[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200554
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 7N11W ALONG 5N13W 3N16W TO 1N20W WHERE THE ITCZ AXIS
CONTINUES S OF THE EQUATOR NEAR 22W. CLUSTERS OF SCATTERED/
MODERATE STRONG CONVECTION ARE FROM INLAND OVER SW AFRICA TO
JUST S OF THE EQUATOR E OF 13W TO ACROSS THE PRIME MERIDIAN AND
FROM 3N TO S OF THE EQUATOR BETWEEN 13W-21W. SCATTERED/MODERATE
STRONG CONVECTION IS WITHIN 30 NM OF 2N BETWEEN 28W-32W.

...DISCUSSION...

GULF OF MEXICO...
NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE GULF TONIGHT. A
WEAK COLD FRONT IS OVER THE NE GULF AT 20/0300 UTC EXTENDING
FROM A 1011 MB LOW NEAR TALLAHASSEE FLORIDA OVER THE FLORIDA
PENINSULA NEAR OCALA INTO THE GULF AGAIN NEAR SARASOTA TO
27N83W. THIS FRONT IS NOT PRODUCING ANY SHOWER ACTIVITY IN THE
GULF OF MEXICO. A SURFACE TROUGH AT 20/0300 UTC EXTENDS FROM A
LOW IN THE CARIBBEAN OVER THE YUCATAN PENINSULA NEAR 21N88W TO
24N87W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 200 NM E OF
THE TROUGH TO INLAND OVER CUBA AND THE NE YUCATAN. MODERATE TO
STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATE THE GULF BASIN
TONIGHT. A WEAK SURFACE RIDGE IS OVER THE W GULF ANCHORED BY A
1015 MB HIGH OFF THE COAST OF LOUISIANA NEAR 28N91W WITH MOSTLY
CLEAR SKIES ACROSS THE REMAINDER OF THE GULF. SURFACE RIDGE WILL
BUILD OVER THE N GULF AHEAD OF A LOW AND TRAILING FRONT THAT
WILL ENTER THE NW GULF FRI NIGHT. THE LOW WILL SHIFT TO S
LOUISIANA BY EARLY SAT WITH THE FRONT EXTENDING TO TAMPICO
MEXICO AND REACH FROM THE BIG BEND AREA OF FLORIDA TO NE YUCATAN
BY EARLY SUN. THE LOW WILL SHIFT INTO THE CAROLINAS WITH THE
FRONT SE OF THE AREA BY LATE SUN.

CARIBBEAN SEA...
NEAR ZONAL WESTERLY FLOW DOMINATES THE CARIBBEAN TONIGHT. A 1010
MB LOW IS IN THE GULF OF HONDURAS NEAR 17N87W WITH A SURFACE
TROUGH EXTENDING N TO INLAND OVER THE YUCATAN NEAR 19N88W
CONTINUING INTO THE GULF OF MEXICO. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE OVER THE N CARIBBEAN N OF 15N W OF 80W TO
INLAND OVER THE YUCATAN. REMNANT LOW LEVEL MOISTURE REMAINS OVER
THE E CARIBBEAN WITH ISOLATED SHOWERS S OF 17N E OF 68W TO OVER
THE LESSER ANTILLES. THE CONVERGENCE OF LOW LEVEL FLOW FROM THE
E AND UPPER FLOW FROM THE W IS GENERATING SCATTERED SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS S OF 15N W OF 79W TO INLAND OVER
PANAMA AND COSTA RICA LEAVING THE REMAINDER OF THE CARIBBEAN
UNDER MOSTLY CLEAR SKIES TONIGHT. SURFACE RIDGE OVER THE W ATLC
WILL MAINTAIN MODERATE TO FRESH NE TO E TRADE WINDS OVER THE
BASIN THROUGH FRI. THE NEXT COLD FRONT TO MOVE THROUGH THE GULF
OF MEXICO ENTERING THE NW CARIBBEAN LATE SUN THEN STALL AND
BECOME DIFFUSE FROM CENTRAL CUBA TO E HONDURAS BY LATE MON.

ATLANTIC OCEAN...
THE FRONT OVER THE FLORIDA PENINSULA IS GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60/75 NM OF LINE FROM
30N77W TO THE FLORIDA COAST NEAR MELBOURNE. NEAR ZONAL WESTERLY
FLOW ALOFT DOMINATES THE W ATLC. A WEAK SURFACE RIDGE COVERS THE
W ATLC W OF 60W ANCHORED BY A 1018 MB HIGH NEAR 30N72W. AN UPPER
TROUGH REMAINS OVER THE CENTRAL ATLC WEAKENING OVER THE PAST 24
HOURS BUT STILL COVERS THE AREA N OF 18N BETWEEN 40W-60W
SUPPORTING A COLD FRONT THAT ENTERS THE AREA NEAR 32N47W ALONG
26N49W TO 20N54W THE BECOMES A SURFACE TROUGH ALONG 17N58W INTO
THE FAR E CARIBBEAN ACROSS MARTINIQUE TO 12N63W. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 180 NM E OF THE FRONT
N OF 27N AND ISOLATED SHOWERS WITHIN 150 NM E OF THE REMAINDER
OF THE FRONT. SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS ARE OVER THE TROPICAL ATLC S OF 18N BETWEEN 50W
AND THE LESSER ANTILLES BEING ENHANCED BY THE BROAD E/W UPPER
RIDGE THAT DOMINATES THE TROPICAL ATLC E OF 55W. A BROAD SURFACE
RIDGE DOMINATES THE E ATLC N OF 15N E OF 45W ANCHORED BY A 1027
MB HIGH JUST SW OF THE AZORES. THIS IS LEAVING THE REMAINDER OF
THE ATLC WITH FAIR WEATHER AGAIN TONIGHT. SURFACE RIDGE OVER THE
W ATLC WILL PERSIST THROUGH FRI NIGHT. A STRONG COLD FRONT WILL
MOVE OFF THE SE U.S. COAST LATE SUN THE WILL EXTEND FROM 31N67W
TO THE STRAITS OF FLORIDA BY LATE MON AND FROM 31N62W TO CENTRAL
CUBA BY LATE TUE.

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

$$
PAW





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