[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181153
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI FEB 18 2011

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
1115 UTC.

...ITCZ...
THE ITCZ IS ANALYZED FROM W AFRICA NEAR 6N8W 4N12W 3N19W THEN S
OF THE EQUATOR NEAR 27W INTO SOUTH AMERICA. CLUSTERS OF
SCATTERED MODERATE/STRONG CONVECTION ARE FROM THE EQUATOR TO 4N
BETWEEN 2W-15W. SCATTERED MODERATE CONVECTION IS WITHIN 90/120
NM OF THE ITCZ BETWEEN 20W-22W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE REMAINS OVER THE SE CONUS/W ATLC AND INTO THE
GULF ANCHORED BY A 1028 MB HIGH IN THE W ATLC WITH A WEAK 1024
MB HIGH OFF THE COAST OF FLORIDA NEAR 29N85W. A BROAD UPPER
RIDGE AXIS EXTENDS FROM THE YUCATAN PENINSULA ACROSS NE FLORIDA
GIVING THE GULF W TO SW FLOW ALOFT. STRONG SUBSIDENCE AND DRY
STABLE AIR DOMINATES THE GULF BASIN LEAVING THE AREA WITH MOSTLY
FAIR CONDITIONS AGAIN THIS MORNING. RETURN FLOW AROUND THE
SURFACE RIDGE IS GIVING THE W GULF SOUTHERLY FLOW WHICH IS
BANKING LOW LEVEL CLOUDS OVER THE NW GULF TO INLAND ALONG THE
COAST OF MEXICO N OF VERACRUZ TO OVER TEXAS AND W LOUISIANA.
SURFACE RIDGE WILL CHANGE LITTLE THROUGH MON. A COLD FRONT MAY
APPROACH THE FAR NW WATERS TUE.

CARIBBEAN SEA...
REMNANT SURFACE MOISTURE REMAINS ACROSS THE NW CARIBBEAN AND
CONTINUES TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 60 NM OF LINE FROM PUERTO RICO/MONA PASSAGE
ALONG 16N70W S OF JAMAICA TO NEAR 17N85W. AN UPPER TROUGH DIPS
ACROSS CUBA AND HAITI FROM THE W ATLC LEAVING THE REMAINDER OF
THE CARIBBEAN DOMINATED BY AN UPPER RIDGE ANCHORED IN THE W
TROPICAL ATLC GIVING THE CARIBBEAN S OF 20N SW TO W FLOW ALOFT.
MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATES THE
ENTIRE CARIBBEAN BASIN LEAVING THE REMAINDER OF THE CARIBBEAN
WITH REMARKABLY CLEAR SKIES THIS MORNING. THE EXCEPTION IS SOME
LOW LEVEL CLOUDS WITH ISOLATED SHOWERS BANKING ALONG THE
MOUNTAINS OF W PANAMA TO SE NICARAGUA AND IN THE SW CARIBBEAN
WITHIN 90 NM ALONG THE COAST S OF 13N W OF 81W. SURFACE RIDGE
OVER THE W ATLC WILL DRIFT SLOWLY SE THROUGH SAT. TRADE WINDS
WILL INCREASE SAT NIGHT THROUGH MON AS THIS SURFACE RIDGE
STRENGTHENS.

ATLANTIC OCEAN...
A SURFACE RIDGE COVERS THE W ATLC W OF 45W INTO GULF OF MEXICO
ANCHORED BY A 1028 MB HIGH NEAR BERMUDA. A BROAD UPPER TROUGH
COVERS THE N/CENTRAL ATLC WITH A SHORTWAVE UPPER TROUGH AXIS
EXTENDING INTO THE W ATLC THROUGH 30N60W SW ACROSS CUBA AND
HAITI INTO THE CARIBBEAN TO NEAR 20N75W. THE BROAD UPPER TROUGH
OVER THE N/CENTRAL ATLC SUPPORTS A LINGERING COLD FRONT THAT
ENTERS THE E/CENTRAL ATLC NEAR 32N28W EXTENDING ALONG 27N35W TO
26N39W WHERE IT BECOMES A SHEAR AXIS ALONG 23N54W TO N OF
HISPANIOLA NEAR 20N69W. ISOLATED SHOWERS ARE WITHIN 60 NM E OF
THE FRONT N OF 30N. A BROAD UPPER RIDGE EXTENDS FROM THE W
TROPICAL ATLC NEAR 8N41W NE TO BEYOND 32N16W. DIFFLUENCE ALOFT
COUPLED WITH AN UPPER LEVEL JETSTREAM WITH WINDS OF 90 TO 110 KT
COVERING THE AREA N OF LINE FROM 19N63W TO 25N25W ARE GENERATING
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN
250/300 NM NW OF THE SHEAR AXIS BETWEEN 45W-65W. A WEAK SURFACE
RIDGE COVERS THE E ATLC ANCHORED BY A 1020 MB HIGH NEAR 27N24W
GIVING THE AREA E OF THE FRONT FAIR CONDITIONS AGAIN THIS
MORNING.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
PAW




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