[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 042354
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU AUG 04 2011

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.

...TROPICAL WAVES...

A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL TROPICAL ATLC WITH
AXIS ANALYZED FROM 15N35W TO 10N43W...MOVING WNW AT 10-15 KT. A
SLIGHT CURVATURE OBSERVED IN THE LOW/MID LEVEL CLOUDS. NO
ASSOCIATED DEEP CONVECTION IS OBSERVED.

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

THE MONSOON TROUGH EXTENDS WEST FROM THE AFRICAN COAST OF
GUINEA-BISSAU NEAR 12N16W ALONG 11N20W TO 13N30W. THE ITCZ IS
ANALYZED WEST OF THE CENTRAL ATLC TROPICAL WAVE NEAR 11N45W
ALONG 9N53W TO THE ISLAND OF TRINIDAD AND TOBAGO NEAR 11N61W.
ISOLATED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE WITHIN
50 NM ON EITHER SIDE OF THE ITCZ. SCATTERED HEAVY SHOWERS AND
THUNDERSTORMS ARE IN THE VICINITY OF THE MONSOON TROUGH FROM 5N
TO 14N BETWEEN THE COAST OF AFRICA AND 27W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE CENTERED OVER THE SE CONUS BRINGS ANTICYCLONIC
FLOW ACROSS THE GULF THIS EVENING ON WATER VAPOR IMAGERY.
THEREFORE...A DRY SUBSIDENT AIRMASS ALOFT IS SUPPRESSING DEEP
CONVECTION ACROSS THE DISCUSSION AREA...AND LEAVING ONLY A FEW
ISOLATED SHOWERS DOTTING BASIN. AT SURFACE...FAIR WEATHER
CONDITIONS ARE PRESENT THIS AFTERNOON...WITH LIGHT TO MODERATE
ANTICYCLONIC WINDS ANCHORED BY A 1015 MB HIGH NEAR 25N92W. THE
SURFACE RIDGE IS FORECAST TO REMAIN ACROSS THE GULF THROUGH THE
WEEKEND.

CARIBBEAN SEA...
THE CONVECTION ASSOCIATED TO TROPICAL STORM EMILY CLASHED WITH
THE MOUNTAINS OF HISPANIOLA THIS AFTERNOON...AND THE SYSTEM
BECAME A REMNANT TROUGH OF LOW PRESSURE. HOWEVER...A BROAD AREA
OF SCATTERED HEAVY SHOWERS AND THUNDERSTORMS REMAINS OVER THE N
CENTRAL CARIBBEAN N OF 15N BETWEEN 67W-75W INCLUDING INLAND
PORTIONS OF HISPANIOLA. THE NATIONAL METEOROLOGICAL OFFICE IN
DOMINICAN REPUBLIC REPORTED 12-24 HR RAINFALL TOTALS RANGING
FROM LESS THAN ONE INCH TO OVER 7 INCHES ACROSS DIFFERENT
LOCATIONS THROUGHOUT THE COUNTRY. ALTHOUGH THIS SYSTEM IS NO
LONGER A SPECIAL FEATURE...IT CONTINUES TO BE THE PRIMARY FOCUS
ACROSS THE DISCUSSION AREA OVER THE NEXT FEW DAYS. THIS AREA OF
CONVECTION WILL CONTINUE TO MOVE NW ACROSS HISPANIOLA TONIGHT.
ELSEWHERE ACROSS THE CARIBBEAN...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE OVER THE FAR SW BASIN WITHIN 50 NM OFF THE
ACROSS THE COAST OF COSTA RICA...PANAMA...AND COLOMBIA...DUE TO
CLOSE PROXIMITY TO THE MONSOON TROUGH. OTHERWISE...MOSTLY FAIR
WEATHER WITH LIGHT TO MODERATE TRADE WINDS IS OBSERVED ELSEWHERE
ACROSS THE DISCUSSION AREA THIS EVENING.

ATLANTIC OCEAN...
THE CONVECTION ASSOCIATED TO THE REMNANT TROUGH OF LOW PRESSURE
FROM EMILY IS AFFECTING THE ATLC WATERS N OF HISPANIOLA AND E OF
THE BAHAMAS S OF 24N BETWEEN 66W-71W. SCATTERED HEAVY SHOWERS
AND THUNDERSTORMS ROAM THIS AREA. COMPUTER MODELS SUGGEST THIS
AREA OF CONVECTION WILL CONTINUE TO MOVE NE ACROSS THE BAHAMAS
OVER THE NEXT FEW DAYS. A LARGE SURFACE RIDGE DOMINATES THE
REMAINDER OF THE ATLC BASIN...ANCHORED BY A 1029 MB HIGH SW OF
THE AZORES NEAR 33N32W. THIS FEATURE EXTENDS A RIDGE AXIS WSW TO
THE FAR WEST ATLC NEAR THE FLORIDA PENINSULA. THE CIMSS SAHARAN
AIR LAYER TRACKING PRODUCT AND LAST VISIBLE METEOSAT-9 SATELLITE
IMAGERY OF THE DAY SHOWED A LARGE AREA OF AFRICAN DUST FROM
10N-30N BETWEEN 30W-63W. WITHIN THIS AREA OF DRY DUSTY AIR...AN
UPPER LEVEL CYCLONIC CIRCULATION WAS FOUND ON WATER VAPOR NEAR
27N47W WITHOUT ANY CONVECTION.

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

$$

GARCIA



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