000 AXNT20 KNHC 110546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUN 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS FROM 11N47W TO 1N51W MOVING W 15 KT. THE WAVE COINCIDES WITH THE LEADING EDGE OF THE DEEP MOISTURE MAXIMUM IN THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 150/180 NM OF THE WAVE AXIS N OF 5N. TROPICAL WAVE IS OVER THE W CARIBBEAN AND CENTRAL AMERICA ALONG 85W S OF 19N MOVING W 15 KT. WAVE IS BENEATH AN UPPER TROUGH AND DRY STABLE AIR THAT COVERS THE NW CARIBBEAN...THUS NO SHOWER ACTIVITY IS ASSOCIATED WITH THIS WAVE IN THIS BASIN. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N12W 5N25W 3N36W 7N48W INTO SOUTH AMERICA NEAR THE BORDER OF FRENCH GUIANA AND SURINAME. SCATTERED MODERATE/STRONG CONVECTION IS FROM 5N-6N BETWEEN 11W-18W INCLUDING PORTIONS OF LIBERIA/SIERRA LEONE AND FROM 4N TO THE COAST OF SW AFRICA E OF 4W ACROSS THE PRIME MERIDIAN. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM N OF THE ITCZ AXIS BETWEEN 30W-36W. ISOLATED CLUSTERS OF SIMILAR CONVECTION ARE WITHIN 120 NM OF THE ITCZ AXIS FROM 18W-30W. ...DISCUSSION... GULF OF MEXICO... THE GULF REMAINS RATHER TRANQUIL TONIGHT AS DRY STABLE AIR DOMINATES THE AREA. SOME LATE AFTERNOON THUNDERSTORMS THAT DEVELOPED INLAND OVER FLORIDA HAVE MOVED S OVER THE FLORIDA STRAITS GIVING THE FLORIDA KEYS SOME SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS. A WEAK 1016 MB HIGH IS CENTERED SSE OF THE MOUTH OF THE MISSISSIPPI RIVER NEAR 27N88W. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER CENTRAL MEXICO COVERING THE W GULF WHILE AN UPPER TROUGH OVER THE W ATLC COVERS THE REMAINDER OF THE E GULF. EXPECT THE FAIR WEATHER TO CONTINUE OVER MOST OF THE GULF DURING THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE FAR W CARIBBEAN...SEE ABOVE. A 1008 MB LOW IS IN THE SW CARIBBEAN NEAR 12N77W. HOWEVER...MOST OF THE ACTIVITY IN THE CARIBBEAN IS DUE TO UPPER LEVEL FEATURES. AN UPPER LOW IS BETWEEN THE BAHAMAS AND CUBA EXTENDING AN UPPER TROUGH OVER THE NW CARIBBEAN TO HONDURAS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM ALONG THE S COAST OF CUBA BETWEEN 78W-81W. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF THE CARIBBEAN PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED/NUMEROUS STRONG CONVECTION WITHIN 75 NM A RADIUS OF 16N74.5W WITH SCATTERED SHOWERS/THUNDERSTORMS WITHIN 120 NM OF LINE FROM PANAMA NEAR 9N78W TO ACROSS HAITI AND CUBA NEAR THE WINDWARD PASSAGE. THE ITCZ AXIS CROSSES PANAMA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS OVER PANAMA AND WITHIN 60 NM ALONG THE COAST BETWEEN 80W AND THE COSTA RICA BORDER. THE TROPICAL WAVE WILL EXIT THE CARIBBEAN OVER THE NEXT 24 HOURS AND A SECOND WAVE WILL MOVE INTO THE E CARIBBEAN ON SAT WHILE THE LOW IS EXPECTED TO DISSIPATE TO A SURFACE TROUGH BUT REMAIN WITHIN THE BASIN. ATLANTIC OCEAN... AT 14/0300 UTC..THE SURFACE TROUGH IN THE W ATLC EXTENDS FROM 30N72W TO 23N73W BEING SUPPORTED BY AN UPPER TROUGH THAT COVERS THE FAR W ATLC TO AN UPPER LOW SITUATED BETWEEN ANDROS ISLAND AND THE COAST OF CUBA. THE BROAD UPPER RIDGE FROM THE CARIBBEAN EXTENDS OVER THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC PROVIDING DIFFLUENCE ALOFT AND GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 150/200 NM OF A LINE FROM HISPANIOLA NEAR THE HAITI/DOMINICAN REPUBLIC BORDER TO BERMUDA. A BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A PAIR OF 1026 MB HIGHS WITH ONE CENTERED NEAR 29N28W AND A SECOND JUST TO THE NE NEAR 23N24W GIVING MOST THE REMAINDER OF THE AREA FAIR WEATHER TONIGHT. THE ONLY EXCEPTION IS SOME MID/HIGH CLOUDS ALONG THE WESTERN EDGE OF AN UPPER RIDGE THAT EXTENDS ALONG 14N FROM AFRICA TO 45W. $$ WALLACE