[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 212326
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT MAR 21 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
2215 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N9W 2N18W ALONG THE EQUATOR FROM
27W-46W THEN S INTO NE BRAZIL NEAR 1S49W. NO SIGNIFICANT
CONVECTION.

...DISCUSSION...

GULF OF MEXICO...
BROAD DEEP LAYERED TROUGH COVERS THE E US AND THE E GULF OF
MEXICO E OF 90W INTO THE W ATLC WITH MODERATE/STRONG SUBSIDENCE
OVER THE SAME AREA. THE ASSOCIATED COLD FRONT IS IN THE W ATLC.
THE W GULF IS UNDER NEAR ZONAL WESTERLY FLOW. THE SURFACE IS
DOMINATED BY A RIDGE EXTENDING FROM OVER NEW ENGLAND COVERING
THE ENTIRE GULF. SOME UPPER LEVEL MOISTURE IS MOVING ACROSS THE
W GULF IN THE FORM OF THIS HIGH CLOUDS N OF 22N FROM 92W-96W.
THE REMNANTS OF THE FRONT IN THE W ATLC IS SPARKING OFF LOW
LEVEL SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER
THE S FLORIDA PENINSULA AND MOVING INTO THE SE GULF WITHIN 60 NM
OF THE FLORIDA PENINSULA BETWEEN TAMPA AND THE FLORIDA KEYS.
OTHERWISE THE REMAINDER OF THE GULF REMAINS UNDER FAIR WEATHER
CLOUDS THIS EVENING.

CARIBBEAN SEA...
BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED OVER SOUTH
AMERICA AND THE AXIS EXTENDING ALONG 65W INTO THE W TROPICAL
ATLC. A JET STREAM WITH WINDS OF 90 TO 110 KT IS WITHIN 200 NM
OF LINE EXTENDING FROM S OF JAMAICA NEAR 16N78W OVER HISPANIOLA
INTO THE W ATLC INCLUDING PUERTO RICO AND THE VIRGIN ISLANDS.
MODERATE/STRONG EASTERLY TRADE WINDS ARE OVER THE S CARIBBEAN
WITH THE STRONGEST WINDS ALONG THE COAST OF COLOMBIA. THE
TYPICAL NE FLOW OVER THE SW CARIBBEAN IS BANKING LOW LEVEL
CLOUDS WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS INLAND AND WITHIN 90 NM ALONG THE COAST OF W
PANAMA AND COSTA RICA S OF 11N W OF 80W. THE SAME EASTERLY TRADE
WINDS ARE BANKING SIMILAR CLOUDS/ACTIVITY IN THE GULF OF
HONDURAS TO INLAND OVER HONDURAS AND THE YUCATAN S OF 18N W OF
86W. TYPICAL AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS HAVE
DEVELOPED OVER THE JAMAICA...HISPANIOLA...AND PUERTO RICO.
OTHERWISE THE REMAINDER OF THE CARIBBEAN IS UNDER FAIR WEATHER
CLOUDS THIS EVENING.

ATLANTIC OCEAN...
THE DEEP LAYERED TROUGH OVER THE E US AND E GULF OF MEXICO
COVERS THE W ATLC W OF 61W WITH THE ASSOCIATED COLD FRONT
ENTERING THE AREA JUST E OF BERMUDA AND EXTENDING ALONG 27N73W
WEAKENING AS IT REACHES THE FLORIDA COAST NEAR MIAMI. HOWEVER...
IT IS GENERATING LOW LEVEL SCATTERED SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS FROM 25N-28N W OF 79W AND OVER THE N
BAHAMA ISLANDS BETWEEN 76W-79W. EMBEDDED WITHIN THE DEEP LAYERED
TROUGH IS A WEAKENING 1014 MB LOW NEAR 28N66W WITH A SURFACE
TROUGH EXTENDING S ALONG 22N67W THEN SW OVER HISPANIOLA TO
19N72W AND A WEAK WARM FRONT EXTENDING FROM THE LOW ALONG 29N63W
TO 27N61W. THE BROAD UPPER RIDGE THAT COVERS THE CARIBBEAN
EXTENDS INTO THE W AND CENTRAL ATLC NEAR 20N65W THEN NE TO
BEYOND 32N48W. AN EMBEDDED JET STREAM WITH WINDS OF 90 TO 110 KT
EXTENDS WITHIN 200 NM OF A LINE FROM THE CARIBBEAN ACROSS
HISPANIOLA TO 21N59W. UPPER LEVEL DIFFLUENCE TO THE W OF THE
UPPER RIDGE IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 120 NM OF LINE FROM 25N64W TO BEYOND
32N59W. A SECOND DEEP LAYERED TROUGH IS OVER THE E/CENTRAL ATLC
N OF 20N BETWEEN 26W-43W WITH AN ASSOCIATED COLD FRONT ENTERING
THE REGION NEAR 32N34W EXTENDING SW ALONG 26N39W TO 22N46W
BISECTING THE SURFACE RIDGE THAT COVERS MOST OF THE E AND
CENTRAL ATLC. A SURFACE TROUGH EXTENDS FROM THE SURFACE LOW WELL
N OF THE REGION INTO THE AREA THROUGH 32N39W TO 27N46W. BOTH THE
FRONT AND SURFACE TROUGH ARE EMBEDDED WITHIN SOME RATHER DRY
AIR...THUS ONLY LOW LEVEL CLOUDS WITH POSSIBLE ISOLATED SHOWERS
ARE WITHIN 60 NM OF EITHER FEATURE.

$$
WALLACE





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