000 AXNT20 KNHC 240551 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN MAY 24 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 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 48W S OF 10N MOVING W NEAR 18 KT. THIS WAVE IS ASSOCIATED WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. SATELLITE IMAGERY INDICATES THAT THE WAVE IS EMBEDDED WITHIN AN INVERTED-V CLOUD SIGNATURE...WITH CYCLONIC CIRCULATION IN THE MOTION OF THE LOW LEVEL CLOUDS IN THE VICINITY OF THE WAVE AXIS. ISOLATED MODERATE CONVECTION IS WITHIN 250 NM EITHER SIDE OF THE WAVE AXIS S OF 5N. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N12W 4N19W 1N28W CROSSING THE EQUATOR NEAR 32W EXTENDING JUST S OF THE EQUATOR TO THE COAST OF NE BRAZIL NEAR 1S47W. ISOLATED MODERATE CONVECTION IS S OF 6N BETWEEN 14W-21W. SCATTERED MODERATE CONVECTION IS ALSO S OF 3N BETWEEN 34W-51W. ...DISCUSSION... GULF OF MEXICO... A DEEP LAYER TROUGH IS PRESENT ACROSS THE GULF WITH AN AXIS EXTENDING FROM AN UPPER LOW OVER LOUISIANA NEAR 31N93W TO THE ERN STRAITS OF FLORIDA NEAR 24N80W. AN ASSOCIATED 1006 MB SURFACE LOW IS LOCATED INLAND ACROSS SRN MISSISSIPPI NEAR 32N89W...WITH A SURFACE TROUGH EXTENDING FROM THE LOW THROUGH MOBILE BAY TO 23N86W. LOW LEVEL CONVERGENCE ALONG THE SURFACE TROUGH...AS WELL AS UPPER LEVEL DIFFLUENCE NE OF THE UPPER TROUGH AXIS...ARE SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE BIG BEND REGION OF FLORIDA N OF 29N E OF 85W AND ALSO FROM 24N-27N BETWEEN 83W-85W IN THE E GULF. UPPER DIFFLUENCE NEAR THE BASE OF THE UPPER TROUGH IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE FLORIDA STRAITS E OF 83W. AS THE SURFACE LOW CONTINUES MOVING NW MAINLY LIGHTLY SOUTHERLY SURFACE FLOW WILL PREVAIL ACROSS THE ENTIRE GULF THROUGH TUES. ACROSS THE SW GULF...DEEP LAYER DRY AIR AND SUBSIDENCE ASSOCIATED WITH W-NW FLOW ALOFT IS SUPPORTING GENERALLY FAIR WEATHER CONDITIONS. CARIBBEAN SEA... SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS THE CARIBBEAN N OF 17N E OF 80W. THIS ACTIVITY IS BEING SUPPORTED BY UPPER LEVEL DIFFLUENCE IN MOIST WESTERLY FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH EXTENDING FROM THE GULF OF MEXICO TO OVER THE NW CARIBBEAN...AND AN UPPER LEVEL RIDGE ACROSS THE SW NORTH ATLC. THIS SYNOPTIC PATTERN HAS PERSISTED FOR THE PAST FEW DAYS AND IS RESULTING IN CONTINUED PRECIPITATION ACROSS CUBA... JAMAICA...HISPANIOLA...PUERTO RICO AND THE NEARBY COASTAL WATERS ACROSS THE NRN CARIBBEAN. THE UPPER TROUGH IS FORECAST TO DRIFT SLOWLY EWD AND BEGIN WEAKENING BY LATE MONDAY. ADDITIONAL SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS CENTRAL AMERICA AND THE SW CARIBBEAN WATERS SW OF A LINE FROM 15N83W TO 10N76W. THIS ACTIVITY IS BEING SUPPORTING BY UPPER LEVEL DIFFLUENCE ON THE EXTENSION OF AN UPPER LEVEL RIDGE FROM THE E PACIFIC REGION EWD TO 67W. MEANWHILE...THE SURFACE PRESSURE GRADIENT S OF A SURFACE RIDGE OVER THE W ATLC IS MAINTAINING ELY WINDS OF 20 TO 25 KT ACROSS PORTIONS OF THE ERN CARIBBEAN. ATLANTIC OCEAN... SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING SW OF A LINE FROM 32N81W NEAR THE SRN SOUTH CAROLINA COAST TO N OF THE LEEWARD ISLANDS NEAR 20N61W. THIS AREA INCLUDES THE BAHAMAS... TURKS AND CAICOS ISLANDS...GREATER ANTILLES AND ADJACENT NEARBY COASTAL WATERS ALONG THE ERN FLORIDA PENINSULA. THIS ACTIVITY IS BEING SUPPORTED BY UPPER LEVEL DIFFLUENCE IN MOIST SWLY FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE GULF OF MEXICO AND AN UPPER LEVEL RIDGE ACROSS THE SW NORTH ATLC. FARTHER TO THE E...AN UPPER LEVEL TROUGH IS PRESENT WITH AN AXIS EXTENDING FROM AN UPPER LEVEL LOW NEAR 32N47W TO 27N55W TO 26N65W. ATMOSPHERIC INSTABILITY NEAR THE UPPER LEVEL LOW AND TROUGH...AS WELL AS UPPER LEVEL DIFFLUENCE IN MOIST SOUTHWESTERLY FLOW ALOFT...ARE SUPPORTING SCATTERED MODERATE CONVECTION N OF 27N BETWEEN 37W-49W. ALSO...A SURFACE TROUGH EXTENDS FROM 31N47W INTO A 1021 MB SURFACE LOW NEAR 29N48W CONTINUING SW INTO A 1017 MB LOW NEAR 23N55W AND CONTINUING ALONG 20N61W TO N OF PUERTO RICO NEAR 19N65W. LOW LEVEL CONVERGENCE NEAR THE SURFACE LOWS AND TROUGH IS SUPPORTING SCATTERED SHOWERS WITHIN 120/150 NM OF THE TROUGH AXIS. ACROSS THE E ATLC...A SURFACE RIDGE IS PRESENT WHERE MAINLY ZONAL FLOW ALOFT IS OCCURRING AND FAIR WEATHER CONDITIONS PERSIST. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL RIDGE IS S OF 10N E OF 55W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER LEVEL RIDGE IS ENHANCING CONVECTION ASSOCIATED WITH THE ITCZ AND THE TROPICAL WAVE ALONG 48W. $$ HUFFMAN