000
AXNT20 KNHC 072346
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU MAY 07 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 6N10W 2N20W CROSSING THE EQUATOR 
NEAR 25W TO NE BRAZIL NEAR 3S42W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS FROM 2N-6N E OF 19W.

...DISCUSSION...

GULF OF MEXICO...
THE GULF IS DOMINATED BY FAIR WEATHER SUPPORTED BY NWLY FLOW 
ALOFT AND DRY STABLE AIR ON THE E PERIPHERY OF AN UPPER RIDGE 
CENTERED OVER NW MEXICO. AT THE SFC...S TO SE WINDS ARE FAIRLY 
UNIFORM ACROSS THE REGION DUE TO A QUASI-STATIONARY RIDGE AXIS 
EXTENDING FROM THE W ATLC TO THE N GULF COAST. WINDS ARE 
STRONGEST...15-20 KT...OVER THE W WATERS IN RESPONSE TO LOW PRES 
OVER THE SRN PLAINS. LITTLE SIGNIFICANT CHANGE IN THE PATTERN IS 
EXPECTED OVER THE NEXT DAY OR TWO. VISIBILITIES OF 5-7 SM ARE 
BEING REPORTED BY OBSERVATION SITES IN S MEXICO WITH A SMOKE 
PLUME EXTENDING N INTO THE BAY OF CAMPECHE...LIKELY REDUCING 
VISIBILITIES OVER MARINE AREAS AS WELL. 

CARIBBEAN SEA...
SCATTERED TO NUMEROUS SHOWERS AND TSTMS CONTINUE ACROSS THE 
VIRGIN ISLANDS...PUERTO RICO...HISPANIOLA AND NEARBY WATERS N OF 
16N BETWEEN 63W-71W. THIS UNSETTLED WEATHER IS BEING FUELED BY 
STRONG SW FLOW ALOFT AND AN OVERALL DIFFLUENT PATTERN TO THE E 
OF A SHORTWAVE TROUGH. STRONG ELY TRADES AND ASSOCIATED 
LOW-LEVEL WIND SPEED CONVERGENCE IN THIS AREA ARE PROVIDING 
ENHANCED LIFT. LOCALLY HEAVY RAINS ARE POSSIBLE OVER THE 
AFOREMENTIONED ISLANDS. THIS UNSETTLED WEATHER IS EXPECTED TO 
PERSIST FOR AT LEAST THE NEXT 24 HOURS AS THE WX PATTERN HOLDS. 
ELSEWHERE...CONDITIONS ARE GENERALLY QUITE THOUGH ISOLATED 
SHOWERS ARE POSSIBLE JUST ABOUT ANYWHERE...ESPECIALLY OVER THE 
LESSER ANTILLES WHERE THERE IS SHALLOW MOISTURE FETCH STREAMING 
IN FROM THE ATLC. 

ATLANTIC OCEAN...
THERE ARE ONLY A COUPLE OF AREAS OF ACTIVE WEATHER ACROSS THE 
ATLC DISCUSSION AREA THIS EVENING. ONE OF THESE IS OVER AND TO 
THE N OF THE CENTRAL BAHAMAS. SCATTERED SHOWERS AND TSTMS ARE 
FROM 24N-31N BETWEEN 72W-75W. THIS ACTIVITY IS BEING ENHANCED BY 
A SFC TROUGH ALONG 74W AND UPPER DIFFLUENCE E OF A SHORTWAVE 
TROUGH OFF THE GA/FL COAST. THE LOW-LEVEL BOUNDARY WILL LIKELY 
SPLIT AND BECOME DIFFUSE OVER THE NEXT 24 HOURS WHICH SHOULD 
ALLOW MUCH OF THE TSTM ACTIVITY TO DIMINISH. THE OTHER AREA OF 
INTEREST IS S OF 20N BETWEEN 63W-70W...NEAR THE GREATER 
ANTILLES. INSTABILITY AND DIFFLUENCE ALONG AND TO THE E OF 
ANOTHER SHORTWAVE TROUGH IS ENHANCING THIS WEATHER. REFER TO THE 
CARIBBEAN SECTION FOR MORE DETAILS. THE REMAINDER OF THE ATLC IS 
DEVOID OF ORGANIZED DEEP CLOUDINESS SUPPRESSED BY A STABLE 
ATMOSPHERE...ESPECIALLY OVER THE SUBTROPICAL E ATLC WHERE THE 
FLOW IS HIGHLY CONFLUENT. OVER THE TROPICAL E ATLC...A FAIR 
AMOUNT OF CONVECTION IS LOCATED WITHIN THE ITCZ E OF 15W AND 
OVER AFRICA ENHANCED BY BROAD SFC LOW PRES AND AN UPPER RIDGE 
CENTERED NEAR 15N5W. A CONSIDERABLE AMOUNT OF SAHARAN DUST HAS 
SPREAD TO ABOUT 50W...ACCORDING TO THE CIMSS SAL PRODUCT AND THE 
HAZY APPEARANCE ON EARLIER VISIBLE IMAGES. 

$$
CANGIALOSI