Ed Dunham
Meteorologist & CFHC Forum Moderator
Reged: Sun
Posts: 2088
Loc: Melbourne, FL
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Update - May 25, 7:30PM EDT

With the shear over 94L's western side still in excess of 40 knots, and diffluence spreading out its eastern half like a leaf, trying to find an appropriate description is a challenge. As of this evening, Invest 94L far more closely resembles a Tropical Storm undergoing, and better than half way through, transition, rather than a non-tropical cyclone undergoing tropical transition.
As can be seen in the visible image above, 94L does boast solid convection in its center, but only within a fraction of the center, up at its very top - being ignited and reignited by diffluent southerly winds, and likely less so from a warm core heat engine, which in this cyclone is probably still shallow.
With shear expected to gradually slacken to less unfavorable levels over the weekend, 94L now has very good odds of becoming a named subtropical or tropical storm by this time Sunday, and probably sooner.
Models continue coalescing on a "C" loopy back to the southeast coast, and a bit inland, before ejecting 94L up to the north-northeast and ultimately back out to sea, with a potential 'landfall' somewhere between northeast Florida and North Carolina, which for many could provide beneficial rains, if verified. Intensity probably remains more difficult for the models to get a handle on, but should be limited by 94L's initial subtropical nature, a huge swath of dry air along the southeast to contend with, and limited time over ideally warm waters.
Ciel
Update- May 25th, 546AM EDT

The small dot in the center of the convection May be a Convective Hot Tower, or CHT. I don't recall seeing a CHT in an unnamed system before. With this system I guess anything is possible. Something to keep an eye on. The RBTOP Enhancement is used here to denote the colder colors and the CHT. New enhancement for 2012.
Update - May 25th, 12AM EDT
Weak low is now located just north of the northwestern Bahamas and moving northeast at 16kts. Sustained winds are 35kts to the northeast of the center and central pressure is now 1007mb. All convection remains displaced to the northeast of the center.
Latest model projections suggest that if the high pressure ridge to the north blocks the system and retrogrades it to the west or west northwest the probable area of concern would be farther north along the southeast coast . This would likely keep the heavier precipitation and stronger winds north of the Florida peninsula and more toward the Carolinas. All of this assumes additional strengthening, however, the chances for further development of the system within the next 48 hours to a Subtropical or Tropical Storm has increased to 60 percent.
ED
Original Post - Thursday, May 24th, 4:15PM EDT
The area of low pressure designated as Invest 94L has become better organized since Wednesday evening and at 05/18Z the center was located just southwest of Islandia, Florida, on Elliott Key, with sustained winds close to tropical storm force - mainly offshore to the northeast of the center, however, some locations in extreme South Florida are already experiencing wind squalls gusting to about 50 knots - and with a central pressure of 1008mb. The system is moving to the north northeast at 12 knots and, as high pressure builds to the north of the system, the forward speed is expected to decrease.
The convection is displaced well to the north and east of the center and, like Tropical Storm Alberto earlier this month, the system is influenced by the Gulf Stream SSTs of 27-28C. The shallow system remains beneath the influence of the stronger southwesterly flow at 300mb. Some additional development is possible - probably subtropical in nature. There is a chance that the building high pressure to the north will trap the system and nudge it back toward the Florida peninsula. Frequent showers and thunderstorms are likely over south Florida this evening but the stronger squalls should remain offshore.
If the high pressure increases to the north and indeed blocks the low and retrogrades it back toward the central Florida peninsula, the latter part of the upcoming Memorial Day holiday weekend could get very wet and windy along the Florida east coast. Folks from Florida and the northern Bahamas north to South Carolina should continue to monitor this developing system through the holiday weekend. If the system should attain Subtropical or Tropical Storm status, the next name on the list this year is Beryl.
ED
East Florida Links
Southeast Composite Radar Loop
(Latest Static)
South to North:
Key West, FL Radar Long Range Radar Loop
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Latest Static)
Miami, FL Radar Long Range Radar Loop
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Latest Static)
Melbourne, FL Radar Long Range Radar Loop
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Latest Static)
Jacksonville, FL Radar Long Range Radar Loop
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Caribbean/South East Coast Satellite Imagery
SFWMD Radar Loop of South Florida with storm Track
SFWMD Full Florida Radar Loop with Storm Track
Area Forecast Discussions:
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Jacksonville/Northeast Florida -
94L Event Related Links
Animated Model Plot of 94L
SFWMD Model Plot (Animated Model Plot) SFWMD Hurricane Page
(More Tracking Information)
Clark Evans Track Model Plot of 94L
(Animated!)
Clark Evans Intensity Model Plot of 94L
(Animated!)
Clark Evans Top 10 Analog Storms for 94L
More model runs on from RAL/Jonathan Vigh's page
NRL Info on 94L -- RAMMB Info
Floater Satellite Images:
Visible
(Loop),
IR
(Loop),
WV
(Loop),
Dvorak
(Loop),
AVN
(Loop),
RGB
(Loop),
Rainbow
(Loop),
Funktop
(Loop),
RB Top
Loop)
Edited by cieldumort (Fri May 25 2012 07:55 PM)
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vineyardsaker
Weather Guru
Reged: Wed
Posts: 130
Loc: New Smyrna Beach, FL 29.03N 80.93W
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94L looks poorly formed but I can't help wondering what will happen to it if the high pressure to the north traps the system and nudge it back toward the Florida peninsula and, therefore, keeps it over the Gulf Stream: could 94L get enough energy out of this warm water to form into a TS? Are we not seeing some rotation on the radar already?
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Charley(eyewall), Ivan, Jeanne, Dennis, Wilma
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Ed Dunham
Meteorologist & CFHC Forum Moderator
Reged: Sun
Posts: 2088
Loc: Melbourne, FL
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Actually its had a weak circulation for a couple of days. Right now has it at a 40% probability for additional development, so its worth a close watch for a few days.
ED
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danielw
Moderator
Reged: Wed
Posts: 3384
Loc: Hattiesburg,MS (31.3N 89.3W)
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Up to a 60% chance now. Hmmm
SPECIAL TROPICAL WEATHER OUTLOOK
NWS National Hurricane Center MIAMI FL
840 PM EDT THU MAY 24 2012
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
SATELLITE IMAGES INDICATE THAT THE CLOUD PATTERN ASSOCIATED WITH THE
BROAD AREA OF LOW PRESSURE...LOCATED BETWEEN THE NORTHWESTERN
BAHAMAS AND SOUTHEASTERN FLORIDA...HAS GRADUALLY BECOME BETTER
ORGANIZED THIS AFTERNOON AND EVENING. ENVIRONMENTAL CONDITIONS ARE
EXPECTED TO BECOME MORE CONDUCIVE FOR THE FORMATION OF A
SUBTROPICAL OR TROPICAL CYCLONE BY SATURDAY OVER THE WESTERN
ATLANTIC OCEAN OFF OF THE SOUTHEASTERN UNITED STATES. THIS SYSTEM
HAS A HIGH CHANCE...60 PERCENT...OF BECOMING A TROPICAL OR
SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES
NORTHEASTWARD AT 10 TO 15 MPH.
THIS SYSTEM IS PRODUCING SUSTAINED WINDS OF AROUND 30 MPH WITH WIND
GUSTS OF TROPICAL STORM FORCE...MAINLY TO THE EAST OF THE CENTER
OVER WATER. REGARDLESS OF ANY DEVELOPMENT...LOCALLY HEAVY
RAINFALL...FLOODING...AND GUSTY WINDS ARE STILL POSSIBLE OVER
PORTIONS OF THE NORTHWESTERN AND CENTRAL BAHAMAS...AS WELL AS
CENTRAL CUBA TONIGHT AND TOMORROW. INTERESTS ALONG SOUTHEASTERN
UNITED STATES COAST SHOULD CLOSELY MONITOR THE PROGRESS OF THIS
SYSTEM OVER THE MEMORIAL DAY WEEKEND. ANOTHER SPECIAL TROPICAL
WEATHER OUTLOOK FOR THIS SYSTEM WILL BE ISSUED ON FRIDAY. FOR
ADDITIONAL INFORMATION ON THIS SYSTEM...PLEASE SEE HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...AND PRODUCTS
FROM YOUR LOCAL WEATHER OFFICE.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
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vineyardsaker
Weather Guru
Reged: Wed
Posts: 130
Loc: New Smyrna Beach, FL 29.03N 80.93W
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Quote:
Up to a 60% chance now. Hmmm
Well, at least the models all point away from FL now. Not that I would trust them too much this early. Will wait to see what/when/if the has to say about this one.
-------------------- Motto: chown -R linux:GNU *
Distros: Debian, Xubuntu, Mint
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Charley(eyewall), Ivan, Jeanne, Dennis, Wilma
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danielw
Moderator
Reged: Wed
Posts: 3384
Loc: Hattiesburg,MS (31.3N 89.3W)
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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
1000 PM EDT THU MAY 24 2012
.DISCUSSION...
STORM SYSTEM DeVeLoPinG OVER THE FL STRAITS HAS A CLOSED CIRCULATION
THROUGH THE H100-H70 LYR (1000mb to 700mb-Surface to 10,000ft) CENTERED OVER THE WRN TIP OF GRAND BAHAMA
ISLAND. THIS PLACES THE FL PENINSULA ON THE DESCENDING SIDE OF THE
TROF AXIS...CLEARLY DELINEATED BY THE DEEP MOISTURE ON IR/WV
SATELLITE N OF THE BAHAMAS AND SUBSIDING AIR HUGGING THE COAST.
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danielw
Moderator
Reged: Wed
Posts: 3384
Loc: Hattiesburg,MS (31.3N 89.3W)
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Up to a 70% chance or High at this time....
SPECIAL TROPICAL WEATHER OUTLOOK
NWS National Hurricane Center MIAMI FL
425 AM EDT FRI MAY 25 2012
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
A BROAD AREA OF LOW PRESSURE LOCATED NEAR THE NORTHWESTERN BAHAMAS
IS PRODUCING AN EXTENSIVE AREA OF SHOWERS AND THUNDERSTORMS OVER
THE BAHAMAS AND CUBA. WHILE THE ORGANIZATION OF THIS SYSTEM HAS NOT
IMPROVED OVER THE PAST FEW HOURS...ENVIRONMENTAL CONDITIONS ARE
EXPECTED TO BECOME MORE CONDUCIVE FOR THE FORMATION OF A
SUBTROPICAL OR TROPICAL CYCLONE BY SATURDAY OR SUNDAY. THE LOW
SHOULD MOVE TOWARD THE NORTHEAST AT ABOUT 15 MPH DURING THE NEXT
DAY OR SO...FOLLOWED BY A GRADUAL TURN BACK TOWARD THE WEST ON
SATURDAY. THIS SYSTEM HAS A HIGH CHANCE...70 PERCENT...OF BECOMING
A TROPICAL OR SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS.
LOCALLY HEAVY RAINFALL...FLOODING...AND GUSTY WINDS ARE POSSIBLE
TODAY OVER PORTIONS OF THE NORTHWESTERN AND CENTRAL BAHAMAS...AS
WELL AS CENTRAL CUBA. INTERESTS ALONG THE SOUTHEASTERN UNITED
STATES COAST SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM
OVER THE MEMORIAL DAY WEEKEND. ANOTHER SPECIAL TROPICAL WEATHER
OUTLOOK FOR THIS SYSTEM WILL BE ISSUED LATER TODAY. FOR ADDITIONAL
INFORMATION ON THIS SYSTEM...PLEASE SEE HIGH SEAS FORECASTS ISSUED
BY THE NATIONAL WEATHER SERVICE...AND PRODUCTS FROM YOUR LOCAL
WEATHER OFFICE.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
&&
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE CAN BE
FOUND UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.
$$
FORECASTER LANDSEA/BRENNAN

A large amount of lightning is visible here on the RGB enhancement.
Edited by danielw (Fri May 25 2012 05:57 AM)
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papaswamp
Registered User
Reged: Wed
Posts: 9
Loc: Marineland, FL 29.66N 81.21W
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We certainly could use the rain in N. Florida. Salinity levels for the esutarine waters has been extremely high. Something we don't usually see until July, August (barring any tropical systems).
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danielw
Moderator
Reged: Wed
Posts: 3384
Loc: Hattiesburg,MS (31.3N 89.3W)
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SPECIAL TROPICAL WEATHER OUTLOOK
NWS National Hurricane Center MIAMI FL
845 PM EDT FRI MAY 25 2012
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
SATELLITE PICTURES AND REPORTS FROM NOAA BUOY 41002 INDICATE THAT
THE LOW PRESSURE AREA...CENTERED ABOUT 300 MILES EAST OF CHARLESTON
SOUTH CAROLINA...IS BECOMING BETTER DEFINED AND HAS DEVELOPED
THUNDERSTORM ACTIVITY NEAR THE CENTER. IF CURRENT TRENDS
CONTINUE...ADVISORIES COULD BE INITIATED LATER TONIGHT. THIS SYSTEM
HAS A HIGH CHANCE...NEAR 100 PERCENT...OF BECOMING A SUBTROPICAL OR
TROPICAL CYCLONE DURING THE NEXT 48 HOURS. LITTLE MOTION IS
EXPECTED TONIGHT...BUT A WEST-SOUTHWESTWARD OR SOUTHWESTWARD MOTION
SHOULD BEGIN TOMORROW AND CONTINUE THROUGH SUNDAY. COASTAL
INTERESTS FROM THE CAROLINAS SOUTHWARD THROUGH NORTHEASTERN FLORIDA
SHOULD MONITOR THE PROGRESS OF THIS SYSTEM OVER THE MEMORIAL DAY
WEEKEND. IN ADDITION...LOCALLY HEAVY RAINFALL AND FLOODING WILL
CONTINUE THROUGH AT LEAST TONIGHT OVER PORTIONS OF CENTRAL CUBA AND
THE CENTRAL BAHAMAS. FOR ADDITIONAL INFORMATION ON THIS
SYSTEM...PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE NATIONAL
WEATHER SERVICE...AND PRODUCTS FROM YOUR LOCAL WEATHER OFFICE.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
&&
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE CAN BE
FOUND UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.
$$
FORECASTER KIMBERLAIN/BEVEN
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