[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 240000
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU AUG 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2345 UTC.

...SPECIAL FEATURES...

TROPICAL STORM ISAAC IS LOCATED NEAR 16.2N 67.8W AT 24/0000
UTC...MOVING WNW AT 14 KT. THIS POSITION IS ABOUT ABOUT 210
MI...340 KM SE OF SANTO DOMINGO DOMINICAN REPUBLIC. THE MINIMUM
CENTRAL PRESSURE IS 1002 MB. THE MAXIMUM SUSTAINED WIND SPEEDS
ARE 40 KT WITH GUSTS TO 50 KT. PLEASE READ THE FORECAST/ADVISORY
UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 KNHC AND THE PUBLIC
ADVISORY...MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. SCATTERED
MODERATE TO STRONG CONVECTION IS FROM 12N-22N BETWEEN 62W-72W.

TROPICAL STORM JOYCE WAS LOCATED IN THE TROPICAL CENTRAL ATLC
NEAR 15.9N 42.5W AT 23/2100 UTC...MOVING WNW AT 12 KNOTS. THE
ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1006 MB. THE MAXIMUM
SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. PLEASE READ
THE FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25
KNHC AND THE PUBLIC ADVISORY...MIATCPAT5/WTNT35 KNHC FOR MORE
DETAILS. JOYCE IS EXPERIENCING SOUTHERLY WIND SHEAR AND AN
INTRUSION OF DUSTY DRY AIR. SCATTERED MODERATE TO STRONG
CONVECTION IS MOSTLY N OF THE CENTER FROM 17N-23N BETWEEN
41W-48W.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE ERN TROPICAL ATLC EXTENDING FROM THE
COAST OF MAURITANIA NEAR 20N16W TO A 1010 MB LOW OFF THE COAST
OF SENEGAL NEAR 14N20W. THIS SYSTEM IS MOVING WSW AT 5-10 KT. A
THICK LAYER OF SAHARAN DUST SURROUNDS THE WAVE AND ASSOCIATED
LOW...INHIBITING THIS SYSTEM TO GENERATE CONVECTION. AN AREA OF
SCATTERED SHOWERS AND THUNDERSTORMS IS WELL TO THE S FROM 8N-11N
BETWEEN 18W-29W.

...THE ITCZ/THE MONSOON TROUGH...

THE OCEANIC ITCZ AND MONSOON TROUGH ARE PRESENTLY BEING
DISRUPTED BY THE BROAD CYCLONIC WIND FIELD FROM TROPICAL WAVE
AND ASSOCIATED LOW OFF THE CAST OF SENEGAL AND TROPICAL STORM
JOYCE.

...DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL CYCLONIC FLOW COVERS THE BASIN...AS THE BASE OF AN
UPPER TROUGH MOVES ACROSS THE REGION. THIS FEATURE IS PROVIDING
STRONG DIFFLUENCE ALOFT OVER THE NW QUADRANT OF THE BASIN...
GENERATING AN AREA OF SCATTERED SHOWERS AND THUNDERSTORMS N OF
24N W OF 90W. ISOLATED WEAK SHOWERS REMAIN OVER THE WRN BAY OF
CAMPECHE TO THE COASTAL WATERS OF TAMPICO FROM A TROPICAL WAVE
NOW DISSIPATED OVER THE SIERRA MADRE MOUNTAINS. THE REMAINDER OF
THE GULF BASIN IS DOMINATED BY A 1020 MB HIGH CENTERED IN THE NW
COAST OF THE FLORIDA PENINSULA NEAR 29N83W. WHILE WINDS ARE
LIGHT AND VARIABLE OVER THE NE BASIN AND NEAR THE HIGH PRESSURE
CENTER...SSE WINDS UP TO 15 KT ARE FOUND ELSEWHERE S OF 25N W OF
87W. EXPECT CONTINUED CONVECTION OVER THE NW GULF DURING THE
NEXT 24 HOURS.

THE CARIBBEAN SEA...
TROPICAL STORM ISAAC CONTINUES TO BE THE MAIN WEATHER PRODUCER
IN THE CARIBBEAN SEA...GENERATING CONSIDERABLE CONVECTION OVER
THE ERN BASIN. SEE SPECIAL FEATURES SECTION ABOVE FOR MORE
INFORMATION ON THIS SYSTEM. ASIDE ISAAC...THE REMAINDER OF THE
CARIBBEAN IS DOMINATED BY DRY AIR AND SUBSIDENCE ALOFT WRAPPED
AROUND AN ELONGATED UPPER LEVEL LOW CENTERED NEAR 20N78W. ISAAC
WILL CONTINUE TO AFFECT THE CENTRAL AND EASTERN CARIBBEAN OVER
THE NEXT 24 HOURS.

THE ATLANTIC OCEAN...
THE OUTER CONVECTION BANDS ASSOCIATED TO TROPICAL STORM ISAAC
ARE CURRENTLY AFFECTING THE NRN COASTAL WATERS OF PUERTO
RICO...HISPANIOLA...AND TURKS AND CAICOS. SEE SPECIAL FEATURES
SECTION ABOVE FOR MORE INFORMATION ON THIS SYSTEM. ASIDE
TROPICAL STORMS JOYCE AND ISAAC...THE ATLC BASIN DISCUSSION AREA
IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1023 MB HIGH
IN THE ERN BASIN NEAR 37N52W...A 1024 MB HIGH IN THE CENTRAL
BASIN NEAR 33N40W...AND A 1021 MB HIGH IN THE ERN BASIN NEAR
35N22W. THE FAIR WEATHER IS ENHANCED ALOFT BY SAHARAN DUST NOTED
ON METEOSAT-9 PRODUCT. EMBEDDED IN THIS DRY ENVIRONMENT...AN
UPPER LOW WOBBLES NEAR 21N51W. THE CONVECTION ASSOCIATED TO
JOYCE IS EXPECTED TO TRACK NW INTO THE SUBTROPICAL CENTRAL ATLC
N OF 25N OVER THE NEXT 24 HOURS. ALSO...EXPECT WEATHER
CONDITIONS TO DETERIORATE OVER THE NRN COASTAL WATERS OF PUERTO
RICO...HISPANIOLA...TURKS AND CAICOS...AND THE SE BAHAMAS DURING
THE FORECAST PERIOD AS TROPICAL STORM ISAAC APPROACHES THE SRN
BORDER BETWEEN HAITI AND DOMINICAN REPUBLIC.

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

$$

GARCIA




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