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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Quoting 12george1:
Where is the HPC advisory on Isaac?

Never mind
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Where is the HPC advisory on Isaac?
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Quoting AussieStorm:

of course they do, Maybe people should relay on what they see with there own eyes and not what they are being told.


God forbid many of these ppl would think for themselves, they wouldn't have anyone to use as a scapegoat! Quite frankly I am sick of ppl that can't think for themselves and rely on someone else to tell them what to do or IGNORE warnings and then cry for "help" and risk emergency personnel's lives to save them!
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Quoting psuweathernewbie1:
Tropical Storm Leslie could very well make a loop near Bermuda if the trough moves off to the northeast and the Bermuda/Azores high builds back westward with time.

OK, you were calling for longterm W movement early this AM, which I'm down with, but a loop-de-loop? Crazy talk, man.
Member Since: August 4, 2007 Posts: 0 Comments: 3280
One good side effect of hurricanes:


24 hour weather on THE WEATHER CHANNEL
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1032. WWPR
THE INITIAL MOTION IS 280/16. LESLIE IS CURRENTLY ON THE SOUTH SIDE
OF THE SUBTROPICAL RIDGE...WHICH SHOULD STEER THE SYSTEM GENERALLY
WEST-NORTHWESTWARD FOR THE NEXT 48 HR OR SO. AFTER THAT...THE
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT A MID-/UPPER-LEVEL
SHORTWAVE TROUGH...CURRENTLY SEEN IN WATER VAPOR IMAGERY MOVING OFF
OF THE COAST OF THE NORTHEASTERN UNITED STATES...SHOULD DEVELOP
INTO A CUT-OFF LOW BETWEEN BERMUDA AND THE BAHAMAS. THIS LOW IS
FORECAST TO BREAK THE SUBTROPICAL RIDGE AT THE MID-/UPPER-LEVELS...
AND EXTEND FAR ENOUGH VERTICALLY DOWNWARD TO WEAKEN THE RIDGE AT
700-850 MB. THIS EVOLUTION SHOULD CAUSE LESLIE TO GRADUALLY TURN
NORTHWARD ON THE EASTERN SIDE OF THE CUT-OFF LOW AFTER THE 48 HR
POINT. THE TRACK GUIDANCE IS IN GOOD AGREEMENT WITH THIS
SCENARIO...AND THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS
TRACK THROUGH 96 HR. IT SHOULD BE NOTED THAT THE TRACK GUIDANCE
STARTS TO DIVERGE AT 120 HR REGARDING HOW QUICKLY LESLIE SHOULD
ENCOUNTER THE WESTERLIES...AND BASED ON THIS SPREAD...THE TRACK
FORECAST CALLS FOR A SLOWER AND MORE NORTHERLY MOTION NEAR THAT
TIME.

So when do these 48 hours begin?
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Quoting tropicfreak:
Even though it is still moving west and even a slight dip WSW they will not give up on a WNW then NW movement.



i'm not saying a word!
Member Since: April 29, 2007 Posts: 0 Comments: 8134
Quoting AussieStorm:

of course they do, Maybe people should relay on what they see with there own eyes and not what they are being told.


The NHC is expecting Leslie to make a WNW turn right away or within the next 12 hours, and I just don't see that happening. It is strengthening steadily but it's moving too fast, and it just might miss the weakness.
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Quoting trHUrrIXC5MMX:


also this storm could be a major


Still a possibility.
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Quoting tropicfreak:


Regardless, people in the Lesser Antillies need to be on their toes...

of course they do, Maybe people should relay on what they see with there own eyes and not what they are being told.
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Tropical Storm Leslie could very well make a loop near Bermuda if the trough moves off to the northeast and the Bermuda/Azores high builds back westward with time.
Member Since: August 4, 2012 Posts: 0 Comments: 42
Quoting Civicane49:
BULLETIN
TROPICAL STORM LESLIE ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012
1100 PM EDT THU AUG 30 2012

...LESLIE CONTINUING TO STRENGTHEN OVER THE OPEN TROPICAL
ATLANTIC...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.7N 46.8W
ABOUT 1010 MI...1625 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES


also this storm could be a major
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Quoting AussieStorm:

It's the NHC, what do you expect. Even when Isaac was going SW after landfall they kept saying he was going NNW or WNW. Never did they say, stalled or stationary.


Regardless, people in the Lesser Antillies need to be on their toes...
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Quoting HrDelta:


I'm imagining Major occurring between 24-36 hours out.

Either that or, we have a surprise tomorrow morning. Both are plausible.


yet mee too.. could very well be a major
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HURRICANE KIRK DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112012
1100 PM AST THU AUG 30 2012

KIRK CONTINUES TO MAINTAIN AN IMPRESSIVE CLOUD PATTERN...WITH A
SYMMETRIC CENTRAL DENSE OVERCAST COMPRISED OF COLD CLOUD TOP
TEMPERATURES. ALTHOUGH THE EARLIER RAPID INTENSIFICATION PHASE
SEEMS TO HAVE LEVELED OFF...THE EYE HAS WARMED FURTHER AND BECOME
BETTER DEFINED IN THE LAST FEW HOURS. DVORAK INTENSITY ESTIMATES
ARE A CONSENSUS 4.5 FROM TAFB AND SAB...BUT THE LATEST ADT VALUES
HAVE BEEN RUNNING CLOSER TO T5.0. THE INITIAL INTENSITY ESTIMATE IS
RAISED TO 85 KT IN AGREEMENT WITH A BLEND OF THESE DATA SOURCES.
KIRK HAS ANOTHER DAY OR SO TRAVERSING WARM WATERS IN A RELATIVELY
LOW SHEAR ENVIRONMENT. THE CYCLONE ALSO HAS A WELL-ESTABLISHED
OUTFLOW SINK TO THE EAST AND IS FORECAST TO APPROACH A JET TO THE
NORTHWEST...WHICH COULD SERVE AS AN ADDITIONAL OUTFLOW CHANNEL.
THESE FACTORS...ALONG WITH THE STATISTICAL-DYNAMICAL GUIDANCE...
SUGGESTS A PEAK INTENSITY OCCURRING AROUND OR JUST AFTER THE POINT
OF RECURVATURE. A SHARP INCREASE IN SHEAR AND A TRACK OVER RAPIDLY
DECREASING SEA SURFACE TEMPERATURES BEYOND 48 HOURS SHOULD RESULT
IN STEADY OR EVEN RAPID WEAKENING. A QUICK-MOVING FRONTAL ZONE
SHOULD BEGIN TO OVERTAKE KIRK IN 2-3 DAYS...RESULTING IN
EXTRATROPICAL TRANSITION JUST AROUND 72 HOURS AND ABSORPTION IN 96
HOURS. THE NHC INTENSITY FORECAST IS NEARLY IDENTICAL TO THE
PREVIOUS ONE...AND IS SLIGHTLY HIGHER THAN THE SHIPS/LGEM INTENSITY
AIDS.

THE INITIAL MOTION ESTIMATE HAS VEERED A HAIR TO THE RIGHT AND IS
335/10. THE TRACK FORECAST IS CLEAR-CUT. KIRK HAS REACHED THE
WESTERN END OF SUBTROPICAL RIDGE TO THE EAST AND SHOULD UNDERGO
RECURVATURE IN THE NEXT 24 HOURS. THE CYCLONE SHOULD THEN GRADUALLY
BECOME EMBEDDED IN MID-LATITUDE WESTERLIES...AND ACCELERATE AT WARP
SPEED WITH THE APPROACH OF A POTENT MID-LATITUDE SHORTWAVE OVER THE
CANADIAN MARITIME PROVINCES IN 36-48 HOURS. THE NEW TRACK FORECAST
IS VIRTUALLY UNCHANGED FROM THE PREVIOUS ONE...GIVEN THE EXCELLENT
AGREEMENT IN THE NUMERICAL MODEL GUIDANCE.


FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 29.0N 50.7W 85 KT 100 MPH
12H 31/1200Z 30.5N 50.8W 90 KT 105 MPH
24H 01/0000Z 33.0N 50.0W 95 KT 110 MPH
36H 01/1200Z 35.8N 47.9W 95 KT 110 MPH
48H 02/0000Z 38.7N 44.5W 85 KT 100 MPH
72H 03/0000Z 46.2N 34.3W 65 KT 75 MPH...POST-TROP/EXTRATROP
96H 04/0000Z 52.0N 20.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 05/0000Z...DISSIPATED

$$
FORECASTER KIMBERLAIN
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Quoting pottery:

Goodness me!
They'll be pumping, next. (the ridge, the RIDGE)
Everyone under the age of 60, get off the blog.
Thank god i'll be 65 in a few days
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Quoting tropicfreak:
Even though it is still moving west and even a slight dip WSW they will not give up on a WNW then NW movement.


It's the NHC, what do you expect. Even when Isaac was going SW after landfall they kept saying he was going NNW or WNW. Never did they say, stalled or stationary. Did they forecast the stall when they should of seen the blocking high to his north, no.
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1020. HrDelta
Quoting Civicane49:
000
WTNT21 KNHC 310243
TCMAT1

HURRICANE KIRK FORECAST/ADVISORY NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112012
0300 UTC FRI AUG 31 2012

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

HURRICANE CENTER LOCATED NEAR 29.0N 50.7W AT 31/0300Z
POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 335 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 980 MB
EYE DIAMETER 10 NM
MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 105 KT.
64 KT....... 15NE 10SE 10SW 15NW.
50 KT....... 30NE 20SE 20SW 30NW.
34 KT....... 60NE 40SE 30SW 50NW.
12 FT SEAS..120NE 90SE 0SW 60NW.
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 29.0N 50.7W AT 31/0300Z
AT 31/0000Z CENTER WAS LOCATED NEAR 28.5N 50.5W

FORECAST VALID 31/1200Z 30.5N 50.8W
MAX WIND 90 KT...GUSTS 110 KT.
64 KT... 15NE 15SE 10SW 15NW.
50 KT... 40NE 30SE 20SW 30NW.
34 KT... 80NE 70SE 50SW 70NW.

FORECAST VALID 01/0000Z 33.0N 50.0W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 15NE 15SE 10SW 10NW.
50 KT... 40NE 40SE 30SW 30NW.
34 KT... 90NE 80SE 60SW 70NW.

FORECAST VALID 01/1200Z 35.8N 47.9W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 20NE 20SE 10SW 10NW.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...100NE 100SE 80SW 70NW.

FORECAST VALID 02/0000Z 38.7N 44.5W
MAX WIND 85 KT...GUSTS 105 KT.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...100NE 110SE 90SW 80NW.

FORECAST VALID 03/0000Z 46.2N 34.3W...POST-TROP/EXTRATROP
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...110NE 130SE 100SW 80NW.

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 04/0000Z 52.0N 20.0W...POST-TROP/EXTRATROP
MAX WIND 45 KT...GUSTS 55 KT.

OUTLOOK VALID 05/0000Z...ABSORBED BY FRONTAL ZONE

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 29.0N 50.7W

NEXT ADVISORY AT 31/0900Z

$$
FORECASTER KIMBERLAIN


I'm imagining Major occurring between 24-36 hours out.

Either that or, we have a surprise tomorrow morning. Both are plausible.
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Even though it is still moving west and even a slight dip WSW they will not give up on a WNW then NW movement.

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RESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 335 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 980 MB
EYE DIAMETER 10 NM
MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 105 KT.
64 KT....... 15NE 10SE 10SW 15NW.
50 KT....... 30NE 20SE 20SW 30NW.
34 KT....... 60NE 40SE 30SW 50NW.
12 FT SEAS..120NE 90SE 0SW 60NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
Member Since: March 16, 2012 Posts: 127 Comments: 7972
000
WTNT21 KNHC 310243
TCMAT1

HURRICANE KIRK FORECAST/ADVISORY NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112012
0300 UTC FRI AUG 31 2012

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

HURRICANE CENTER LOCATED NEAR 29.0N 50.7W AT 31/0300Z
POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 335 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 980 MB
EYE DIAMETER 10 NM
MAX SUSTAINED WINDS 85 KT WITH GUSTS TO 105 KT.
64 KT....... 15NE 10SE 10SW 15NW.
50 KT....... 30NE 20SE 20SW 30NW.
34 KT....... 60NE 40SE 30SW 50NW.
12 FT SEAS..120NE 90SE 0SW 60NW.
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 29.0N 50.7W AT 31/0300Z
AT 31/0000Z CENTER WAS LOCATED NEAR 28.5N 50.5W

FORECAST VALID 31/1200Z 30.5N 50.8W
MAX WIND 90 KT...GUSTS 110 KT.
64 KT... 15NE 15SE 10SW 15NW.
50 KT... 40NE 30SE 20SW 30NW.
34 KT... 80NE 70SE 50SW 70NW.

FORECAST VALID 01/0000Z 33.0N 50.0W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 15NE 15SE 10SW 10NW.
50 KT... 40NE 40SE 30SW 30NW.
34 KT... 90NE 80SE 60SW 70NW.

FORECAST VALID 01/1200Z 35.8N 47.9W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 20NE 20SE 10SW 10NW.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...100NE 100SE 80SW 70NW.

FORECAST VALID 02/0000Z 38.7N 44.5W
MAX WIND 85 KT...GUSTS 105 KT.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...100NE 110SE 90SW 80NW.

FORECAST VALID 03/0000Z 46.2N 34.3W...POST-TROP/EXTRATROP
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...110NE 130SE 100SW 80NW.

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 04/0000Z 52.0N 20.0W...POST-TROP/EXTRATROP
MAX WIND 45 KT...GUSTS 55 KT.

OUTLOOK VALID 05/0000Z...ABSORBED BY FRONTAL ZONE

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 29.0N 50.7W

NEXT ADVISORY AT 31/0900Z

$$
FORECASTER KIMBERLAIN
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Hurricane Kirk is now a Category 2 hurricane.
Member Since: July 6, 2010 Posts: 113 Comments: 32810
Going to start making these.

Member Since: July 6, 2010 Posts: 113 Comments: 32810
TROPICAL STORM LESLIE DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012
1100 PM EDT THU AUG 30 2012

CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF
LESLIE IS LOCATED TO THE NORTHEAST OF THE MAIN CONVECTIVE
MASS...MOST LIKELY DUE TO LIGHT/MODERATE NORTHEASTERLY VERTICAL
WIND SHEAR. SATELLITE INTENSITY ESTIMATES ARE 45 KT FROM TAFB AND
SAB. IN ADDITION...NOAA BUOY 41041 REPORTED 1004 MB AND
NORTHWESTERLY WINDS OF 20-25 KT AS THE CENTER PASSED TO THE NORTH.
BASED ON THESE DATA...THE INITIAL INTENSITY IS INCREASED TO 45 KT.

THE INITIAL MOTION IS 280/16. LESLIE IS CURRENTLY ON THE SOUTH SIDE
OF THE SUBTROPICAL RIDGE...WHICH SHOULD STEER THE SYSTEM GENERALLY
WEST-NORTHWESTWARD FOR THE NEXT 48 HR OR SO. AFTER THAT...THE
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT A MID-/UPPER-LEVEL
SHORTWAVE TROUGH...CURRENTLY SEEN IN WATER VAPOR IMAGERY MOVING OFF
OF THE COAST OF THE NORTHEASTERN UNITED STATES...SHOULD DEVELOP
INTO A CUT-OFF LOW BETWEEN BERMUDA AND THE BAHAMAS. THIS LOW IS
FORECAST TO BREAK THE SUBTROPICAL RIDGE AT THE MID-/UPPER-LEVELS...
AND EXTEND FAR ENOUGH VERTICALLY DOWNWARD TO WEAKEN THE RIDGE AT
700-850 MB. THIS EVOLUTION SHOULD CAUSE LESLIE TO GRADUALLY TURN
NORTHWARD ON THE EASTERN SIDE OF THE CUT-OFF LOW AFTER THE 48 HR
POINT. THE TRACK GUIDANCE IS IN GOOD AGREEMENT WITH THIS
SCENARIO...AND THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS
TRACK THROUGH 96 HR. IT SHOULD BE NOTED THAT THE TRACK GUIDANCE
STARTS TO DIVERGE AT 120 HR REGARDING HOW QUICKLY LESLIE SHOULD
ENCOUNTER THE WESTERLIES...AND BASED ON THIS SPREAD...THE TRACK
FORECAST CALLS FOR A SLOWER AND MORE NORTHERLY MOTION NEAR THAT
TIME.

THE GLOBAL MODELS SUGGEST THAT LESLIE SHOULD REMAIN IN AN
ENVIRONMENT OF LIGHT/MODERATE EASTERLY SHEAR FOR THE NEXT 36-48
HR...WHICH SHOULD ALLOW FOR GRADUAL DEVELOPMENT. AFTER THAT
TIME...THE CYCLONE IS FORECAST TO ENCOUNTER SIGNIFICANT
SOUTHWESTERLY UPPER-LEVEL WINDS ASSOCIATED WITH THE CUT-OFF
LOW...WHICH IS EXPECTED TO CAUSE ENOUGH SHEAR TO SLOW OR HALT
INTENSIFICATION. THE INTENSITY GUIDANCE IS FORECASTING A LITTLE
LESS STRENGTHENING THAN FOR THE PREVIOUS ADVISORY...MOST NOTABLY
AFTER 48 HR. THE NEW INTENSITY FORECAST IS A BLEND OF THE PREVIOUS
FORECAST AND THE CURRENT SHIPS MODEL...SHOWING LESLIE BECOMING A
HURRICANE BY 24 HR AND SHOWING LITTLE CHANGE IN STRENGTH FROM
72-120 HR.

THE GLOBAL MODELS SHOW THIS SYSTEM BECOMING VERY LARGE...WHICH IS
REFLECTED IN THE CURRENT WIND FIELD FORECAST. AN ADDITIONAL
INCREASE IN SIZE APPEARS LIKELY AFTER 72 HR.


FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 14.7N 46.8W 45 KT 50 MPH
12H 31/1200Z 15.5N 49.0W 55 KT 65 MPH
24H 01/0000Z 16.7N 51.7W 65 KT 75 MPH
36H 01/1200Z 17.9N 54.4W 75 KT 85 MPH
48H 02/0000Z 19.3N 56.8W 80 KT 90 MPH
72H 03/0000Z 22.5N 60.5W 85 KT 100 MPH
96H 04/0000Z 26.5N 61.5W 85 KT 100 MPH
120H 05/0000Z 29.0N 61.5W 85 KT 100 MPH

$$
FORECASTER BEVEN
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1013. WWPR
Quoting tropicfreak:
A few white pixels showing up in Leslie, as she is firing up some very cold cloud tops, also looks like she took a slight dip WSW.


Quoting redwagon:

If so, I doubt the Upper NE will have any compunction as to evacuating, after what they've seen with Isaac and Irene, and the Derecho.
Modify: I don't think the NE will neglect to plan for power outages, floods and trees down this go-around. An Irene-type Leslie wouldn't be something to evacuate about.


100% agree
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TROPICAL STORM LESLIE FORECAST/ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012
0300 UTC FRI AUG 31 2012

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

TROPICAL STORM CENTER LOCATED NEAR 14.7N 46.8W AT 31/0300Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 16 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1002 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT....... 40NE 30SE 0SW 40NW.
12 FT SEAS.. 90NE 45SE 0SW 45NW.
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 14.7N 46.8W AT 31/0300Z
AT 31/0000Z CENTER WAS LOCATED NEAR 14.5N 45.9W

FORECAST VALID 31/1200Z 15.5N 49.0W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 30NE 20SE 0SW 20NW.
34 KT... 70NE 50SE 40SW 70NW.

FORECAST VALID 01/0000Z 16.7N 51.7W
MAX WIND 65 KT...GUSTS 80 KT.
64 KT... 20NE 0SE 0SW 0NW.
50 KT... 50NE 40SE 30SW 40NW.
34 KT...100NE 80SE 50SW 90NW.

FORECAST VALID 01/1200Z 17.9N 54.4W
MAX WIND 75 KT...GUSTS 90 KT.
64 KT... 40NE 30SE 20SW 30NW.
50 KT... 70NE 50SE 40SW 60NW.
34 KT...150NE 120SE 90SW 150NW.

FORECAST VALID 02/0000Z 19.3N 56.8W
MAX WIND 80 KT...GUSTS 100 KT.
50 KT... 70NE 50SE 40SW 60NW.
34 KT...160NE 140SE 100SW 150NW.

FORECAST VALID 03/0000Z 22.5N 60.5W
MAX WIND 85 KT...GUSTS 105 KT.
50 KT... 80NE 60SE 50SW 60NW.
34 KT...180NE 150SE 100SW 150NW.

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 04/0000Z 26.5N 61.5W
MAX WIND 85 KT...GUSTS 105 KT.

OUTLOOK VALID 05/0000Z 29.0N 61.5W
MAX WIND 85 KT...GUSTS 105 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.7N 46.8W

NEXT ADVISORY AT 31/0900Z

$$
FORECASTER BEVEN
Member Since: July 6, 2010 Posts: 113 Comments: 32810
BULLETIN
TROPICAL STORM LESLIE ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012
1100 PM EDT THU AUG 30 2012

...LESLIE CONTINUING TO STRENGTHEN OVER THE OPEN TROPICAL
ATLANTIC...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.7N 46.8W
ABOUT 1010 MI...1625 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES
Member Since: Posts: Comments:
BULLETIN
TROPICAL STORM LESLIE ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012
1100 PM EDT THU AUG 30 2012

...LESLIE CONTINUING TO STRENGTHEN OVER THE OPEN TROPICAL
ATLANTIC...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.7N 46.8W
ABOUT 1010 MI...1625 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES
Member Since: July 6, 2010 Posts: 113 Comments: 32810
Quoting earthlydragonfly:


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


I heart this post so much.
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A few white pixels showing up in Leslie, as she is firing up some very cold cloud tops, also looks like she took a slight dip WSW.

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The eye has really came out, NHC should go with a cat2.
Member Since: March 16, 2012 Posts: 127 Comments: 7972
Quoting pottery:
I'm out>>>>>>>>>

no, that's in... this is out...
<<<<<<<<<<<
lol
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1004. beell
Quoting palmettobug53:
beel?? WOW... long time no see. On the other hand, I don't come in here very often.


bug!!!! I don't post much here but lurk through quite often. I'm so glad we met this evening, my friend.
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Quoting WWPR:


IMO I think you are correct, but for the time being I'm trying to see how close she would get to the northern Islands.

If so, I doubt the Upper NE will have any compunction as to evacuating, after what they've seen with Isaac and Irene, and the Derecho.
Modify: I don't think the NE will neglect to plan for power outages, floods and trees down this go-around. An Irene-type Leslie wouldn't be something to evacuate about.
Member Since: August 4, 2007 Posts: 0 Comments: 3280
breached the levee at Braithwaite to let the water out.

Member Since: June 6, 2010 Posts: 0 Comments: 4458
Quoting HrDelta:


He's looking great. Major Hurricane tomorrow?


Kirk has about 36 to 48 hours left in relatively favorable conditions. If Kirk maintains a clear eye and increase its convection through tomorrow, then it's likely he will become a major hurricane.
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Poor recon seem like they can't get a break
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999. WWPR
Quoting redwagon:

If Leslie doesn't recurve in the next 8 hours, she'll be an East Coast storm... upper East Coast.


IMO I think you are correct, but for the time being I'm trying to see how close she would get to the northern Islands.
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beel?? WOW... long time no see. On the other hand, I don't come in here very often.
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Quoting WWPR:


I hope

If Leslie doesn't recurve in the next 8 hours, she'll be an East Coast storm... upper East Coast.
Member Since: August 4, 2007 Posts: 0 Comments: 3280
This is the bank of the Tangipahoa Dam that they are worried about. Looks small but when you see it from the air it is huge
Member Since: June 6, 2010 Posts: 0 Comments: 4458
Best guess is 100mph at 11pm due to the increased organization since the last TAFB/SAB came in, the eye is really clearing out. CIMSS ADT is up to 87kts.
Member Since: July 8, 2005 Posts: 259 Comments: 24574
Quoting Tazmanian:



Good luck with that.


lol
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993. JLPR2
Back side of the storm is bringing the strongest winds to the buoy.



It does seem the center is around the buoy's latitude, or very close to it, NHC's estimate of 14.5n sounds ok, though I would go with a location very slightly to the south, around 14.2n or 14.3n, the center of the system clearly passed over the buoy.
Member Since: September 4, 2007 Posts: 7 Comments: 8747
Quoting Civicane49:
Kirk's eye has improved over the past several hours.



He's looking great. Major Hurricane tomorrow?
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991. WWPR
Quoting stormchaser19:


at any moment Leslie is going to recurve


I hope
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Quoting stormchaser19:


at any moment Leslie is going to recurve



Good luck with that.
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Quoting Gearsts:
Is west of the nhc track again.


at any moment Leslie is going to recurve
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These past few days in Biloxi have seem like they have lasted a month. All is well in Biloxi, Hwy 90 is clear and the power is on.. I guess it is the price we citizen pay to live in paradise. Prayers go out to the people in Louisana that are flooding.
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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.

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