ATL: DEBBY - Post-Tropical

[ozonepete]

All of the satellite loops look to me like the system as a whole is getting pulled northeastward. The MLC, as AFM said, is clearly getting pulled northeastward now and the main LLC seems to be following it. I just don't see the Euro solution anymore. The NHC discussion for 11PM should be really interesting. This is fascinating stuff. A real learning experience since it is a rare case where two really good models are in such disagreement.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

perhaps the storm just briefly lurches northeast only to reverse and ultimately follow the westward forecast?

Well if it does even a small "lurch" to the northeast as a whole entity it will pretty much have no chance to follow the Euro and go westward. It will have to go northeast, i.e. the GFS forecast solution.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products. Follow us on
Twitter

[ozonepete]

Jonathan, a BIG thank you for all you contribute in helping everyone understand the tropics. You, along with wxman57 and Airforcemet as well as the other professionals make this website such a wonderful place to gather information and we all very much appreciate it!

Absolutely. They are what makes this site so high quality for tracking TCs.

[psyclone]

we'll see how far north the waterspout producing storms can make it. in general, convection has been weakening into light to moderate stratiform rain as it heads north along the coast into the tampa bay region.

[ROCK]

I have it stationary and clearly see the LLC to the left of the cold cloud tower that shot up next to it. Its tilted / sheared whatever you want to call it. I see absolutly nothing that tells me the LLC has relocated to the NE. Not saying it cant but IMO its at 27ish and 87.5ish....and its sitting there.

[johngaltfla]

My thoughts on the current relocation of the low level center of TS Debby. We'll see what the NHC does in a bit, but I am expecting a bump to the right of the 5pm track, and possibly a bump to hurricane at 5 days. Debby is still in the organization phase. Also, if you live in Sarasota or Manatee county...beware. There is an intense area of rain heading N to NNW, and I was tracking waterspouts off the coast.

Trust me, we're seeing those rains now. It's been an unreal amount of rain for the month of June and this is just piling it on.

[cycloneye]

TROPICAL STORM DEBBY FORECAST/ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042012
0300 UTC SUN JUN 24 2012

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE COAST OF LOUISIANA FROM THE MOUTH OF THE PEARL RIVER WESTWARD
TO MORGAN CITY...NOT INCLUDING THE CITY OF NEW ORLEANS OR LAKE
PONTCHARTRAIN

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

TROPICAL STORM CENTER LOCATED NEAR 26.3N 87.5W AT 24/0300Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT IS STATIONARY

ESTIMATED MINIMUM CENTRAL PRESSURE 998 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT.......150NE 150SE 0SW 0NW.
12 FT SEAS..180NE 90SE 0SW 0NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 26.3N 87.5W AT 24/0300Z
AT 24/0000Z CENTER WAS LOCATED NEAR 26.1N 87.5W

FORECAST VALID 24/1200Z 26.7N 87.8W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 40NE 40SE 0SW 30NW.
34 KT...140NE 140SE 30SW 60NW.

FORECAST VALID 25/0000Z 27.0N 88.1W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 40NE 40SE 0SW 30NW.
34 KT...130NE 130SE 50SW 70NW.

FORECAST VALID 25/1200Z 27.1N 88.8W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 40NE 30SE 0SW 30NW.
34 KT...120NE 120SE 60SW 80NW.

FORECAST VALID 26/0000Z 27.2N 89.8W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 40NE 40SE 30SW 40NW.
34 KT...120NE 120SE 80SW 90NW.

FORECAST VALID 27/0000Z 27.2N 91.8W
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 40NE 40SE 30SW 40NW.
34 KT...120NE 120SE 80SW 90NW.

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 28/0000Z 27.2N 93.7W
MAX WIND 70 KT...GUSTS 85 KT.

OUTLOOK VALID 29/0000Z 27.2N 95.2W
MAX WIND 70 KT...GUSTS 85 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 26.3N 87.5W

NEXT ADVISORY AT 24/0900Z

$$
FORECASTER STEWART

[cycloneye]

11 PM advisory forecasts to be a hurricane.See advisory thread.

[CrazyC83]

So we might see Hurricane Debby in the end after all.

[blazess556]

I don't see anything that leads me to believe that the center is relocating to the Northeast. Yes, there is convection firing which gives the illusion that it is moving off to the Northeast. Instead, the center is nearly stationary, directly west of the convection.

[cycloneye]

BULLETIN
TROPICAL STORM DEBBY ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042012
1000 PM CDT SAT JUN 23 2012

...DEBBY REMAINS STATIONARY OVER THE CENTRAL GULF OF MEXICO...
...HEAVY SQUALLS AFFECTING PORTIONS OF WEST-CENTRAL AND
SOUTHWESTERN FLORIDA...


SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...26.3N 87.5W
ABOUT 215 MI...350 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE COAST OF LOUISIANA FROM THE MOUTH OF THE PEARL RIVER WESTWARD
TO MORGAN CITY...NOT INCLUDING THE CITY OF NEW ORLEANS OR LAKE
PONTCHARTRAIN

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

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1000 PM CDT...0300 UTC...THE CENTER OF TROPICAL STORM DEBBY WAS
LOCATED NEAR LATITUDE 26.3 NORTH...LONGITUDE 87.5 WEST. DEBBY HAS
BEEN NEARLY STATIONARY THIS EVENING...AND LITTLE MOVEMENT IS
EXPECTED THROUGH SUNDAY MORNING. A SLOW NORTHWARD MOTION IS
FORECAST TO BEGIN BY SUNDAY AFTERNOON...FOLLOWED BY A GRADUAL
WESTWARD TURN SUNDAY NIGHT OR MONDAY MORNING. ON THE FORECAST
TRACK...THE CENTER OF DEBBY WILL BE MOVING OVER THE NORTHERN GULF
OF MEXICO DURING THE NEXT FEW DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/H...WITH HIGHER
GUSTS. THESE WINDS ARE OCCURRING WELL EAST OF THE CENTER OF
CIRCULATION. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48
HOURS...AND DEBBY COULD BE NEAR HURRICANE STRENGTH BY MONDAY NIGHT.

TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280 KM..
MAINLY NORTHEAST AND EAST OF THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON NEARBY SHIP AND BUOY
REPORTS IS 998 MB...29.47 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO FIRST REACH THE
COAST WITHIN THE WARNING AREA BY SUNDAY NIGHT...MAKING OUTSIDE
PREPARATIONS DIFFICULT OR DANGEROUS.

STORM SURGE...THE COMBINATION OF A STORM SURGE AND THE TIDE WILL
CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY
RISING WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE
GROUND IF THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE...

MISSISSIPPI AND SOUTHEASTERN LOUISIANA...1 TO 3 FT

THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF
ONSHORE FLOW. SURGE-RELATED FLOODING DEPENDS ON THE RELATIVE
TIMING OF THE SURGE AND THE TIDAL CYCLE...AND CAN VARY GREATLY OVER
SHORT DISTANCES. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE
SEE PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE.

RAINFALL...DEBBY IS EXPECTED TO PRODUCE RAIN ACCUMULATIONS OF 3 TO 6
INCHES ALONG THE GULF COAST FROM SOUTHERN LOUISIANA TO THE FLORIDA
PANHANDLE...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 10 INCHES.
ADDITIONAL RAINS OF 1 TO 3 INCHES WITH ISOLATED AMOUNTS UP TO 5
INCHES WILL BE POSSIBLE ACROSS PORTIONS OF THE WESTERN FLORIDA
PENINSULA.

TORNADOES...ISOLATED TORNADOES ARE POSSIBLE OVER PORTIONS OF THE
WEST-CENTRAL AND SOUTHWESTERN FLORIDA PENINSULA TONIGHT AND SUNDAY.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...100 AM CDT.
NEXT COMPLETE ADVISORY...400 AM CDT.

$$
FORECASTER STEWART/LANDSEA

TROPICAL STORM DEBBY FORECAST/ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042012
0300 UTC SUN JUN 24 2012

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE COAST OF LOUISIANA FROM THE MOUTH OF THE PEARL RIVER WESTWARD
TO MORGAN CITY...NOT INCLUDING THE CITY OF NEW ORLEANS OR LAKE
PONTCHARTRAIN

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

TROPICAL STORM CENTER LOCATED NEAR 26.3N 87.5W AT 24/0300Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT IS STATIONARY

ESTIMATED MINIMUM CENTRAL PRESSURE 998 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT.......150NE 150SE 0SW 0NW.
12 FT SEAS..180NE 90SE 0SW 0NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 26.3N 87.5W AT 24/0300Z
AT 24/0000Z CENTER WAS LOCATED NEAR 26.1N 87.5W

FORECAST VALID 24/1200Z 26.7N 87.8W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 40NE 40SE 0SW 30NW.
34 KT...140NE 140SE 30SW 60NW.

FORECAST VALID 25/0000Z 27.0N 88.1W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 40NE 40SE 0SW 30NW.
34 KT...130NE 130SE 50SW 70NW.

FORECAST VALID 25/1200Z 27.1N 88.8W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 40NE 30SE 0SW 30NW.
34 KT...120NE 120SE 60SW 80NW.

FORECAST VALID 26/0000Z 27.2N 89.8W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 40NE 40SE 30SW 40NW.
34 KT...120NE 120SE 80SW 90NW.

FORECAST VALID 27/0000Z 27.2N 91.8W
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 40NE 40SE 30SW 40NW.
34 KT...120NE 120SE 80SW 90NW.

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 28/0000Z 27.2N 93.7W
MAX WIND 70 KT...GUSTS 85 KT.

OUTLOOK VALID 29/0000Z 27.2N 95.2W
MAX WIND 70 KT...GUSTS 85 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 26.3N 87.5W

NEXT ADVISORY AT 24/0900Z

$$
FORECASTER STEWART

[cycloneye]

[Rgv20]

As of the 10pm advisory Debby down to 998mb.

[ROCK]

I didnt see that coming.. ..that ULL is booking it SSW and should be out of the way by tonight. I guess they feel this will allow her to wrap up.....

[Rgv20]

So is the GFS going to budge tonight?

[cycloneye]

11 PM discussion came out late

WTNT44 KNHC 240257
TCDAT4

TROPICAL STORM DEBBY DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042012
1000 PM CDT SAT JUN 23 2012

DEBBY IS GRADUALLY SHOWING SIGNS OF IMPROVED ORGANIZATION AS THE
UPPER-LEVEL SHEAR SHIFTS FROM SOUTHWESTERLY TO MORE OF A SOUTHERLY
COMPONENT. SHIP ZCDJ2 LOCATED ABOUT 80 NMI EAST OF THE CENTER AND
NEAR NOAA BUOY 42003 REPORTED A PRESSURE OF 1001.6 MB AND 38 KT
WINDS AT 24/00Z. BASED ON THIS INFORMATION...THE CENTRAL PRESSURE
IS CONSERVATIVELY ESTIMATED TO BE 998 MB. AIRCRAFT RECONNAISSANCE
DATA AT 23/2020Z INDICATED 850 MB FLIGHT-LEVEL WINDS OF 61 KT IN
THE NORTHEAST QUADRANT...WHICH IS EQUAL TO ABOUT 49 KT SURFACE
WINDS. CONVECTION WAS SOMEWHAT MEAGER AT THAT...BUT SINCE THEN HAS
INCREASED RATHER MARKEDLY IN THAT AREA. THEREFORE THE INITIAL
INTENSITY ESTIMATE IS A SOLID 45 KT.

DEBBY HAS BEEN NEARLY STATIONARY DURING THE PAST 6 HOURS. MULTIPLE
LOW-LEVEL VORTICES HAVE BEEN OUT FROM UNDERNEATH THE EASTERN
SEMICIRCLE CONVECTIVE CLOUD MASS ABOUT A MEAN CENTER OF ROTATION OF
A LARGER GYRE...AND THE LOCATION OF THE LARGER STATIONARY GYRE IS
THE ADVISORY POSITION. ALTHOUGH THERE MAY BE SOME SLIGHT
NORTHEASTWARD MOTION DUE TO REDEVELOPMENT OF THE CENTER CLOSER TO
THE DEEP CONVECTION...THE GENERAL MOTION FOR THE NEXT 24 HOURS OR
SO SHOULD BE SLOWLY POLEWARD. THE LONGWAVE PATTERN ACROSS THE U.S.
HAS A DEEPENING TROUGH OFF THE WEST COAST...WHICH IS CREATING
DOWNSTREAM RIDGING ACROSS THE CENTRAL AND EASTERN UNITED STATES.
THIS INCREASED RIDGING IS REFLECTED BY 20-40 METER 500 MB HEIGHT
RISES AT 00Z ACROSS THE CENTRAL AND SOUTHERN PLAINS...AND EXTENDING
AS FAR EAST AS THE CAROLINA COASTS. THIS BLOCKING RIDGE PATTERN TO
THE NORTH OF DEBBY IS EXPECTED TO GRADUALLY TURN THE CYCLONE
WESTWARD ACROSS THE NORTH-CENTRAL GULF OF MEXICO BY 36-48
HOURS...WITH A CONTINUED WESTWARD MOTION ACROSS THE NORTHWESTERN
GULF AFTER THAT. ALL OF THE AVAILABLE NHC MODEL GUIDANCE...EXCEPT
FOR THE GFS AND GFS-ENSEMBLE MODELS...SUPPORTS THE GENERAL WESTWARD
MOTION SCENARIO. THE MAIN REASON THAT THE GFS MOVES DEBBY EASTWARD
ACROSS THE NORTHEASTERN GULF IS DUE TO IT HAVING A WEAKER AND MORE
VERTICALLY SHALLOW STORM DEPICTED IN THE MODEL. GIVEN THE EXPECTED
FAVORABLE UPPER-LEVEL FLOW PATTERN WITH WEAKER VERTICAL SHEAR
FORECAST TO DEVELOP AFTER 24 HOURS...A DEEPER AND MORE ROBUST
WESTWARD MOVING TROPICAL CYCLONE AS DEPICTED IN THE
ECMWF...UKMET... NOGAPS MODELS SEEMS A MORE REASONABLE SCENARIO.
THE OFFICIAL FORECAST TRACK IS JUST AN UPDATE OF THE PREVIOUS
ADVISORY TRACK.

MODERATE SOUTHWESTERLY VERTICAL WIND SHEAR IS EXPECTED TO GRADUALLY
GIVE WAY TO SOUTHERLY AND EVENTUALLY SOUTHEASTERLY WEAKER WIND
SHEAR BY 36-48 HOURS AS AN UPPER-LEVEL LOW NORTHWEST OF THE CYCLONE
MOVES SOUTHWESTWARD...WHICH ALLOWS DEBBY TO MOVE UNDERNEATH A 200
MB RIDGE AXIS. THE OFFICIAL INTENSITY FORECAST LEANS TOWARD THE
ECMWF MODEL...WHICH IS FORECASTING A HURRICANE CENTRAL PRESSURE BY
96 HOURS...AND IS ABOVE THE GFS-BASED SHIPS AND LGEM MODELS SINCE
THAT OUTPUT LIKELY DOES NOT REPRESENT THE ENVIRONMENTAL CONDITIONS
THAT DEBBY WILL ENCOUNTER. THE OFFICIAL INTENSITY FORECAST IS A
LITTLE HIGHER THAN THE PREVIOUS ADVISORY...AND BRINGS DEBBY TO
HURRICANE STRENGTH BY 72 HOURS.


FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 26.3N 87.5W 45 KT 50 MPH
12H 24/1200Z 26.7N 87.8W 50 KT 60 MPH
24H 25/0000Z 27.0N 88.1W 50 KT 60 MPH
36H 25/1200Z 27.1N 88.8W 55 KT 65 MPH
48H 26/0000Z 27.2N 89.8W 60 KT 70 MPH
72H 27/0000Z 27.2N 91.8W 65 KT 75 MPH
96H 28/0000Z 27.2N 93.7W 70 KT 80 MPH
120H 29/0000Z 27.2N 95.2W 70 KT 80 MPH

$$
FORECASTER STEWART

[WeatherEmperor]

So is the GFS going to budge tonight?

I guess we will find out in roughly 35 minutes when the 00Z runs. Wow, what an epic fail it would be for the GFS if its East solution never materializes...

[SouthDadeFish]

Big convective flare up over the MLC:

[Hurricane Andrew]

NAM is west.

[ozonepete]

Really liked Stewart's 11PM disco and can't argue with his logic. Liked that he explained why the GFS has a northeastward bias and find it hard to argue that the ridging to the northeast will prevent it from going northeastward, even if the center reforms a little more northeastward.

[TropicalAnalystwx13]

MODERATE SOUTHWESTERLY VERTICAL WIND SHEAR IS EXPECTED TO GRADUALLY
GIVE WAY TO SOUTHERLY AND EVENTUALLY SOUTHEASTERLY WEAKER WIND
SHEAR BY 36-48 HOURS AS AN UPPER-LEVEL LOW NORTHWEST OF THE CYCLONE
MOVES SOUTHWESTWARD...WHICH ALLOWS DEBBY TO MOVE UNDERNEATH A 200
MB RIDGE AXIS. THE OFFICIAL INTENSITY FORECAST LEANS TOWARD THE
ECMWF MODEL...WHICH IS FORECASTING A HURRICANE CENTRAL PRESSURE BY
96 HOURS...AND IS ABOVE THE GFS-BASED SHIPS AND LGEM MODELS SINCE
THAT OUTPUT LIKELY DOES NOT REPRESENT THE ENVIRONMENTAL CONDITIONS
THAT DEBBY WILL ENCOUNTER. THE OFFICIAL INTENSITY FORECAST IS A
LITTLE HIGHER THAN THE PREVIOUS ADVISORY...AND BRINGS DEBBY TO
HURRICANE STRENGTH BY 72 HOURS.[/QUOTE]

My thoughts all along..