000 AXNT20 KNHC 082333 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI MAY 08 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 3N20W 1N30W CROSSING THE EQUATOR NEAR 34W TO NE BRAZIL NEAR 3S42W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM N OF THE AXIS BETWEEN 25W-29W. ...DISCUSSION... GULF OF MEXICO... THE GULF IS DOMINATED BY FAIR WEATHER SUPPORTED BY N-NW FLOW ALOFT AND DRY STABLE AIR ON THE ERN PERIPHERY OF AN UPPER RIDGE CENTERED OVER NRN MEXICO. AT THE SURFACE...A QUASI-STATIONARY RIDGE AXIS EXTENDING FROM THE W ATLC TO THE N GULF COAST IS PRODUCING S TO SE WINDS ACROSS THE ENTIRE AREA. SHIP/BUOY OBSERVATIONS AND RECENT SCATTEROMETER PASSES SHOW THE STRONGEST WINDS...15-20 KT...OVER THE WRN WATERS IN RESPONSE TO LOW PRESSURE OVER THE S CENTRAL CONUS. A FRONT IS EXPECTED TO APPROACH THE FAR N WATERS THIS WEEKEND...BUT LATEST MODEL GUIDANCE SUGGESTS THAT IT SHOULD STAY JUST N OF THE GULF WATERS. THIS SHOULD ALLOW FOR A CONTINUATION OF THE MAINLY FAIR WEATHER. CARIBBEAN SEA... SCATTERED SHOWERS AND TSTMS ARE AFFECTING PORTIONS OF PUERTO RICO...HISPANIOLA AND NEARBY COASTAL WATERS. THE LARGE SCALE FORCING CONSISTS OF STRONG SW FLOW ALOFT TO THE E OF A SHORTWAVE TROUGH OVER THE BAHAMAS. HOWEVER...LOCAL EFFECTS ARE ENHANCING THE ACTIVITY AS MUCH OF THE COLDER CLOUD TOPS AND LIGHTNING STRIKES ARE OVER THE ISLANDS. SIMILAR ACTIVITY IS OCCURRING OVER PARTS OF CENTRAL AMERICA...COLOMBIA AND VENEZUELA ENHANCED BY STRONG WLY FLOW ALOFT NEAR THE BASE OF THE UPPER TROUGHING. ELSEWHERE...CONDITIONS ARE GENERALLY TRANQUIL THOUGH ISOLATED SHOWERS ARE POSSIBLE ACROSS THE ENTIRE BASIN... ESPECIALLY OVER THE LESSER ANTILLES WHERE A SHALLOW MOISTURE FETCH IS OBSERVED STREAMING IN FROM THE ATLC. TRADE WINDS ARE MAINLY 15-20 KT...EXCEPT 20-25 KT IN THE TOPOGRAPHICALLY ENHANCED ZONE NEAR THE COAST OF COLOMBIA. LITTLE CHANGE IS EXPECTED IN THIS FLOW OVER THE NEXT COUPLE OF DAYS AS STRONG HIGH PRES REMAINS QUASI-STATIONARY OVER THE CENTRAL ATLC. ATLANTIC OCEAN... THERE ARE ONLY A COUPLE OF SMALL AREAS OF UNSETTLED WEATHER ACROSS THE ATLC DISCUSSION ZONE. ONE OF THESE IS LOCATED MIDWAY BETWEEN BERMUDA AND THE CENTRAL BAHAMAS. LOW-LEVEL CONVERGENCE ALONG A WEAKENING SFC TROUGH AND INSTABILITY ASSOCIATED WITH AN UPPER SHORTWAVE IS PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 26N-29N BETWEEN 73W-75W. THE LOW-LEVEL BOUNDARY IS EXPECTED TO DISSIPATE SHORTLY...LIKELY CAUSING MUCH OF THE ACTIVITY TO DIMINISH LATER TONIGHT. THE OTHER AREA OF DISTURBED WEATHER IS S OF 20N BETWEEN 64W-71W...N OF THE ERN GREATER ANTILLES. INSTABILITY AND DIFFLUENCE ALONG AND TO THE E OF THE AFOREMENTIONED SHORTWAVE IS ENHANCING SCATTERED SHOWERS ACROSS HISPANIOLA...PUERTO RICO AND NEARBY WATERS TO THE N. REFER TO THE CARIBBEAN SECTION FOR MORE DETAILS. THE REMAINDER OF THE ATLC IS VOID OF ORGANIZED DEEP LAYERED CLOUDINESS SUPPRESSED BY A STABLE ATMOSPHERE...ESPECIALLY OVER THE SUBTROPICAL E ATLC WHERE THE FLOW IS HIGHLY CONFLUENT. OVER THE TROPICAL E ATLC...MUCH OF THE STRONG CONVECTION NOTED YESTERDAY HAS DIMINISHED. A CONSIDERABLE AMOUNT OF SAHARAN DUST HAS SPREAD TO ABOUT 50W...ACCORDING TO THE CIMSS SAL PRODUCT. $$ CANGIALOSI