[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251114
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU DEC 25 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...THE ITCZ...
ITCZ IS CENTERED ALONG 8N10W 4N27W 5N456 3N52W. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 4N-8N BETWEEN 39W-44W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
WITHIN 120 NM S OF THE ITCZ BETWEEN 10W-21W AND WITHIN 120 NM S
OF THE ITCZ W OF 38W TO THE COAST OF SOUTH AMERICA.

...DISCUSSION...

GULF OF MEXICO...
A DEEP LAYERED TROUGH EXTENDS FROM AN UPPER LOW MOVING INTO THE
CANADIAN MARITIMES ACROSS THE NW ATLC AND E US TO OVER THE N
GULF COAST STATES CLIPPING THE FAR NW GULF AS THE ACCOMPANYING
COLD FRONT CONTINUES TO MOVE E EXTENDING OVER SE LOUISIANA
REMAINING STATIONARY AS IT ENTERS THE GULF NEAR 30N92W RUNNING
JUST OFF THE TEXAS COAST THEN INLAND NEAR BROWNSVILLE. SCATTERED
SHOWERS ARE N OF 28N W OF PANAMA CITY FLORIDA AND W OF THE FRONT
TO INLAND OVER TEXAS. THIS WEAK FRONT IS EXPECTED TO PUSH BACK N
AS THE COLD SECTION CONTINUES TO MOVE ACROSS THE N GULF COAST
STATES WITH THE NEXT MAJOR FRONT TO CROSS THE GULF ENTERING LATE
SAT. THE REMAINDER OF THE GULF REMAINS UNDER AN UPPER RIDGE THAT
EXTENDS FROM THE CARIBBEAN AND W ATLC WITH MODERATE/STRONG
SUBSIDENCE AND DRY STABLE AIR NOTED SW OF A LINE FROM THE BIG
BEND AREA OF FLORIDA TO TAMPICO MEXICO. THE SURFACE RIDGE
ANCHORED WELL NE OF BERMUDA GIVES MOST OF THE GULF RETURN FLOW
WITH PATCHES OF LOW CLOUDS AND ISOLATED SHOWERS MAINLY OVER THE
REMAINDER OF THE GULF.

CARIBBEAN SEA...
THE CARIBBEAN REMAINS UNDER THE INFLUENCE OF A BROAD UPPER HIGH
CENTERED IN THE W ATLC OVER THE TURKS AND CAICOS GIVING THE
ENTIRE BASIN ELY UPPER FLOW WITH STRONG SUBSIDENCE AND DRY AIR.
HOWEVER...SHALLOW LOW LEVEL MOISTURE CONTINUES TO STREAM ACROSS
THE CARIBBEAN USHERED IN ON MODERATE/STRONG ELY TRADE WINDS WITH
ISOLATED SHOWERS DOTTING THE ENTIRE CARIBBEAN. THE STRONG HIGH
PRESSURE TO THE N IS EXPECTED TO CONTINUE TO SHIFT E MAINTAINING
THE MODERATE/STRONG TRADE WINDS THROUGH THE WEEKEND DIMINISHING
ON MON.

ATLANTIC OCEAN...
A COLD FRONT DRAPES ACROSS THE ATLC ENTERING THE E/CENTRAL ATLC
NEAR 32N28W EXTENDING SW ALONG 26N37W THEN W TO 25N51W BECOMING
STATIONARY TO 25N57W WHERE IT DISSIPATES OVER THE N AND CENTRAL
BAHAMAS. BROKEN/OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS ARE
WITHIN 90 NM NW OF THE COLD FRONT WITH BROKEN/OVERCAST
STRATOCUMULUS CLOUDS COVERING THE AREA N OF THE FRONT E OF 65W.
A BROAD UPPER LEVEL RIDGE IS ANCHORED OVER THE TURKS AND CAICOS
COVERING THE ENTIRE CARIBBEAN...MOST OF GULF OF MEXICO...AND THE
W ATLC W OF 60W. A BROAD UPPER TROUGH ASSOCIATED WITH THE ABOVE
FRONTAL BOUNDARY IS OVER THE CENTRAL ATLC EXTENDING THROUGH
32N31W THEN AS A SHEAR AXIS W ALONG 26N41W TO 22N58W. THE UPPER
LEVEL TROUGH THAT COVERED THE E ATLC N OF 26N E OF 20W HAS MOVED
NE OUT OF THE REGION WITH A LINGERING SURFACE TROUGH EXTENDING
FROM 32N18W ACROSS THE CANARY ISLANDS TO OFF THE COAST OF
WESTERN SAHARA 24N17W. A WEAK UPPER SHEAR AXIS REMAINS IN THE
TROPICS EXTENDING FROM 18N45W S TO 10N48W. UPPER DIFFLUENCE E OF
THIS UPPER SHEAR AXIS COUPLED WITH AN UPPER RIDGE AMPLIFIED
ALONG 36W TO INLAND OVER THE W AFRICA ENHANCING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS FROM 8N-14N BETWEEN 34W-46W AND
DENSE CLOUD COVER WITH ISOLATED SHOWERS FROM 14N-19N FROM 35W TO
OVER THE CAPE VERDE ISLANDS. MODERATE/STRONG ELY TRADE WINDS
CONTINUE ACROSS THE TROPICAL ATLC AND WILL CONTINUE THROUGH THE
WEEKEND.

$$
WALLACE






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