[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201042
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI APR 20 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 10N14W TO 3N18W WHERE THE ITCZ AXIS CONTINUES S OF THE
EQUATOR NEAR 23W. CLUSTERS OF SCATTERED/MODERATE STRONG
CONVECTION ARE FROM 8N TO JUST S OF THE EQUATOR E OF 14W ACROSS
THE PRIME MERIDIAN INCLUDING SW AFRICA AND FROM 2N TO S OF THE
EQUATOR BETWEEN 14W-21W. CLUSTERS OF SCATTERED/MODERATE STRONG
CONVECTION ARE FROM 4N TO THE EQUATOR BETWEEN 21W-33W.

...DISCUSSION...

GULF OF MEXICO...
NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE GULF THIS MORNING.
A WEAKENING STATIONARY FRONT IS INLAND OVER FLORIDA EXTENDING AT
20/0900 UTC FROM A 1011 MB LOW NEAR TALLAHASSEE FLORIDA SE OVER
THE PENINSULA TO OCALA THEN DISSIPATING TO NEAR SARASOTA. THIS
FRONT IS NOT PRODUCING ANY SHOWER ACTIVITY IN THE GULF OF
MEXICO. A SURFACE TROUGH EXTENDS AT 20/0900 UTC FROM THE
CARIBBEAN OVER THE YUCATAN PENINSULA NEAR 21N88W TO 25N87W.
ISOLATED SHOWERS/THUNDERSTORMS ARE OVER THE SE GULF S OF 27N
BETWEEN 83W-88W. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE
AIR DOMINATE THE UPPER LEVELS OF THE GULF THIS MORNING WITH
MOSTLY CLEAR SKIES ACROSS THE REMAINDER OF THE GULF. THE WEAK
PRESSURE PATTERN ACROSS THE GULF WILL SHIFT E THROUGH EARLY
TONIGHT AS A LOW OVER THE SOUTHERN PLAINS DROPS SE. A COLD FRONT
ASSOCIATED WITH THE LOW WILL ENTER THE NW GULF FRI NIGHT. THE
LOW WILL QUICKLY MOVE ACROSS THE N GULF TO S OF LOUISIANA BY
EARLY SAT WITH THE FRONT EXTENDING TO TAMPICO MEXICO AND THEN
REACH FROM THE BIG BEND AREA OF FLORIDA TO NE YUCATAN BY EARLY
SUN. THE LOW WILL THEN TRACK NE TO ALONG THE SE U.S. COAST
PUSHING THE COLD FRONT TO SE OF THE AREA BY LATE SUN.

CARIBBEAN SEA...
NEAR ZONAL WESTERLY FLOW DOMINATES THE CARIBBEAN THIS MORNING. A
SURFACE TROUGH EXTENDS AT 20/0900 UTC FROM THE GULF OF HONDURAS
NEAR 17N86W OVER THE YUCATAN NEAR 21N88W CONTINUING INTO THE
GULF OF MEXICO. ISOLATED SHOWERS/THUNDERSTORMS ARE OVER THE NW
CARIBBEAN WITHIN 120 NM E OF THE TROUGH THROUGH THE YUCATAN
CHANNEL. A SURFACE TROUGH EXTENDS FROM THE W TROPICAL ATLC INTO
THE SE CARIBBEAN FROM 19N589W THROUGH THE LEEWARD ISLAND JUST S
OF GUADELOUPE TO 11N64W AND COUPLED WITH REMNANT LOW LEVEL
MOISTURE IS GENERATING SCATTERED SHOWERS S OF 18N E OF 61W
ACROSS THE LESSER ANTILLES. REMNANT LOW LEVEL MOISTURE REMAINS
OVER THE CARIBBEAN WITH ISOLATED SHOWERS WITHIN 60/75 NM OF LINE
FROM 15N64W TO 13N80W. THE CONVERGENCE OF LOW LEVEL FLOW FROM
THE E AND UPPER FLOW FROM THE W IS GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS S OF 15N W OF 80W TO INLAND OVER PANAMA
AND COSTA RICA AND WITHIN 60 NM ALONG THE REMAINDER OF THE COAST
OF PANAMA. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER
MOSTLY CLEAR SKIES THIS MORNING. W ATLC SURFACE RIDGE WILL
MAINTAIN MODERATE TO FRESH NE TO E TRADE WINDS OVER THE BASIN
THROUGH THIS EVENING. A COLD FRONT WILL MOVE THROUGH THE GULF OF
MEXICO INTO THE NW CARIBBEAN LATE SAT AFTERNOON OR EARLY
EVENING. THE FRONT WILL THEN WEAKEN AND SLOW DOWN AS IT REACHES
FROM CENTRAL CUBA TO GULF OF HONDURAS SUN THEN FROM E CUBA TO NE
HONDURAS EARLY MON AND FROM NEAR THE WINDWARD PASSAGE TO NEAR
14N82W BY TUE.

ATLANTIC OCEAN...
A SHORTWAVE UPPER TROUGH EXTENDS S ALONG US E COAST FROM NORTH
CAROLINA TO NE FLORIDA WITH A COLD FRONT EXTENDING THROUGH
32N77W TO 31N79W WHERE IT BECOMES A STATIONARY FRONT TO INLAND
OVER THE FLORIDA PANHANDLE. SCATTERED SHOWERS/THUNDERSTORMS ARE
WITHIN 45 NM S OF THE FRONT E OF 80W WITH ISOLATED SHOWERS
WITHIN 45/60 NM OF 79W BETWEEN N OF 27N. NEAR ZONAL WESTERLY
FLOW ALOFT DOMINATES THE REMAINDER OF THE W ATLC. A WEAK SURFACE
RIDGE COVERS THE W ATLC W OF 60W ANCHORED BY A 1018 MB HIGH NEAR
28N69W. A WEAK UPPER TROUGH REMAINS OVER THE CENTRAL ATLC
COVERING THE AREA N OF 18N BETWEEN 40W-60W SUPPORTING A COLD
FRONT THAT ENTERS THE AREA NEAR 32N46W TO 25N48W WHERE IT
DISSIPATES TO 21N54W. SCATTERED SHOWERS ARE WITHIN 150 NM E OF
THE FRONT N OF 28N WITH ISOLATED SHOWERS POSSIBLE WITHIN 90 NM E
OF THE REMAINDER OF THE FRONT. A SURFACE TROUGH EXTENDS FROM THE
W TROPICAL ATLC INTO THE SE CARIBBEAN FROM 19N589W THROUGH THE
LEEWARD ISLAND JUST S OF GUADELOUPE TO 11N64W GENERATING
SCATTERED SHOWERS FROM 11N-19N W OF 50W TO ACROSS THE LESSER
ANTILLES. A BROAD SURFACE RIDGE DOMINATES THE E ATLC N OF 15N E
OF 45W ANCHORED BY A 1025 MB HIGH JUST SW OF THE AZORES. THIS IS
LEAVING THE REMAINDER OF THE ATLC WITH FAIR WEATHER AGAIN THIS
MORNING. W ATLC SURFACE RIDGE WILL MAINTAIN LIGHT TO MODERATE
WINDS ACROSS ENTIRE AREA THROUGH TONIGHT. A STRONG COLD FRONT IS
FORECAST TO MOVE OFF THE SE U.S. AND NE FLORIDA COASTS LATE SAT
NIGHT INTO SUN. THE FRONT WILL REACH FROM 31N78W TO W CENTRAL
CUBA BY SUN AFTERNOON FROM 31N75W TO E CUBA BY EARLY MON AND
BEGIN TO WEAKEN AS IT REACHES FROM 31N68W TO NEAR THE WINDWARD
PASSAGE BY LATE TUE.

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

$$
PAW





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