[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040549
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI MAY 04 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 FROM THE AFRICAN COAST NEAR 12N16W TO
TO 06N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N19W TO 06N26W TO 03N41W TO 03N51W. ISOLATED MODERATE
CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 24W-34W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL SHORTWAVE TROUGH IS OVER THE SE CONUS THIS
EVENING WITH AXIS EXTENDING INTO THE NE GULF ALONG 30N86W TO
24N84W. A WEAK SURFACE TROUGH IS ANALYZED FROM 30N86W TO 27N86W
ACROSS THE EASTERN GULF IN ASSOCIATION WITH THIS MIDDLE TO UPPER
LEVEL FEATURE. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATE
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING E OF
86W HOWEVER THIS ACTIVITY CONTINUES TO BE ON A DOWNWARD TREND
DUE TO THE LOSS OF PEAK AFTERNOON AND EARLY EVENING HEATING AND
INSTABILITY. OTHERWISE...THE REMAINDER OF THE GULF BASIN IS
UNDER THE INFLUENCE OF STABLE WEST TO NORTHWEST FLOW ALOFT DUE
TO AN UPPER LEVEL RIDGE WITH AXIS ALONG 95W. HIGH LEVEL MOISTURE
AND CLOUDINESS CONTINUES TO ADVECT EASTWARD OVER FAR PORTIONS OF
THE NW GULF DUE TO ONGOING AND DIMINISHING CONVECTION OVER
INLAND EASTERN MEXICO. MOSTLY EAST TO SOUTHEAST WINDS ARE
OBSERVED IN THE RANGE OF 10 TO 15 KT AS HIGH PRESSURE IS
FORECAST TO BUILD WESTWARD AND ANCHOR ITSELF OVER THE FLORIDA
PENINSULA FRIDAY AND THEN SLIDE FARTHER WEST INTO THE EASTERN
GULF WATERS OVER THE WEEKEND.

CARIBBEAN SEA...
WEST TO SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES ACROSS THE
CARIBBEAN THIS EVENING WITH MOSTLY MIDDLE TO UPPER LEVEL
MOISTURE REMAINING E OF 72W AS AN UPPER LEVEL TROUGH WITH AXIS
FROM 28N67W TO 18N78W CONTINUES TO PROVIDE AMPLE MIDDLE TO UPPER
LEVEL DIFFLUENCE ALOFT. LOW-LEVEL MOISTURE PRESENT EAST OF THIS
TROUGH AXIS OVER THE NE CARIBBEAN COUPLED WITH A SURFACE TROUGH
ANALYZED FROM 20N63W TO 17N68W ARE PROVIDING FOCUS FOR SCATTERED
SHOWERS AND ISOLATED TSTMS N OF 16N E OF 72W...INCLUDING
PORTIONS OF HISPANIOLA...PUERTO RICO...AND THE LEEWARD ISLANDS.
GLOBAL MODEL GUIDANCE HAS CONTINUED TO SUGGEST THAT THE SURFACE
TROUGHING WILL REMAIN NEARLY STATIONARY OVER THE EASTERN
CARIBBEAN THROUGH THE WEEKEND INCREASING THE PROBABILITY OF
SCATTERED SHOWERS AND TSTMS THROUGH THE WEEKEND E OF 75W.
OTHERWISE...THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING
MOSTLY CLEAR SKIES AND FAIR WEATHER CONDITIONS THAT ARE EXPECTED
TO CONTINUE THROUGH THE OVERNIGHT HOURS INTO FRIDAY.

ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL RIDGING IS ANCHORED ACROSS THE EASTERN
U.S. SEABOARD AND THIS MANIFESTS ITSELF AT THE SURFACE WITH A
1020 MB HIGH CENTERED NEAR 30N77W. CLEAR SKIES ARE NOTED OVER
THE REGION N OF 20N W OF 70W. FARTHER EAST...A MIDDLE TO UPPER
LEVEL TROUGH HAS MOVED S OF 30N NEAR 67W AS NOTED ON WATER VAPOR
IMAGERY AND EXTENDS AN AXIS FROM 30N67W TO OVER THE WINDWARD
PASSAGE NEAR 20N74W. THIS TROUGHING SUPPORTS A COLD FRONT
ANALYZED ALONG 30N BETWEEN 54W-68W AND IS GENERATING ISOLATED
SHOWERS WITHIN 90 NM EITHER SIDE OF THE COLD FRONT. THE UPPER
LEVEL TROUGH IS ALSO THE DRIVING FORCE BEHIND SCATTERED SHOWERS
AND ISOLATED TSTMS OCCURRING FROM 18N-22N BETWEEN 56W-70W...NE
OF THE EASTERN CARIBBEAN SEA. THE REMAINDER OF THE EASTERN ATLC
IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1022 MB
HIGH CENTERED NEAR 26N27W.

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

$$
HUFFMAN




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