[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 022346
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON FEB 02 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
2315 UTC.

...THE ITCZ...

THE ITCZ IS CENTERED ALONG 8N9W 3N20W CROSSING THE EQUATOR AT
33W AND INTO NE BRAZIL NEAR 3S44W. SCATTERED MODERATE CONVECTION
IS FROM THE EQUATOR TO 5N BETWEEN 15W-30W. NUMEROUS STRONG
CONVECTION IS NEAR THE NE BRAZIL COAST FROM 5S TO THE EQUATOR
BETWEEN 40W-46W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT ACROSS THE CENTRAL GULF OF MEXICO
EXTENDS SW FROM NEAR FT WALTON BEACH FL ACROSS THE WRN GULF AND
ENTERS MEXICO S OF TAMPICO. THE FRONT IS BEING SUPPORTED BY A
DEEP LAYERED TROUGH LOCATED ACROSS THE ERN CONUS. NORTHERLY GALE
FORCE WINDS OF 25 TO 35 KTS ARE CURRENTLY ANALYZED N OF THE
FRONT TO 23N W OF 93W. THESE WINDS ARE EXPECTED TO CONTINUE FOR
THE NEXT 18 TO 24 HOURS. SCATTERED SHOWERS AND ISOLATED TSTMS
ARE WITHIN 120 NM E OF THE FRONT ACROSS THE COASTAL SE U.S. AND
WRN GULF. E OF THE FRONT...A 1009 MB LOW IS CENTERED NEAR
27N84W. A WARM FRONT EXTENDS FROM THE LOW EASTWARD ACROSS
CENTRAL FL FROM TAMPA TO NEAR MELBOURNE. ALSO A SURFACE TROUGH
EXTENDS S FROM THE LOW ACROSS THE ERN GULF AND THEN EXTENDS W
ACROSS THE CENTRAL GULF TO NEAR 23N92W. MIDDLE TO UPPER LEVEL
DIFFLUENCE AHEAD OF THE AFOREMENTIONED UPPER TROUGH ALONG WITH
LOW-LEVEL SURFACE CONVERGENCE ARE AIDING IN SUPPORTING A
DEVELOPING SQUALL LINE FROM NEAR LAKE OKEECHOBEE FLORIDA THROUGH
THE DRY TORTUGAS TO COZUMEL MEXICO. THE PRESENCE OF THE SQUALL
LINE WAS SUPPORTED BY RADAR AND LIGHTNING DATA. THIS SQUALL LINE
IS EXPECTED TO MOVE THROUGH SOUTH FLORIDA AND NW CUBA OVER THE
NEXT SEVERAL HOURS. OVER THE NEXT 6 HOURS...THE SFC LOW WILL
CONTINUE TO MOVE NE ACROSS THE FLORIDA PENINSULA AND WILL ENTER
THE W ATLANTIC.

CARIBBEAN SEA...
ZONAL UPPER LEVEL WESTERLY FLOW IS OBSERVED ACROSS THE NW
CARIBBEAN SEA WHILE AN UPPER LEVEL RIDGE EXTENDS FROM NRN
COLOMBIA NE ACROSS PUERTO RICO AND THE LEEWARD ISLANDS. MODERATE
TO STRONG SUBSIDENCE AND DRY AIR DOMINATES THE MIDDLE AND UPPER
LEVELS OF THE ATMOSPHERE. AT THE SURFACE...A RELATIVELY TIGHT
PRESSURE GRADIENT BETWEEN A WRN ATLC HIGH AND A 1009 MB
COLOMBIAN LOW IS GENERATING MODERATE TO FRESH TRADES ACROSS THE
BASIN. LOW-LEVEL SPEED CONVERGENCE OF THESE TRADES ARE PRODUCING
POSSIBLE SHOWERS OVER THE SE CARIBBEAN S OF 13N E OF 67W AND
ALSO ACROSS THE SW CARIBBEAN WITHIN 90 NM OF THE PANAMA AND
COSTA RICA COASTLINES. THE SQUALL LINE MENTIONED IN THE GULF
SECTION IS ENTERING THE YUCATAN CHANNEL AS OF 2100 UTC...AND IS
EXPECTED TO PUSH FURTHER INTO THE NW CARIBBEAN OVER THE NEXT
SEVERAL HOURS.

ATLANTIC OCEAN...
UPPER LEVEL DIFFLUENCE E OF THE UPPER TROUGH DIGGING SOUTHWARD
OVER THE ERN CONUS WAS NOTED ACROSS THE WRN ATLC W OF 70W.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE INDICATED OVER MUCH OF
FLORIDA AND INTO THE W ATLC WATERS N OF 25N AND W OF 80W AS A
RESULT. THE NORTHERN PART OF THE AFOREMENTIONED SQUALL LINE IS
EXPECTED TO CROSS S FLORIDA AND ENTER THE EXTREME SW PORTION OF
THE ATLANTIC NEAR THE WRN BAHAMAS OVER THE NEXT FEW HOURS. ALSO
THE PREVIOUSLY MENTIONED SURFACE LOW PRESSURE CENTER IN THE ERN
GULF IS FORECAST TO MOVE NE ACROSS FLORIDA AND INTO THE FAR W
ATLC OVER THE NEXT 6 HOURS. A DEEP LAYERED TROUGH LOCATED WELL N
OF THE DISCUSSION AREA OVER THE N-CENTRAL ATLC SUPPORTS A COLD
FRONT THAT ENTERS THE AREA NEAR 32N35W AND EXTENDS SW TO 28N45W
AND THEN CONTINUES AS A DISSIPATING STATIONARY FRONT THROUGH
22N65W. SCATTERED SHOWERS ARE WITHIN 90 NM AHEAD OF THE FRONT
AND 120 NM BEHIND THE FRONT. A 1031 MB SURFACE HIGH IS CENTERED
N OF THE AREA NEAR 35N53W. A RIDGE EXTENDS SW FROM THE HIGH TO
THE CENTRAL BAHAMAS AND W CUBA. RELATIVELY TRANQUIL WEATHER
CHARACTERIZED BY VERY DRY AIR ALOFT IS NOTED OVER THE REMAINDER
OF THE ATLANTIC WITH A WEAK DISSIPATING 1024 MB SURFACE HIGH
CENTERED NEAR 26N40W. ALOFT...AN UPPER LEVEL RIDGE AXIS EXTENDS
FROM THE NE CARIBBEAN INTO THE CENTRAL ATLC THROUGH 21N50W TO
NEAR 22N30W. AN UPPER LEVEL LOW CENTERED NEAR 12N45W IS
UNDERCUTTING THE RIDGE AXIS NOTED ABOVE.

$$
WALTON/COBB



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