[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 250544
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI MAR 25 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ...

ITCZ AXIS IS ANALYZED ALONG 7N11W CROSS THE EQUATOR NEAR 21W
CONTINUING SOUTH OF THE EQUATOR TO INLAND OVER E BRAZIL.
CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 3N TO
S OF THE EQUATOR W OF 25W TO INLAND OVER SOUTH AMERICA. SMALL
CLUSTERS OF SIMILAR CONVECTION ARE WITHIN 90 NM OF 4N BETWEEN
8W-18W.

...DISCUSSION...

GULF OF MEXICO...
THE E GULF IS UNDER NEAR ZONAL WESTERLY FLOW ALOFT WHILE THE W
GULF IS UNDER AN UPPER RIDGE ANCHORED OVER CENTRAL MEXICO WITH
THE RIDGE AXIS EXTENDING ALONG THE TEXAS COAST TO OVER THE LOWER
MISSISSIPPI VALLEY. STRONG SUBSIDENCE AND DRY STABLE AIR COVER
THE GULF WATERS WHILE THE UPPER RIDGE OVER MEXICO IS DRAWING
TROPICAL MOISTURE ALOFT ACROSS MEXICO AND S TEXAS. AS OF 25/0300
UTC A WEAK COLD FRONT EXTENDS FROM THE W ATLC ACROSS NE FLORIDA
S OF JACKSONVILLE TO CEDAR KEY INTO THE GULF OF MEXICO TO 28N86W
WHERE IT BECOMES NEAR STATIONARY TO 27N90W. THIS FRONT IS VOID
OF ANY SHOWER ACTIVITY AND IS DELINEATED BY A SLIGHT WIND SHIFT.
THE SURFACE RIDGE OVER THE W ATLC IS BEGINNING TO SHIFT W OVER
THE SE GULF GIVING THE REMAINDER OF THE GULF S OF 27N MOSTLY
FAIR WEATHER TONIGHT BUT REMNANT LOW LEVEL MOISTURE REMAINS AND
COULD DEVELOP PATCHES OF ISOLATED SHOWERS. DEEP LOW PRESSURE
OVER CENTRAL PLAIN STATES COMBINING WITH STRENGTHENING RIDGE
ACROSS SE GULF COULD RESULT IN INCREASING S RETURN FLOW OVER
GULF WATERS SAT AND SUN.

CARIBBEAN SEA...
BROAD UPPER RIDGE ANCHORED OVER THE TROPICS COVERS MOST OF THE
CARIBBEAN GIVING THE AREA SW TO W FLOW ALOFT. STRONG SUBSIDENCE
AND DRY STABLE AIR COVER ALL BUT THE EXTREME SE CARIBBEAN. FRESH
TO MODERATE EASTERLY TRADE WINDS DOMINATE THE CARIBBEAN. THE
EASTERLY TRADE WINDS COMBINED WITH THE WESTERLY FLOW ALOFT IS
DEVELOPING PATCHES OF SCATTERED SHOWERS OVER THE CARIBBEAN
MAINLY S OF 16N E OF 80W TO OVER THE WINDWARD ISLANDS. FRESH
EASTERLY TRADES ARE EXPECTED TO WEAKEN LATER TODAY THROUGH SAT
AS THE W ATLC RIDGE SHIFTS S. TRADE WINDS WILL BEGIN TO INCREASE
ON SUN.

ATLANTIC OCEAN...
AN UPPER TROUGH IS OVER THE NW ATLC N OF 30N W OF 60W SUPPORTING
A COLD FRONT THAT EXTENDS ALONG 32N TO A 1009 MB LOW NEAR 32N76W
AND A WEAKER COLD FRONT EXTENDING FROM THE LOW SW ACROSS FLORIDA
S OF JACKSONVILLE INTO THE GULF OF MEXICO. SCATTERED SHOWERS ARE
WITHIN 90 NM SE OF THE FRONT E OF THE 1009 MB LOW. A WEAKENING
1017 MB LOW IS IN THE E ATLC NEAR 27N33W WITH A SURFACE TROUGH
EXTENDING E TO 27N24W AND A SECOND SURFACE TROUGH EXTENDING S TO
21N35W. BROAD UPPER RIDGE ANCHORED IN THE TROPICS COVERS THE
REMAINDER OF THE ATLC WATERS WITH A LARGE SURFACE RIDGE
DOMINATING THE ATLC ANCHORED BY A 1023 MB HIGH NEAR 25N44W. THIS
SURFACE RIDGE EXTENDS W TO THE SE GULF OF MEXICO S OF THE W ATLC
FRONTAL BOUNDARY AND HAS A WEAKNESS IN THE E ATLC IN THE
VICINITY OF THE LOW/SURFACE TROUGHS BUT IS GIVING THE ATLC
MOSTLY FAIR WEATHER TONIGHT. W ATLC FRONT WILL SHIFT SE THROUGH
SAT BEFORE DISSIPATING. SURFACE RIDGE WILL REMAIN THROUGH MON.

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

$$
PAW






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