[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 102314
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU DEC 10 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2245 UTC.

THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N11W 4N23W 4N40W 3N51W. ISOLATED
MODERATE CONVECTION IS FROM 4N-7N BETWEEN 20W-25W. SIMILAR ACTIVITY
IS FROM 1N-4N BETWEEN 27W-30W...AND FROM 4N-6N BETWEEN 38W-40W.

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT BISECTS THE GULF OF MEXICO EXTENDING
ACROSS CENTRAL FLORIDA FROM FORT PIERCE TO FORT MYERS INTO THE GULF
WATERS ALONG 25N86W 24N91W BECOMING STATIONARY TO A 1010 MB LOW IN
THE SW GULF NEAR 21N94W. A SURFACE TROUGH EXTENDS S OF THE LOW INTO
MEXICO TO NEAR 18N92W. OVER FLORIDA...A LARGE TEMPERATURE DIFFERENCE
IS SEEN ACROSS THE FRONTAL BOUNDARY WITH TEMPERATURES IN THE 50S AND
60S OVER N FLORIDA...AND 80S OVER S FLORIDA WITH RECORD HIGH
TEMPERATURES BEING REACHED IN PORTIONS OF S FLORIDA. RADAR IMAGERY
INDICATES A LINE OF SHOWERS/THUNDERSTORMS WITHIN 90 NM N OF THE COLD
FRONT. ISOLATED SHOWERS ARE ALSO NOTED ACROSS PORTIONS OF S FLORIDA
AND THE STRAITS OF FLORIDA. NE SURFACE WINDS UP TO 20 KT IN THE E
GULF...25 KT IN THE NW GULF...ARE BEHIND THE FRONT. THE ENTIRE
SYSTEM IS SUPPORTED BY MOIST WLY FLOW ALOFT BETWEEN A LONGWAVE UPPER
LEVEL TROUGH  DIGGING ACROSS THE ERN CONUS...AND AN UPPER LEVEL
RIDGE CENTERED OVER THE NW CARIBBEAN. EXPECT THE FRONT TO CONTINUING
PUSHING SE ACROSS S FLORIDA TONIGHT...AS THE LOW PRESSURE SYSTEM IN
THE SW GULF MOVES TOWARDS THE NW GULF COAST.

THE CARIBBEAN SEA...
AN UPPER LEVEL RIDGE IS CENTERED OVER THE NW CARIBBEAN ALONG WITH
STRONG SUBSIDENCE AND DRY AIR OVER MUCH OF THE AREA BRINGING
GENERALLY FAIR WEATHER ACROSS THE BASIN. ISOLATED
SHOWERS/THUNDERSTORMS ARE ACROSS THE SW CARIBBEAN AFFECTING PORTIONS
OF NICARAGUA...COSTA RICA...AND PANAMA S OF 13N W OF 79W. THIS AREA
OF ACTIVITY IS DUE TO UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL
RIDGE OVER THE NW CARIBBEAN AND AN UPPER LEVEL TROUGH THAT EXTENDS
OVER THE E/CENTRAL CARIBBEAN FROM THE LEEWARD ISLANDS TO NRN
COLOMBIA. A FEW ISOLATED SHOWERS ARE ALSO NOTED ACROSS THE NRN
CARIBBEAN AFFECTING PORTIONS OF PUERTO RICO...HISPANIOLA...AND CUBA.
FRESH TO STRONG TRADE WINDS ARE ACROSS THE MAJORITY OF THE AREA.
EXPECT MOISTURE ASSOCIATED WITH THE COLD FRONT ACROSS THE GULF OF
MEXICO TO REACH THE NW CARIBBEAN TOMORROW BRINGING A HIGHER CHANCE
OF SHOWERS TO THAT AREA.

THE ATLANTIC OCEAN...
AS OF 2100 UTC...A COLD FRONT EXTENDS ACROSS THE SW N ATLC ENTERING
THE DISCUSSION AREA NEAR 32N71W CONTINUING ALONG 29N77W TO CENTRAL
FLORIDA NEAR FORT PIERCE. ISOLATED SHOWERS ARE WITHIN 90 NM
BEHIND...AND 30 NM AHEAD OF THE FRONT. A FEW ISOLATED SHOWERS ARE
ALSO FARTHER S OF THE BOUNDARY AFFECTING PORTIONS OF S FLORIDA AND
THE NW BAHAMAS. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH
DIGGING ACROSS THE ERN CONUS. THE REMAINDER OF THE W ATLC IS
DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR
29N51W BRINGING GENERALLY FAIR WEATHER TO THE AREA. FARTHER E...A
COLD FRONT ENTERS THE AREA BETWEEN THE AZORES AND CANARY ISLANDS
EXTENDING ALONG 32N25W 26N33W 23N44W. MOST OF THE SHOWER ACTIVITY
ASSOCIATED WITH THE FRONT IS N OF 30N. HOWEVER...ISOLATED SHOWERS
ARE POSSIBLE WITHIN 90NM OF THE FRONT AXIS S OF 30N. THIS FRONTAL
SYSTEM IS SUPPORTED BY A NARROW UPPER LEVEL TROUGH EXTENDING FROM
THE CANARY ISLANDS TO N OF THE CAPE VERDE ISLANDS...THEN W ALONG 20N
TO NEAR 50W.

$$
WALTON



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