[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231811
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN OCT 23 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM
THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON
SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...SPECIAL FEATURES...

THE CENTER OF CATEGORY TWO HURRICANE WILMA AT 23/1800 UTC IS
NEAR 23.1N 85.3W OR ABOUT 210 NM/390 KM WEST-SOUTHWEST OF KEY
WEST FLORIDA...AND ABOUT 260 NM/485 KM SOUTHWEST OF THE
SOUTHWESTERN COAST OF THE FLORIDA PENINSULA. WILMA IS MOVING
NORTHEASTWARD 10 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS
963 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 85 KT WITH GUSTS TO
105 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER
AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE WELL TO THE NORTH
OF THE CENTER...FROM 25N TO 26N BETWEEN 84W AND 86W...AND FROM
23N TO 25N BETWEEN 85W AND 87W...AND FROM 21N TO 23N BETWEEN 85W
AND 87W. OVERCAST MULTILAYERED CLOUDS AND OTHER SHOWERS AND
THUNDERSTORMS COVER THE GULF OF MEXICO EAST OF THE LINE FROM
30.3N 87W AT THE FLORIDA PANHANDLE TO 27N91W TO 22N92W TO
19N92W. OVERCAST HIGH CLOUDS FROM WILMA ARE SHOOTING WELL
NORTHEASTWARD AS FAR AS 37N60W AND 37N50W...THEN CURVING
SOUTHEASTWARD AFTER THAT. SURFACE SOUTHERLY WINDS ARE BLOWING
TOWARD WILMA FROM AS FAR AWAY AS THE CARIBBEAN SEA WEST OF 80W.
BROKEN TO OVERCAST HIGH CLOUDS ARE CURVING SOUTHWESTWARD...WEST
OF 21N81W 18N83W 16N84W. SURFACE WINDS NORTH OF 20N WEST OF 70W
ARE SOUTHERLY... PARTLY DUE TO HURRICANE WILMA...AND PARTLY DUE
TO THE SURFACE RIDGE. IT IS POSSIBLE THAT WILMA WILL HIT THE
SOUTHWESTERN COAST OF FLORIDA AS EITHER A CATEGORY 2 OR CATEGORY
1 HURRICANE MONDAY MORNING.

TROPICAL STORM ALPHA HAS WEAKENED TO A TROPICAL DEPRESSION AT
23/1500 UTC AS IT HAS MOVED OVER AN AREA NEAR THE HAITI/DOMINICAN
REPUBLIC BORDER. THE FLOW AROUND THE SURFACE CENTER HAS BECOME
DISRUPTED AS IT IS IN CONTACT WITH THE MORE MOUNTAINOUS AREAS OF
HISPANIOLA. THE POORLY-DEFINED CENTER OF TROPICAL DEPRESSION
ALPHA AT 23/1800 UTC IS NEAR 19.8N 72.8W OVER THE NORTHWESTERN
TIP OF HAITI AND ABOUT 87 NM/160 KM SOUTH-SOUTHEAST OF GREAT
INAGUA ISLAND IN THE BAHAMAS. ALPHA IS MOVING NORTH-NORTHWEST
13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. THE
MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KT WITH GUSTS TO 40 KT.
SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT5/WTNT25 KNHC AND THE PUBLIC ADVISORY UNDER HEADERS
MIATCPAT5/WTNT35 KNHC FOR MORE DETAILS. IT IS POSSIBLE THAT
ALPHA WILL STRENGTHEN AGAIN AS IT PASSES OVER THE WATERS NORTH
OF HISPANIOLA. A LARGE-SCALE UPPER LEVEL RIDGE IS ON TOP OF
ALPHA. SHOWERS AND THUNDERSTORMS ARE SPREAD OUT...STRETCHING
FROM THE COAST OF VENEZUELA NEAR 11.5N 68.6W TO THE SOUTHEASTERN
DOMINICAN REPUBLIC. SCATTERED MODERATE TO ISOLATED STRONG
SHOWERS AND THUNDERSTORMS ARE BETWEEN 68W AND 71W FROM VENEZUELA
NORTHWARD TO 17N/18N...AND THEN ALSO EXTEND TO 21N BETWEEN 68W
AND 75W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS
ALSO IN THE CARIBBEAN WATERS FROM THE VENEZUELA/COLOMBIA BORDER
NORTHWARD TO SOUTHERN HAITI. ALPHA IS EXPECTED TO PRODUCE TOTAL
RAIN ACCUMULATIONS OF 4 TO 8 INCHES IN MUCH OF HISPANIOLA...WITH
POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 15 INCHES IN MOUNTAINOUS
TERRAIN. THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS
AND MUD SLIDES.

...TROPICAL WAVES...

AN EAST ATLANTIC OCEAN TROPICAL WAVE IS ALONG 33W/34W SOUTH
OF 16N MOVING WEST 10-15 KT. BROKEN TO OVERCAST HIGH CLOUDS
ARE NORTH OF THE WAVES FROM 13N TO 19N BETWEEN 25W AND 44W...
BEING BLOWN TO THE EAST BY THE UPPER LEVEL WESTERLY FLOW ON
THE SOUTHERN SIDE OF A TROUGH. SCATTERED MODERATE TO ISOLATED
STRONG SHOWERS AND THUNDERSTORMS FROM THE ITCZ ARE BEING PUSHED
NORTHWARD A BIT FROM 9N TO 11N BETWEEN 31W AND 38W.

A CENTRAL ATLANTIC TROPICAL WAVE IS ALONG 47W SOUTH OF 17N
MOVING WEST 10 TO 15 KT. THIS WAVE ALSO IS UNDER THE INFLUENCE
OF STRONG WESTERLY SHEAR...WITH THE SAME TROUGH AS THE 33W/34W
TROPICAL WAVE. WARMING CLOUD TOP TEMPERATURES WITH POSSIBLY
WEAKENING BUT STILL LINGERING ITCZ SHOWERS AND THUNDERSTORMS
FROM 8N TO 11N BETWEEN 40W AND 50W.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 81W SOUTH OF 16N
MOVING WEST 15 KT. IT IS POSSIBLE THAT THE WIDELY SCATTERED
MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 10N TO
14N BETWEEN 77W AND 83W ARE RELATED TO THIS WAVE.

...ITCZ...

ITCZ 11N14W 6N20W 8N30W...9N35W 12N44W...10N49W 10N60W 11N63W.
CONVECTIVE ACTIVITY AWAY FROM THE TROPICAL WAVES...SCATTERED
MODERATE TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS ELSEWHERE
FROM THE EQUATOR TO 10N BETWEEN 10W AND 40W.

...DISCUSSION...

THE REST OF THE GULF OF MEXICO AWAY FROM HURRICANE WILMA...
A COLD FRONT STRETCHES FROM THE FLORIDA EAST COAST NEAR
TITUSVILLE TO CLEARWATER ON THE WEST COAST...INTO THE GULF OF
MEXICO TO 26N87W AND 23.5N90W...TO 20N91.5W TO THE NORTHERN
ISTHMUS OF TEHUANTEPEC TO WEST OF THERE NEAR 19N97.5W. THIS
FRONT IS NOT APPARENT IN VISIBLE SATELLITE IMAGERY. IT HAS BEEN
MORE APPARENT IN STUDYING THE TEMPERATURE AND DEWPOINT DATA FROM
STATIONS DURING THE LAST SEVERAL HOURS. IT IS EASILY POSSIBLE
THAT THIS FRONT WILL BECOME STATIONARY SOON. MIDDLE TO UPPER
LEVEL DRY AIR AND MIDDLE LEVEL WESTERLY WIND FLOW COVER THE REST
OF THE GULF WATERS. THE DEEP LAYER TROUGH WHICH IS GOING TO KICK
WILMA TOWARD FLORIDA HAS BEEN SWINGING SOUTHEASTWARD. ONE OF THE
LOBES OF ENERGY OF THE TROUGH IS OVER THE CENTRAL PLAINS STATES
NOW...MOVING SOUTHEASTWARD...GETTING READY FOR THE BIG PUSH
TOWARD THE NORTHEAST.

THE REST OF THE CARIBBEAN SEA AWAY FROM HURRICANE WILMA...
DEEP CONVECTION ON THE SE SIDE OF HURRICANE WILMA CONTINUES TO
AFFECT PARTS OF THE FAR NW CARIBBEAN AND THE YUCATAN
CHANNEL...BUT THE WORST CONDITIONS ARE NOW BEGINNING TO LIFT N
OF THE AREA. THE UPPER LEVEL FLOW OVER THE CARIBBEAN IS RATHER
COMPLEX ALTHOUGH GENERALLY SPEAKING IT IS DOMINATED BY
SUBSTANTIAL EASTERLY FLOW FROM THE 67W TO 80W...AND THEN SPLITS
N ACROSS THE CAYMAN ISLANDS AND SW TOWARDS CNTRL AMERICA INTO
THE OUTFLOW JETS OF HURRICANE WILMA. TROPICAL STORM ALPHA IS
CLOSE TO MAKING LANDFALL ON THE S COAST OF THE DOMINICAN
REPUBLIC. SEE SPECIAL FEATURES FOR FURTHER DISCUSSION. NORTHERLY
UPPER FLOW LIES ACROSS THE LESSER ANTILLES ON THE W SIDE OF A
LARGE UPPER TROUGH OVER THE CNTRL ATLC. ABUNDANT MOISTURE IS
POOLED OVER THE E CARIBBEAN...RESULTING IN WIDESPREAD CLOUDINESS
AND SCATTERED SHOWERS...BUT A PUNCH OF DRIER AIR IS EXPECTED TO
MOVE IN FROM THE ATLC SUN NIGHT AND MON AND WILL PUSH THE
WETTEST WEATHER WWD TO THE W CARIBBEAN BY MID-WEEK.

THE ATLANTIC OCEAN...
THE COLD FRONT WHICH RUNS FROM FLORIDA INTO THE GULF OF MEXICO
STARTS FROM A 1006 MB SURFACE LOW PRESSURE CENTER NEAR 31.5N78W
TO THE FLORIDA COAST NEAR TITUSVILLE. A SURFACE TROUGH IS ALONG
33N67W TO 28N73W. CLOUDS AND SHOWERS ARE WITHIN 200 NM NORTH AND
NORTHWEST OF THE TROUGH. A SURFACE TROUGH TRAILS A 1016 MB LOW
PRESSURE CENTER NEAR 31N47W TO 29N50W AND 28N57W. A COLD FRONT
IS WELL NORTH OF THE AREA BETWEEN 40W AND 50W. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE FROM 30N TO 35N BETWEEN 35W AND 46W.
LOW CLOUDS WITHIN 60 TO 90 NM ON EITHER SIDE MARK THE TROUGH.
A SURFACE RIDGE COVERS THE REST OF THE ATLANTIC WATERS...FROM
A 1023 MB HIGH PRESSURE CENTER NEAR 34N18W TO 30N25W 26N39W
25N55W 25N70W. UPPER LEVEL ANTICYCLONIC FLOW FROM WILMA SHOOTS
EASTWARD INTO THE ATLANTIC OCEAN AND EVENTUALLY CURVES TO
30N43W...BEFORE HOOKING TO THE SOUTHWEST AND GOING TOWARD THE
CENTRAL PART OF THE EASTERN CARIBBEAN SEA ISLANDS...TOWARD THE
BASE OF A SOUTHERN ATLANTIC OCEAN TROUGH. THE TROUGH APPEARS TO
RUN FROM A LOW CENTER NEAR 16N44W TO THE EASTERN CARIBBEAN SEA
NEAR 14N66W. MIDDLE TO UPPER LEVEL DRY AIR IS WITHIN 280 NM ON
EITHER SIDE OF 15N66W 17N53W 22N37W. ANOTHER TROUGH IN THE
EASTERN ATLANTIC OCEAN IS DIGGING TO 20N30W EXTENDING
NORTHEASTWARD BEYOND 30N20W.

$$
MT

This weather bulletin was brought to you by:
www.nashvilleweather.net