[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301043
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON APR 30 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 FROM THE AFRICAN COAST NEAR 08N13W TO
06N17W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N17W TO 03N26W TO 03N37W TO THE EQUATOR NEAR 50W. SCATTERED
MODERATE CONVECTION IS FROM THE EQUATOR TO 07N BETWEEN 23W-39W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH EXTENDS OVER THE EASTERN GULF FROM 29N83W
SOUTH-SOUTHEASTWARD OVER THE FLORIDA STRAITS TO EASTERN CUBA
NEAR 20N76W. WHILE MOST OF THE ACTIVE WEATHER ASSOCIATED WITH
THIS TROUGH CONTINUES TO BE ACROSS THE FLORIDA PENINSULA AND THE
SW NORTH ATLC...A FEW WIDELY SCATTERED SHOWERS ARE OCCURRING
OVER THE FLORIDA STRAITS AND IN THE VICINITY OF THE FLORIDA KEYS
S OF 25N E OF 83W. THE REMAINDER OF THE GULF IS UNDER THE
INFLUENCE OF WEST-NORTHWESTERLY FLOW ALOFT WITH MOSTLY DRY AIR
AND SUBSIDENCE NOTED ON WATER VAPOR IMAGERY BETWEEN 83W-89W. AT
THE SURFACE...A WEAK SURFACE RIDGE AXIS EXTENDS FROM NORTHERN
FLORIDA AND SOUTHERN GEORGIA NEAR 31N84W TO THE TEXAS GULF COAST
NEAR 26N97W. EAST TO SOUTHEAST WINDS IN THE RANGE OF 10 TO 20 KT
ARE EXPECTED THROUGH LATE MONDAY AS A WEAK SURFACE TROUGH...
ANALYZED OVER THE FLORIDA STRAITS AND NW CARIBBEAN SEA MOVES
WEST-NORTHWESTWARD OVER THE NEXT 24 TO 36 HOURS INTO THE CENTRAL
GULF. WHILE THE ECMWF...NAM...AND UKMET HAVE BEEN CONSISTENTLY
SUGGESTING THIS WEAK TROUGHING TO DRIFT WESTWARD...THE GFS HAS
TRENDED LESS AGGRESSIVE WITH FORMING A SURFACE LOW OVER THE
CENTRAL GULF ON MONDAY AND COME MORE INTO LINE WITH THE OTHER
GLOBAL MODEL SOLUTIONS. THEREFORE...THE FORECAST CONTINUES TO
INDICATE THIS TROUGHING WHICH IS EXPECTED TO DISSIPATE BY
TUESDAY OVER THE NW GULF WATERS.

CARIBBEAN SEA...
A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE FLORIDA STRAITS
THIS MORNING AND EXTENDS A TROUGH AXIS SOUTH-SOUTHEASTWARD TO
EASTERN CUBA NEAR 20N76W. WATER VAPOR IMAGERY INDICATES A VERY
DRY AIRMASS IS IN PLACE SOUTHWEST OF THIS UPPER LEVEL TROUGH
AXIS AS WEST-NORTHWESTERLY CONFLUENT FLOW ALOFT DOMINATES N OF
14N W OF 76W. HOWEVER...AS A RESULT OF THE UPPER LEVEL TROUGH...
A WEAK SURFACE TROUGH IS ANALYZED FROM THE FLORIDA STRAITS NEAR
24N81W ACROSS WESTERN CUBA TO 18N83W. A FEW ISOLATED LOW-TOPPED
SHOWERS ARE OCCURRING IN THE VICINITY OF THE SURFACE TROUGH AXIS
AND AREAS EAST FROM 17N-22N BETWEEN 75W-83W...INCLUDING JAMAICA
AND EASTERN CUBA. THIS SURFACE TROUGH IS EXPECTED TO DRIFT
WEST-NORTHWESTWARD OVER THE NEXT 24 TO 36 HOURS INTO THE CENTRAL
GULF OF MEXICO. THE REMAINDER OF THE CARIBBEAN FALLS UNDER THE
INFLUENCE OF SOUTHWEST TO WESTERLY UPPER LEVEL FLOW DUE TO AN
ANTICYCLONIC CIRCULATION CENTERED OVER NE VENEZUELA NEAR 10N63W.
MOST OF THE MIDDLE TO UPPER LEVEL MOISTURE ASSOCIATED WITH THIS
RIDGE IS LOCATED ON THE NORTHWESTERN PERIPHERY THAT CONTINUES TO
PROVIDE HIGH LEVEL CLOUDINESS E OF 73W. AT THE SURFACE...
MODERATE TO FRESH EASTERLIES ARE NOTED ON RECENT OBSERVATIONS
AND EARLIER ASCAT SCATTEROMETER PASSES WHICH ARE FORECAST TO
PERSIST THROUGH WEDNESDAY.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL LOW AND ASSOCIATED TROUGH IS CENTERED
OVER THE FLORIDA STRAITS AND IS PROVIDING MOST OF THE SW NORTH
ATLC WITH PLENTY OF MOISTURE AND OVERCAST CLOUDINESS W OF 60W.
INFRARED SATELLITE IMAGERY INDICATES THAT SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING OVER A LARGE AREA FROM 20N-30N
BETWEEN 62W-81W. THE RIDGE AXIS OVER NORTHERN FLORIDA AND THE SW
NORTH ATLC PRESENT YESTERDAY HAS SLOWLY ERODED AND SHIFTED
EASTWARD AS A WEAK STATIONARY FRONT REMAINS ANALYZED TO THE
NORTH OF THE DISCUSSION AREA ALONG 33N BETWEEN 68W AND THE SOUTH
CAROLINA COAST. OTHERWISE...THE SW NORTH ATLC CONTINUES TO
EXPERIENCE E-SE WINDS IN THE RANGE OF 10 TO 20 KT WITH POSSIBLE
STRONGER WINDS S OF 27N W OF 70W DUE TO THE CLOSE PROXIMITY OF
THE SURFACE TROUGH ACROSS THE FLORIDA STRAITS. FARTHER EAST...AN
UPPER LEVEL LOW IS CENTERED NEAR 27N39W AND CONTINUES TO PROVIDE
SOUTHWESTERLY MIDDLE TO UPPER LEVEL FLOW WITH MOISTURE STREAMING
NORTHEASTWARD FROM THE TROPICS TO THE NORTHEAST AFRICAN COAST.
AT THE SURFACE HOWEVER...A SURFACE RIDGE HOLDS STRONG ANCHORED
BY A 1031 MB HIGH CENTERED NW OF THE AZORES NEAR 43N33W. FRESH
TO STRONG NE WINDS WERE NOTED ON EARLIER ASCAT PASSES OFF THE
COAST OF WESTERN SAHARA STRETCHING TO THE NORTHERN CAPE VERDE
ISLANDS TO 15N30W.

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

$$
HUFFMAN




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