Isaac slamming Gulf Coast with damaging floods, tornadoes

By: Dr. Jeff Masters , 4:44 PM GMT on August 30, 2012

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Slow-moving Tropical Storm Isaac continues to hammer coastal Louisiana, Mississippi, Alabama, and Florida's Panhandle with tornadoes, torrential rains, high winds, and a damaging storm surge. Over the past 24 hours, destructive tornadoes have touched down in Biloxi and Pascagoula, Mississippi, and one person was killed by a tree falling on a car in Pearl River County, Mississippi. A major flood event is occurring in Slidell, Louisiana, where Isaac's storm surge filled Bayou Bonfouca and the W-14 Canal, inundating portions of the city with 1 - 5 feet of water. While Isaac is now a weakening minimal-strength tropical storm, it is still a potent rainmaker, and will cause damaging floods all along its path for the next three days. Major river flooding is occurring or is about to occur on a number of rivers in the landfall area. In north central Tangipahoa Parish in southeast Louisiana and southwestern Pike County in southern Mississippi, a mandatory evacuation has been ordered for all low-lying areas and along the Tangipahoa River, due to the potential failure of the Lake Tangipahoa dam. Audubon Park in New Orleans, recorded 11.19" of rain as of 7 pm Wednesday night. An earlier amount of 19" was found to be erroneous, and this is not a 24-hour precipitation record for the city. According to wunderground's weather historian, Christopher C. Burt, New Orleans' greatest 24-hour rainfall on record is 14.01" on July 24 - 25, 1933. The Louisiana official state 24-hour record is 22.00" on Aug. 29, 1962 at Hakberry, although U.S. Army Corps of Engineers `Storm Studies' mentions a 23.80" falling in a 24-hour period at Millers Island during a TS on Aug 7-8, 1940. Storm total was 37.50" over a 60-hour period there during that event.

A few other rainfall totals from Isaac, through 11 am EDT on Thursday:

15.02" Marion, MS
10.09" Hattiesburg, MS
10.15" Gulfport, MS
9.80" Slidell, LA
9.74" Biloxi, MS
8.52" Mobile, AL
5.57" Baton Rouge, LA


Figure 1. Isaac's winds and storm surge overcomes the seawall and floods South Beach Boulevard in Waveland, Miss., Wednesday, Aug. 29, 2012, the seventh anniversary of Hurricane Katrina hitting the Gulf Coast. (AP Photo/Rogelio V. Solis). Waveland experienced a storm surge in excess of 5' for 36 hours.

Isaac's storm surge winds down
Storm surge levels along the coast of Mississippi and surrounding areas are gradually receding, and the surge has finally fallen below 5' at Waveland, which experienced a storm surge in excess of 5' for 36 hours. Isaac's storm surge levels were characteristic of a Category 2 hurricane, and lasted for an exceptionally long period of time. Waveland, Mississippi experienced a peak surge of 8' and peak storm tide of 9' (surge plus the natural high tide), which beat the levels that occurred during Category 2 Hurricane Gustav of 2008 (7' of storm tide.) The peak 11.06' storm surge at Shell Beach, which is in Lake Borgne, 30 miles southeast of New Orleans, exceeded the 9.5' surge recorded there during Gustav. According to an article in nola.com, Isaac pushed a storm surge of 13.6' into Lake Borgne, on the east side of New Orleans. This is not far from the 15.5' storm surge Hurricane Katrina brought to the location. It is quite possible that Isaac's storm surge might have breached levees of the east side of New Orleans, flooding areas inhabited by tens of thousands of people, had the Army Corps of Engineers not completed their $14.5 billion upgrade to the New Orleans flood defenses this year. I estimate that storm surge damage from Isaac will exceed $2 billion. Isaac has likely caused $2.5 billion in insured damage not related to flooding, insurance firm Eqecat estimated yesterday. Here were some of the peak storm surge values that were recorded at NOAA tide gauges during Isaac:

11.1' Shell Beach, LA
8.0' Waveland, MS
3.5' Pensacola, FL
4.6' Pascagoula, MS
3.8' Mobile, AL


Figure 2. A TRMM satellite 3-D view of rainfall on Aug. 28 showed a few very powerful thunderstorms near Isaac's eye were reaching heights of almost 17 km (10.6 miles.) Intense bands of rain around Isaac were occasionally dropping rain at a rate of over 2.75 inches per hour. Image credit: SSAI/NASA, Hal Pierce.

Isaac's storm surge on the Mississippi River
A storm surge estimated at 12' moved up the Mississippi in Plaquemines Parish near Port Sulphur, LA, near 8:30 pm EDT Tuesday, causing overtopping of the levees and flooding of homes in the mandatory evacuation areas behind the levees. These levees were not part of the $14.5 billion levee upgrade New Orleans got after Hurricane Katrina, and were not rated to Category 3 hurricane strength, like the levees protecting New Orleans are. Since salt water is more dense than fresh water, the surge travelled along the bottom of the river, with the fresh water flow of the river lying on top. The surge continued upriver, and before reaching New Orleans, encountered an underwater barrier in Plaquemines Parish. This barrier was constructed by the Army Corps of Engineers beginning on August 15, in order to keep salt water from moving upstream and contaminating drinking water for Plaquemines Parish and New Orleans. Salt water had made it 90 miles upriver to the outskirts of New Orleans, due to the low flow rate of the river (which had dropped 7' below average in height due to the drought of 2012.) According to a spokesperson for the National Weather Service River Forecast Office, this barrier was probably able to completely block the flow of salt water upriver due to Isaac's storm surge, and no salt water made it as far as New Orleans. However, the massive intrusion of ocean water into the river channel caused the mighty Mississippi's fresh water flow to back up for hundreds of miles. Water levels were elevated by 10' in New Orleans (103 miles upstream from the mouth of the Mississippi), 8' in Baton Rouge (228 miles upstream), and 1.4' at Knox Landing, an amazing 314 miles upstream.

Hurricane Kirk in the Central Atlantic
Hurricane Kirk intensified into a 75 mph Category 1 hurricane this morning, becoming the busy 2012 Atlantic hurricane season's fifth hurricane. With the season's mid-point of September 10 still almost 2 weeks away, we've already had 12 named storms and 5 hurricanes, which is close to what an entire season experiences in an average year (11 named storms and 6 hurricanes.) Kirk should stay well out to sea and not trouble any land areas.


Figure 3. Morning satellite image of Hurricane Kirk.

Tropical Storm Leslie forms in the Central Atlantic
Tropical Storm Leslie has formed in the Central Atlantic. Leslie's formation on August 30 puts 2012 in 2nd place for earliest formation date of the season's 12th storm. Only 1995 had an earlier formation date of the season's 12th storm. With records dating back to 1851, this year is only the second time 8 total storms have formed in August. The other year was 2004, when the first storm of the season formed on August 1 (Alex), and the 8th storm (Hermine)
formed on August 29th. Leslie is organizing quickly, and appears destined to become a hurricane before the week is out. Fortunately, Hurricane Kirk is weakening the ridge of high pressure to the north of Leslie, and Leslie is expected to turn to the northwest and miss the Lesser Antilles Islands. In the long term, it remains unclear if Leslie will follow Kirk and fully recurve out to sea. The latest 2 runs of the GFS model have predicted that Leslie will recurve out to sea and not threaten any land areas, but the latest 2 runs of the ECMWF model have predicted that the trough of low pressure pulling Kirk to the northeast will not be strong enough to recurve Leslie out to sea. Instead, the ECMWF predicts that a ridge of high pressure will build in early next week, forcing Leslie more to the northwest, making the storm a potential threat to Bermuda, then to the Northeast U.S. and Canada in 8 - 11 days.

Jeff Masters

Hurricane Isaac Louisiana (apphotos)
Two men walk in the storm surge from Isaac, on Lakeshore Drive along Lake Pontchartrain, as the storm approaches landfall, in New Orleans, Tuesday, Aug. 28, 2012. (AP Photo/Gerald Herbert)
Hurricane Isaac Louisiana
west palm beach flood isaac (alishu)
West Palm Beach flood from Isaac
west palm beach flood isaac
Hurricane Isaac Impacts Navarre Beach & Pier10 (jennjeff1)
Hurricane Isaac versus Navarre Beach Pier, the longest concrete pier on the Gulf of Mexico
Hurricane Isaac Impacts Navarre Beach & Pier10

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I did an update on the Atlantic tropics very early this morning...the usual details are in there...including my custom charts that show the birdseye view of the basin. I do these every 24 to 36 hrs...so feel free to drop in once a day....guarentee 99% of the time it will be updated....

Looks like my aggressive intensity forecast for Kirk was not intense enough....and since I wrote that blog update 98L is now Leslie....
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Quoting Progster:


Doubtful.Its going to stall over pretty dry terrain. Not much energy there to maintain even its mid level rotation over the next few days.


i think he is talking about if it gets back in the Atlantic
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Quoting hurricanewatcher61:
Is it just my untrained eyes or does Leslie look to be missing her next forecast points?


I fully agree that Leslie is keeping West. I really think the models are out to lunch here and that the islands should commence preparation, given how strong she is already.

Just my opinion.
Member Since: August 13, 2007 Posts: 0 Comments: 478
Quoting STXHurricanes2012:
Don't think we've seen the last of Isaac.Notice the track it takes it...takes towards the Atlantic coast!! So don't rule him out pulling an Ivan like the EURO is mentioning!


Doubtful.Its going to stall over pretty dry terrain. Not much energy there to maintain even its mid level rotation over the next few days.
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Quoting interstatelover7165:
Really, cause I'm not believing it... PICS OR IT DIDN'T HAPPEN
...didn't happen. :'(
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Is it just my untrained eyes or does Leslie look to be missing her next forecast points?
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Kirk is probably close to Category 2 status right now. Deep convection going off in the eyewall.

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000
WTNT41 KNHC 302056
TCDAT1

HURRICANE KIRK DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112012
500 PM AST THU AUG 30 2012

KIRK HAS BEEN RAPIDLY INTENSIFYING OVER THE PAST 12-18 HOURS. THE
HURRICANE HAS MAINTAINED A 10-NMI DIAMETER EYE IN VISIBLE SATELLITE
IMAGERY...AND THE 18Z SATELLITE INTENSITY ESTIMATES WERE A CONSENSUS
T4.5/77 KT KT FROM TAFB AND SAB. GIVEN THAT THE CDO FEATURE HAS
EXPANDED AND TOPS HAVE CONTINUED TO COOL...THE INITIAL INTENSITY
HAS BEEN INCREASED TO 80 KT.

THE INITIAL MOTION ESTIMATE IS 330/11 KT. THERE REMAINS NO
SIGNIFICANT CHANGE TO THE PREVIOUS TRACK FORECAST OR REASONING.
KIRK CONTINUES ON TRACK AND THE 18Z MODEL GUIDANCE REMAINS TIGHTLY
CLUSTERED ABOUT THE PREVIOUS FORECAST TRACK. AS A RESULT...THE NEW
FORECAST IS JUST AN EXTENSION OF THE PREVIOUS ADVISORY TRACK...
WHICH LIES VERY CLOSE TO THE TV15 AND TVCA CONSENSUS MODELS.

KIRK APPEARS TO HAVE BEEN ABLE TO OVERCOME ANY DRY AIR ISSUES...SO
SOME ADDITIONAL STRENGTHENING IS FORECAST FOR THE NEXT 24 HOURS.
ALTHOUGH KIRK IS EXPECTED TO REMAIN A RELATIVELY COMPACT
CYCLONE...WHICH MAKES IT VULNERABLE TO SLIGHT INCREASES IN VERTICAL
SHEAR AND ENTRAINMENT OF NEARBY DRY AIR...THE CYCLONE COULD STILL
BECOME A MAJOR HURRICANE BEFORE WEAKENING BEGINS IN 36-48 HOURS. BY
96 HOURS...THE COMBINATION OF STRONG WESTERLY WIND SHEAR AND SSTS
LESS THAN 20C SHOULD RESULT IN KIRK BECOMING AN EXTRATROPICAL
CYCLONE. MERGER WITH A FRONTAL SYSTEM IS EXPECTED BY 120 HOURS. THE
INTENSITY FORECAST IS SIMILAR TO BUT SLIGHTLY HIGHER THAN THE SHIPS
AND LGEM MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 28.2N 50.3W 80 KT 90 MPH
12H 31/0600Z 29.5N 50.8W 90 KT 105 MPH
24H 31/1800Z 31.8N 50.5W 95 KT 110 MPH
36H 01/0600Z 34.4N 49.0W 95 KT 110 MPH
48H 01/1800Z 37.5N 46.1W 85 KT 100 MPH
72H 02/1800Z 44.5N 37.5W 65 KT 75 MPH
96H 03/1800Z 51.5N 25.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 04/1800Z...ABSORBED BY FRONTAL SYSTEM

$$
FORECASTER STEWART
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Quoting wxchaser97:
I truly think Kirk could become a major.


Kirk will never be a major..... He's a Captain dog gone it!
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Quoting angiest:


Up to a point. Euro said Louisiana fairly early on, then switched to FL/AL while GFS locked on to LA.


and then the GFS went back to florida while the Euro went to Texas and then the GFS went back to LA while the Euro went back to Florida and then the GFS went back to Texas while the Euro went to LA and then the GFS went back to florida and then the Euro also went back to Florida and then they both decided to go back to texas and then the Euro went back to florida and then the GFS said it was tired and just settled on LA and the Euro played tagged by itself for a while and then settled on LA..


"reliable models"
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Quoting weatherman12345:
yes but it started the trend to the gulf while the gfs was pretty hellbent on a florida east coast landfall. Another words it was better long range


It was completely wrong on how it got there though, it had it staying south of Cuba and turning north between the Yucutan and Cuba.
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Quoting MiamiHurricanes09:
I told you guys that I'm actually Stacy Stewart. ;)
Really, cause I'm not believing it... PICS OR IT DIDN'T HAPPEN
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..i still think Kirk is about to get squashed by dry air, first effects showing in a few hours.
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Not saying Leslie won't recurve, but I've seen that recurve tune played before and the storms didn't dance to it.
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For all in the islands, prepare for Leslie, i.e. dont panic, but prepare.

I have a feeling this will be one for the books.
Member Since: August 13, 2007 Posts: 0 Comments: 478
Quoting stormwatcherCI:
...KIRK RAPIDLY STRENGTHENING OVER THE OPEN ATLANTIC...
------------------------------------------------- -------------------------------

5:00 PM AST Thu Aug 30
Location: 28.2°N 50.3°W
Moving: NNW at 13 mph
Min pressure: 982 mb
Max sustained: 90 mph

I told you guys that I'm actually Stacy Stewart. ;)
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Quoting AnthonyJKenn:
Meanwhile....the tropical segment of the story of Issac can finally be closed. The latest 5 PM EDT (and final) advisory is now out:

BULLETIN
TROPICAL DEPRESSION ISAAC ADVISORY NUMBER 39
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT THU AUG 30 2012

...SLOW-MOVING ISAAC WEAKENS TO A DEPRESSION OVER NORTHERN
LOUISIANA...
...FLOODING RAINS CONTINUE ACROSS SOUTHEASTERN LOUISIANA AND
MISSISSIPPI...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...32.7N 92.6W
ABOUT 35 MI...55 KM WNW OF MONROE LOUISIANA
ABOUT 40 MI...60 KM SSE OF EL DORADO ARKANSAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES


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

ALL COASTAL WARNINGS HAVE BEEN DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 400 PM CDT...2100 UTC...THE CENTER OF TROPICAL DEPRESSION ISAAC
WAS LOCATED NEAR LATITUDE 32.7 NORTH...LONGITUDE 92.6 WEST. THE
DEPRESSION IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 12 MPH...19
KM/H. A TURN TOWARD THE NORTH IS EXPECTED BY LATE TONIGHT OR EARLY
FRIDAY. ON THE FORECAST TRACK...THE CENTER OF ISAAC WILL CONTINUE
TO MOVE OVER LOUISIANA TODAY...OVER ARKANSAS ON FRIDAY...AND OVER
SOUTHERN MISSOURI FRIDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. GRADUAL WEAKENING IS FORECAST DURING THE NEXT 48 HOURS...AND
ISAAC IS EXPECTED TO BECOME A POST-TROPICAL REMNANT LOW PRESSURE
SYSTEM BY SATURDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON NEARBY SURFACE
OBSERVATIONS IS 995 MB...29.38 INCHES.


HAZARDS AFFECTING LAND
----------------------
EVEN THOUGH ISAAC IS NO LONGER A TROPICAL STORM...DANGEROUS
HAZARDS FROM STORM SURGE...INLAND FLOODING...AND TORNADOES ARE
STILL OCCURRING.

STORM SURGE...WATER LEVELS WILL REMAIN ELEVATED IN SOUTHEASTERN
LOUISIANA AND COASTAL MISSISSIPPI THROUGH TONIGHT...AND GRADUALLY
SUBSIDE TOMORROW. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE
SEE PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE.

BASED ON OBSERVATIONS FROM NATIONAL OCEAN SERVICE TIDE GAGES...AT
NEW CANAL STATION LOUISIANA...A STORM SURGE OF MORE THAN 5 FEET IS
PERSISTING ALONG THE SOUTHERN SHORE OF LAKE PONTCHARTRAIN...AND A
STORM SURGE VALUE OF NEAR 4 FEET CONTINUES AT WAVELAND MISSISSIPPI.

WIND...TROPICAL-STORM-FORCE WIND GUSTS COULD OCCUR ALONG THE COASTS
OF SOUTHEASTERN LOUISIANA AND MISSISSIPPI THROUGH THIS AFTERNOON.

RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 7 TO 14 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 25 INCHES
POSSIBLE...OVER NORTHERN AND EASTERN LOUISIANA....MUCH OF
MISSISSIPPI...SOUTHWESTERN ALABAMA...ARKANSAS...AND INTO SOUTHERN
MISSOURI THROUGH FRIDAY. THESE RAINS COULD RESULT IN SIGNIFICANT
LOWLAND FLOODING. THE HEAVY RAIN POTENTIAL WILL BE SPREADING
EASTWARD THIS WEEKEND INTO PORTIONS OF THE MID-WEST AND OHIO VALLEY
REGIONS.

TORNADOES...TORNADOES ARE POSSIBLE ALONG THE CENTRAL GULF COAST
REGION AND PARTS OF THE LOWER MISSISSIPPI RIVER VALLEY THROUGH
TONIGHT.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE WEST COAST OF FLORIDA AND THE NORTHERN GULF COAST THROUGH
TONIGHT BEFORE SUBSIDING ON SATURDAY.


NEXT ADVISORY
-------------
THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON THIS SYSTEM. FUTURE INFORMATION ON THIS SYSTEM CAN BE
FOUND IN PUBLIC ADVISORIES ISSUED BY THE HYDROMETEOROLOGICAL
PREDICTION CENTER...UNDER AWIPS HEADER TCPAT4 AND WMO HEADER WTNT34
KWNH...BEGINNING AT 10 PM CDT.


$$
FORECASTER STEWART

Goodbye, and good riddance.
Very truly now, RIP ISAAC
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H
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Quoting tropicfreak:


I agree.... if I were there I'd worry a little bit. That is too close for comfort.

I know that we must always follow the bulletins especially if the models are not in agreement. But for this storm it looks like they all agree that Leslie is going to pass well to the northeast of PR.So I won't worry too much (yet).
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OVERLAND DEPRESSION 09L
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Hope everybody made it safely through isaac. Unfortunately that will probly not be the case. Prayers 4 u today. Remember to exercise caution in the aftermath, especially the dangerous critters
Member Since: April 26, 2006 Posts: 5 Comments: 3075
Where are my peeps?.I'm in the zombie pit right now!.
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Satellite imagery of 2045utc is indicating a hot tower is developing with Kirk. Also a convective explosion for Leslie is occurring. This is going to be an intense tropical cyclone in 2 days.
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Quoting Redbull77:

What does it show


look at the final track at the NHC
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Quoting angiest:


Up to a point. Euro said Louisiana fairly early on, then switched to FL/AL while GFS locked on to LA.


I say GFS did best in the short term, but the long term forecast belong to the Euro. I call them the dynamic duo those two together are an axcellent tool.
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Quoting Tazmanian:
a TS watch or hurricane watch will likey be needed for parts of the N Lesser Antilles Islands and PR has the storms is by passing them too the WNW


I agree.... if I were there I'd worry a little bit. That is too close for comfort.
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Quoting washingtonian115:
Thank goodness Isaac is dead.


He's not quite dead here yet. In fact, we are in a dry spell and getting the strongest winds that we have seen from him. And here in central Ms, its going to be another long night with these bands coming out of south Ms. Winds are at around 50mph here right now.
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Quoting STXHurricanes2012:
Don't think we've seen the last of Isaac.Notice the track it takes it...takes towards the Atlantic coast!! So don't rule him out pulling an Ivan like the EURO is mentioning!

What does it show
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This was interesting so I thought I'd bring this back up..

Here was the prediction for the 2005 Atlantic hurricane season back in April 2005..13/7/3..May 2012 13/5/2..

Very interesting...
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TROPICAL DEPRESSION ISAAC DISCUSSION NUMBER 39
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT THU AUG 30 2012

SURFACE OBSERVATIONS AND NOAA DOPPLER WEATHER RADARS INDICATE THAT
ISAAC IS MOVING NORTH-NORTHWESTWARD AT 340/11 KT. ISAAC WILL
GRADUALLY TURN TO THE NORTH OVER THE NEXT 24-36 HOURS...AND MOVE
ACROSS ARKANSAS AND INTO MISSOURI. BY DAY 3...THE REMNANTS OF ISAAC
SHOULD TURN NORTHEASTWARD AND THEN EASTWARD AS THE SYSTEM MOVES
INTO WEAK MID-LATITUDE WESTERLY FLOW. THE OFFICIAL TRACK FORECAST
IS VERY CLOSE TO THE PREVIOUS ONE...AND LIES JUST TO THE RIGHT OF
THE CONSENSUS MODELS TCVA AND TV15.

THE INITIAL INTENSITY HAS BEEN DECREASED TO 30 KT...BASED ON SURFACE
OBSERVATIONS AND DOPPLER RADAR VELOCITY DATA. ISAAC WILL CONTINUE
TO WEAKEN OVER LAND AND IT IS EXPECTED TO BECOME A POST-TROPICAL
REMNANT LOW BY SATURDAY...IF NOT SOONER. THE OFFICIAL INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS ONE...AND CLOSELY FOLLOWS THE
DECAY-SHIPS STATISTICAL-DYNAMICAL INTENSITY MODEL.

HEAVY RAINFALL AND A SIGNIFICANT FLOOD THREAT WILL CONTINUE TO
SPREAD INLAND ACROSS PORTIONS OF THE CENTRAL UNITED STATES DURING
THE NEXT SEVERAL DAYS. WATER LEVELS ALONG THE NORTHERN GULF COAST
WILL REMAIN ELEVATED THROUGH THIS EVENING...AND THEN GRADUALLY
SUBSIDE ON FRIDAY. THE THREAT FOR TORNADOES WITH THIS SYSTEM WILL
CONTINUE THROUGH TONIGHT.

THIS IS THE LAST ADVISORY ON ISAAC ISSUED BY THE NATIONAL HURRICANE
CENTER. FUTURE INFORMATION ON THIS SYSTEM CAN BE FOUND IN PUBLIC
ADVISORIES ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER...
UNDER AWIPS HEADER TCPAT4 AND WMO HEADER WTNT34 KWNH...BEGINNING AT
10 PM CDT.

FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 32.7N 92.6W 30 KT 35 MPH...INLAND
12H 31/0600Z 34.0N 93.0W 25 KT 30 MPH...INLAND
24H 31/1800Z 36.0N 93.2W 20 KT 25 MPH...INLAND
36H 01/0600Z 37.7N 92.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 01/1800Z 38.6N 91.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 02/1800Z 39.5N 88.5W 15 KT 15 MPH...POST-TROP/REMNT LOW
96H 03/1800Z 39.5N 85.5W 15 KT 15 MPH...POST-TROP/REMNT LOW
120H 04/1800Z 38.5N 82.5W 15 KT 15 MPH...POST-TROP/REMNT LOW
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Its raining so hard and the wind is so strong that it looks like winds of a strong ts lights have been on an off.People even thought that a tornado was coming its very dark outside.I predict Kirk will be our first major and Leslie the second.bye have a nice day everyone.
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Don't think we've seen the last of Isaac.Notice the track it takes it...takes towards the Atlantic coast!! So don't rule him out pulling an Ivan like the EURO is mentioning!
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Quoting will40:


well i tried to push him just a lil farther west but i guess the shields stopped that


:) I think that shield worked a little too well. I can't remember the last time anything tropical rained on TX.
Ike? Maybe?
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a TS watch or hurricane watch will likey be needed for parts of the N Lesser Antilles Islands and PR has the storms is by passing them too the WNW
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Quoting wxchaser97:
I truly think Kirk could become a major.


He aint looking like a red shirt


Not seen anything else about that dam for a while aside from mandatory evac. I always thought one of the scariest places to live was downstream from a dam, nightmare. I think the original Superman movie did it to me when I was a kid!
Member Since: October 12, 2011 Posts: 0 Comments: 841
Quoting AnthonyJKenn:
Meanwhile....the tropical segment of the story of Issac can finally be closed. The latest 5 PM EDT (and final) advisory is now out:

BULLETIN
TROPICAL DEPRESSION ISAAC ADVISORY NUMBER 39
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT THU AUG 30 2012

...SLOW-MOVING ISAAC WEAKENS TO A DEPRESSION OVER NORTHERN
LOUISIANA...
...FLOODING RAINS CONTINUE ACROSS SOUTHEASTERN LOUISIANA AND
MISSISSIPPI...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...32.7N 92.6W
ABOUT 35 MI...55 KM WNW OF MONROE LOUISIANA
ABOUT 40 MI...60 KM SSE OF EL DORADO ARKANSAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES


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

ALL COASTAL WARNINGS HAVE BEEN DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 400 PM CDT...2100 UTC...THE CENTER OF TROPICAL DEPRESSION ISAAC
WAS LOCATED NEAR LATITUDE 32.7 NORTH...LONGITUDE 92.6 WEST. THE
DEPRESSION IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 12 MPH...19
KM/H. A TURN TOWARD THE NORTH IS EXPECTED BY LATE TONIGHT OR EARLY
FRIDAY. ON THE FORECAST TRACK...THE CENTER OF ISAAC WILL CONTINUE
TO MOVE OVER LOUISIANA TODAY...OVER ARKANSAS ON FRIDAY...AND OVER
SOUTHERN MISSOURI FRIDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. GRADUAL WEAKENING IS FORECAST DURING THE NEXT 48 HOURS...AND
ISAAC IS EXPECTED TO BECOME A POST-TROPICAL REMNANT LOW PRESSURE
SYSTEM BY SATURDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON NEARBY SURFACE
OBSERVATIONS IS 995 MB...29.38 INCHES.


HAZARDS AFFECTING LAND
----------------------
EVEN THOUGH ISAAC IS NO LONGER A TROPICAL STORM...DANGEROUS
HAZARDS FROM STORM SURGE...INLAND FLOODING...AND TORNADOES ARE
STILL OCCURRING.

STORM SURGE...WATER LEVELS WILL REMAIN ELEVATED IN SOUTHEASTERN
LOUISIANA AND COASTAL MISSISSIPPI THROUGH TONIGHT...AND GRADUALLY
SUBSIDE TOMORROW. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE
SEE PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE.

BASED ON OBSERVATIONS FROM NATIONAL OCEAN SERVICE TIDE GAGES...AT
NEW CANAL STATION LOUISIANA...A STORM SURGE OF MORE THAN 5 FEET IS
PERSISTING ALONG THE SOUTHERN SHORE OF LAKE PONTCHARTRAIN...AND A
STORM SURGE VALUE OF NEAR 4 FEET CONTINUES AT WAVELAND MISSISSIPPI.

WIND...TROPICAL-STORM-FORCE WIND GUSTS COULD OCCUR ALONG THE COASTS
OF SOUTHEASTERN LOUISIANA AND MISSISSIPPI THROUGH THIS AFTERNOON.

RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 7 TO 14 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 25 INCHES
POSSIBLE...OVER NORTHERN AND EASTERN LOUISIANA....MUCH OF
MISSISSIPPI...SOUTHWESTERN ALABAMA...ARKANSAS...AND INTO SOUTHERN
MISSOURI THROUGH FRIDAY. THESE RAINS COULD RESULT IN SIGNIFICANT
LOWLAND FLOODING. THE HEAVY RAIN POTENTIAL WILL BE SPREADING
EASTWARD THIS WEEKEND INTO PORTIONS OF THE MID-WEST AND OHIO VALLEY
REGIONS.

TORNADOES...TORNADOES ARE POSSIBLE ALONG THE CENTRAL GULF COAST
REGION AND PARTS OF THE LOWER MISSISSIPPI RIVER VALLEY THROUGH
TONIGHT.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE WEST COAST OF FLORIDA AND THE NORTHERN GULF COAST THROUGH
TONIGHT BEFORE SUBSIDING ON SATURDAY.


NEXT ADVISORY
-------------
THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON THIS SYSTEM. FUTURE INFORMATION ON THIS SYSTEM CAN BE
FOUND IN PUBLIC ADVISORIES ISSUED BY THE HYDROMETEOROLOGICAL
PREDICTION CENTER...UNDER AWIPS HEADER TCPAT4 AND WMO HEADER WTNT34
KWNH...BEGINNING AT 10 PM CDT.


$$
FORECASTER STEWART

Goodbye, and good riddance.

For the NHC yes but the HPC is still going to issue advisories on it cause its still producing flooding rains!
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Thank goodness Isaac is dead.
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Quoting AtHomeInTX:


Yeah. It's been dry for a while in ETX. Little rain always helps. Hopefully he'll rain on the drought areas and actually do something good.


well i tried to push him just a lil farther west but i guess the shields stopped that
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Meanwhile....the tropical segment of the story of Issac can finally be closed. The latest 5 PM EDT (and final) advisory is now out:

BULLETIN
TROPICAL DEPRESSION ISAAC ADVISORY NUMBER 39
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
400 PM CDT THU AUG 30 2012

...SLOW-MOVING ISAAC WEAKENS TO A DEPRESSION OVER NORTHERN
LOUISIANA...
...FLOODING RAINS CONTINUE ACROSS SOUTHEASTERN LOUISIANA AND
MISSISSIPPI...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...32.7N 92.6W
ABOUT 35 MI...55 KM WNW OF MONROE LOUISIANA
ABOUT 40 MI...60 KM SSE OF EL DORADO ARKANSAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES


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

ALL COASTAL WARNINGS HAVE BEEN DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 400 PM CDT...2100 UTC...THE CENTER OF TROPICAL DEPRESSION ISAAC
WAS LOCATED NEAR LATITUDE 32.7 NORTH...LONGITUDE 92.6 WEST. THE
DEPRESSION IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 12 MPH...19
KM/H. A TURN TOWARD THE NORTH IS EXPECTED BY LATE TONIGHT OR EARLY
FRIDAY. ON THE FORECAST TRACK...THE CENTER OF ISAAC WILL CONTINUE
TO MOVE OVER LOUISIANA TODAY...OVER ARKANSAS ON FRIDAY...AND OVER
SOUTHERN MISSOURI FRIDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. GRADUAL WEAKENING IS FORECAST DURING THE NEXT 48 HOURS...AND
ISAAC IS EXPECTED TO BECOME A POST-TROPICAL REMNANT LOW PRESSURE
SYSTEM BY SATURDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON NEARBY SURFACE
OBSERVATIONS IS 995 MB...29.38 INCHES.


HAZARDS AFFECTING LAND
----------------------
EVEN THOUGH ISAAC IS NO LONGER A TROPICAL STORM...DANGEROUS
HAZARDS FROM STORM SURGE...INLAND FLOODING...AND TORNADOES ARE
STILL OCCURRING.

STORM SURGE...WATER LEVELS WILL REMAIN ELEVATED IN SOUTHEASTERN
LOUISIANA AND COASTAL MISSISSIPPI THROUGH TONIGHT...AND GRADUALLY
SUBSIDE TOMORROW. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE
SEE PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE.

BASED ON OBSERVATIONS FROM NATIONAL OCEAN SERVICE TIDE GAGES...AT
NEW CANAL STATION LOUISIANA...A STORM SURGE OF MORE THAN 5 FEET IS
PERSISTING ALONG THE SOUTHERN SHORE OF LAKE PONTCHARTRAIN...AND A
STORM SURGE VALUE OF NEAR 4 FEET CONTINUES AT WAVELAND MISSISSIPPI.

WIND...TROPICAL-STORM-FORCE WIND GUSTS COULD OCCUR ALONG THE COASTS
OF SOUTHEASTERN LOUISIANA AND MISSISSIPPI THROUGH THIS AFTERNOON.

RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 7 TO 14 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 25 INCHES
POSSIBLE...OVER NORTHERN AND EASTERN LOUISIANA....MUCH OF
MISSISSIPPI...SOUTHWESTERN ALABAMA...ARKANSAS...AND INTO SOUTHERN
MISSOURI THROUGH FRIDAY. THESE RAINS COULD RESULT IN SIGNIFICANT
LOWLAND FLOODING. THE HEAVY RAIN POTENTIAL WILL BE SPREADING
EASTWARD THIS WEEKEND INTO PORTIONS OF THE MID-WEST AND OHIO VALLEY
REGIONS.

TORNADOES...TORNADOES ARE POSSIBLE ALONG THE CENTRAL GULF COAST
REGION AND PARTS OF THE LOWER MISSISSIPPI RIVER VALLEY THROUGH
TONIGHT.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE WEST COAST OF FLORIDA AND THE NORTHERN GULF COAST THROUGH
TONIGHT BEFORE SUBSIDING ON SATURDAY.


NEXT ADVISORY
-------------
THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON THIS SYSTEM. FUTURE INFORMATION ON THIS SYSTEM CAN BE
FOUND IN PUBLIC ADVISORIES ISSUED BY THE HYDROMETEOROLOGICAL
PREDICTION CENTER...UNDER AWIPS HEADER TCPAT4 AND WMO HEADER WTNT34
KWNH...BEGINNING AT 10 PM CDT.


$$
FORECASTER STEWART

Goodbye, and good riddance.
Member Since: Posts: Comments:
Quoting will40:


did some of the areas need rain?


Yeah. It's been dry for a while in ETX. Little rain always helps. Hopefully he'll rain on the drought areas and actually do something good.
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too bad we cant get a recon in there for Captain Kirk
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Quoting scott39:
We are sick of Isaac on the Gulf Coast!
I feel your pain....Been there
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Glad kirk is out to sea.More beautiful to look at them out there vs. Isaac ugliness when he was making a run for land...
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It's distressing to see fire danger alerts in upper-Midwest corn states; Iowa, Nebraska, Minnesota.

Maybe some of that Isaac moisture can be wished north and west.
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Quoting will40:


did some of the areas need rain?


Not really. Generally east of I45 has been fine with rain. It's mostly the central and western parts of the state that need it.
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I truly think Kirk could become a major.
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Quoting weatherman12345:
ECMWF did do better with Isaac. You have to take that into consideration


Up to a point. Euro said Louisiana fairly early on, then switched to FL/AL while GFS locked on to LA.
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2012
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Quoting AtHomeInTX:


Lol. I guess not. Was wondering earlier why we had a west wind instead of a north. I thought we were on the wrong side of the storm. :)


did some of the areas need rain?
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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.