isaac will try to squeeze between the two up east of Florida.

3. Once Isaac does clear Cuba, the storm will be in position to go through another rapid intensification period. It may go to a Category 3 hurricane before making landfall. Isaac should not be taken lightly because in my mind, the storm has a lot of potential to do a considerable amount of damage and flooding once it impacts the U.S.
Member Since: August 19, 2006 Posts: 13 Comments: 16039
4479. tkdaime
2:57 PM GMT on August 24, 2012
People from south Florida to north Florida have to worry about Isaac dropping tornadoes and lots of rain and how fast will Isaac move out pretty scary here in s Florida now any comments anybody
Member Since: August 4, 2012 Posts: 0 Comments: 100
4478. moonlightcowboy
2:57 PM GMT on August 24, 2012
Quoting CloudGatherer:
Isaac is apparently trying to tell us how much he loves us.

Never seen a SCAT pass look like a valentine before.



Thank you for that - verifies what I was saying earlier.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
4477. EcoLogic
2:57 PM GMT on August 24, 2012
000
WTNT34 KNHC 241454
TCPAT4

BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 AM EDT FRI AUG 24 2012

...ISSAC STRENGTHENS A LITTLE MORE AS IT MOVES WEST-NORTHWESTWARD
TOWARD THE SOUTHERN COAST OF HISPANIOLA...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.3N 70.8W
ABOUT 165 MI...265 KM SSW OF SANTO DOMINGO DOMINICAN REPUBLIC
ABOUT 185 MI...300 KM SSE OF PORT AU PRINCE HAITI
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF CUBA HAS ISSUED A TROPICAL STORM WARNING FOR THE
CUBAN PROVINCES OF CIEGO DE AVILA...SANCTI SPIRITUS...AND VILLA
CLARA.

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A TROPICAL STORM WARNING
FOR THE CENTRAL BAHAMAS INCLUDING CAT ISLAND...THE EXUMAS...LONG
ISLAND...RUM CAY...AND SAN SALVADOR.

THE GOVERNMENT OF CUBA HAS ISSUED A TROPICAL STORM WATCH FOR THE
CUBAN PROVINCES OF MATANZAS AND CIENFUEGOS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WATCH IS IN EFFECT FOR...
* HAITI

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* DOMINICAN REPUBLIC
* HAITI
* CUBAN PROVINCES OF CIEGO DE AVILA...SANCTI SPIRITUS...VILLA
CLARA...CAMAGUEY...LAS TUNAS...GRANMA...HOLGUIN...SANTIAGO DE
CUBA...AND GUANTANAMO
* THE CENTRAL BAHAMAS INCLUDING CAT ISLAND...THE EXUMAS...LONG
ISLAND...RUM CAY...AND SAN SALVADOR
* SOUTHEASTERN BAHAMAS INCLUDING THE ACKLINS...CROOKED ISLAND...LONG
CAY...THE INAGUAS...MAYAGUANA...AND THE RAGGED ISLANDS
* TURKS AND CAICOS ISLANDS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* CUBAN PROVINCES OF MATANZAS AND CIENFUEGOS
* ANDROS ISLAND
* JAMAICA

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA...IN THIS CASE WITHIN THE NEXT 24 TO 36 HOURS.

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.

INTERESTS THE REMAINDER OF CUBA...THE REMAINDER OF THE BAHAMAS...
SOUTH FLORIDA...AND THE FLORIDA KEYS SHOULD MONITOR THE PROGRESS OF
ISAAC. WATCHES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE FLORIDA
KEYS LATER TODAY AND ARE ALSO POSSIBLE FOR PORTIONS OF THE SOUTHERN
FLORIDA PENINSULA.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 16.3 NORTH...LONGITUDE 70.8 WEST. ISAAC IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 14 MPH. A TURN TOWARD THE
NORTHWEST IS EXPECTED LATER TODAY...WITH A CONTINUED NORTHWESTWARD
MOTION EXPECTED TROUGH SUNDAY. ON THE FORECAST TRACK...THE CENTER
OF ISAAC WILL APPROACH THE SOUTHERN COAST OF HISPANIOLA TODAY...
PASS NEAR OR OVER HAITI TONIGHT...AND MOVE NEAR OR OVER EASTERN AND
CENTRAL CUBA SATURDAY AND SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NOW NEAR 60 MPH...95 KM/H...WITH HIGHER
GUSTS. SOME ADDITIONAL STRENGTHENING IS POSSIBLE BEFORE THE CENTER
REACHES THE COAST OF HISPANIOLA TONIGHT.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB...29.53 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...TOTAL RAINFALL ACCUMULATIONS OF 8 TO 12 INCHES...WITH
MAXIMUM AMOUNTS OF 20 INCHES...ARE POSSIBLE OVER HISPANIOLA. THESE
RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.
TOTAL RAIN ACCUMULATIONS OF 4 TO 8 INCHES...WITH MAXIMUM AMOUNTS OF
12 INCHES...ARE POSSIBLE ACROSS EASTERN CUBA AND JAMAICA. TOTAL
RAIN ACCUMULATIONS OF 2 TO 4 INCHES...WITH MAXIMUM AMOUNTS OF 6
INCHES ARE EXPECTED OVER PUERTO RICO AND THE VIRGIN ISLANDS. TOTAL
RAIN ACCUMULATIONS OF 2 TO 4 INCHES ARE POSSIBLE OVER THE
SOUTHEASTERN BAHAMAS.

WIND...TROPICAL STORM CONDITIONS ARE EXPECTED OVER PORTIONS OF THE
DOMINICAN REPUBLIC AND HAITI TODAY...WITH HURRICANE CONDITIONS
POSSIBLE. TROPICAL STORM CONDITIONS ARE EXPECTED OVER THE
SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS LATER TODAY
AND TONIGHT...AND ARE EXPECTED OVER THE CENTRAL BAHAMAS BY SATURDAY
OR SATURDAY NIGHT. TROPICAL STORM CONDITIONS ARE EXPECTED OVER
EASTERN CUBA BY TONIGHT AND OVER CENTRAL CUBA BY SATURDAY OR
SATURDAY NIGHT. TROPICAL STORM CONDITIONS COULD REACH NORTHWESTERN
CUBA AND ANDROS ISLAND BY SATURDAY NIGHT.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1
TO 3 FEET ABOVE NORMAL TIDE LEVELS IN AREAS OF ONSHORE WINDS IN THE
TROPICAL STORM WARNING AREA. NEAR THE COAST...THE SURGE WILL BE
ACCOMPANIED BY DANGEROUS WAVES.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT THE
VIRGIN ISLANDS...PUERTO RICO...HISPANIOLA...THE SOUTHEASTERN AND
CENTRAL BAHAMAS...THE TURKS AND CAICOS...AND EASTERN AND CENTRAL
CUBA DURING THE NEXT COUPLE OF DAYS. PLEASE CONSULT PRODUCTS FROM
YOUR LOCAL WEATHER OFFICE FOR MORE INFORMATION.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM EDT.
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BEVEN
Member Since: June 29, 2010 Posts: 0 Comments: 53
4476. kwgirl
2:57 PM GMT on August 24, 2012
Quoting BahaHurican:
Doesn't want the general population to associate "Tampa" with "terrible storm"...

:o(
No what is really happening is that the Skeletor thinks he is god and assures them the science is wrong. Remember that is the Mantra of the GOP. It will be on his head if they continue getting people into Tamps. IF I lived in Tampa, I would be heading out now, so as not to get caught in the 1 million people living in the evacuation zone. That convention center is going to be underwater.
Member Since: March 28, 2008 Posts: 0 Comments: 1532
4475. BahaHurican
2:57 PM GMT on August 24, 2012
Quoting CaribBoy:
WTF ONLY FISH STORMS ON THE GFS! Well season is over for the Lesser Antilles.
How did u enjoy your TS experience?

LOL
Member Since: October 25, 2005 Posts: 19 Comments: 22563
4474. Articuno
2:57 PM GMT on August 24, 2012
60 mph it is.


If this trend continues we may likely see a cat 2 or higher in cuba and the keys.

Once again:

Member Since: October 22, 2011 Posts: 0 Comments: 2543

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.