000 AXNT20 KNHC 040524 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT JUL 04 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 0430 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 20N42W TO 5N46W MOVING W 25-30 KT. THIS WAVE COINCIDES WITH A HIGH AMPLITUDE DEEP LAYER MOISTURE MAXIMUM OBSERVED ON TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY INDICATES AN INVERTED-V CLOUD SIGNATURE IN THE VICINITY OF THE WAVE AXIS S OF 12N. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. A TROPICAL WAVE IS ALONG 65W S OF 20N MOVING W 25-30 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS OVER THE ERN CARIBBEAN FROM 11N-17N BETWEEN 65W-70W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER VENEZUELA FROM 5N-8N BETWEEN 63W-69W. THIS CONVECTION IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE SE OF AN UPPER LEVEL LOW IN THE ERN CARIBBEAN NEAR 14N71W. A TROPICAL WAVE IS ALONG 83W S OF 18N MOVING W NEAR 20 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION CONTINUES TO BE ENHANCED BY UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL RIDGE ACROSS THE SW CARIBBEAN AND CENTRAL AMERICA...AS WELL AS SURFACE CONVERGENCE FROM A PORTION OF THE E PACIFIC ITCZ. THIS CONVECTION IS S OF 11N W OF 81W INTO THE E PACIFIC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 14N13W 9N22W 8N34W 9N50W AND INTO S AMERICA TO NEAR 7N63W. SCATTERED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 17W-26W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT IS OVER THE FLORIDA PANHANDLE ALONG 31N81W 30N85W TO A 1015 MB SURFACE LOW OVER E LOUISIANA NEAR 31N91W. THIS FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH WITH AXIS EXTENDING DOWN THE ERN UNITED STATES COASTLINE INTO THE NE GULF NEAR 27N87W. A 1018 MB HIGH IS OVER THE CENTRAL GULF OF MEXICO NEAR 26N91W. A SURFACE TROUGH IS OVER THE YUCATAN PENINSULA EXTENDING FROM 22N89W TO 18N91W. ATMOSPHERIC INSTABILITY AND SURFACE CONVERGENCE NEAR THE TROUGH ARE SUPPORTING A LARGE CLUSTER OF NUMEROUS SHOWERS/THUNDERSTORMS OVER THE BAY OF CAMPECHE FROM 17N-22N BETWEEN 90W-95W. THE REMAINDER OF THE GULF IS EXPERIENCING GENERALLY FAIR WEATHER AND LIGHT WINDS DUE TO THE SURFACE HIGH WITH ENHANCED SELY SURFACE WINDS UP TO 15 KT IN THE NW PORTION OF THE GULF. EXPECT THE SURFACE RIDGE TO PERSIST OVER THE NEXT FEW DAYS. CARIBBEAN SEA... TWO TROPICAL WAVES ARE IMPACTING THE CARIBBEAN. THE TROPICAL WAVE ALONG 65W IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE ERN CARIBBEAN FROM 11N-17N BETWEEN 65W-70W. THIS SHOWER ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE SE OF AN UPPER LEVEL LOW NEAR 14N71W. THE OTHER TROPICAL WAVE ALONG 83W IN THE WRN CARIBBEAN IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS S OF 11N W OF 81W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO OCCURRING OVER CUBA...HAITI...AND THE ADJACENT WATERS N OF 19N BETWEEN 72W-86W. THIS ACTIVITY IS SUPPORTED BY ATMOSPHERIC INSTABILITY AND UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL LOW OVER THE NW CARIBBEAN NEAR 20N85W AND THE UPPER LEVEL RIDGE OVER THE WRN ATLC. ELY TRADE WINDS OF 20-30 KT COVER THE MAJORITY OF THE CARIBBEAN. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH EXTENDS DOWN THE ERN UNITED STATES COASTLINE EXTENDING ACROSS NE FLORIDA INTO THE NE GULF OF MEXICO. THIS UPPER TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N78W TO 31N79W WHERE IS TRANSITIONS TO A STATIONARY FRONT ACROSS THE FLORIDA PANHANDLE. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 100 NM AHEAD OF THE FRONTS N OF 29N. UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL TROUGH OVER THE ERN UNITED STATES AND AN UPPER LEVEL HIGH OVER THE WRN ATLC NEAR 30N58W ALONG WITH MOIST SWLY FLOW ALOFT ARE SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE NW BAHAMAS FROM 26N-29N BETWEEN 78W-80W...AS WELL AS N OF CUBA FROM 23N-25N BETWEEN 76W-80W. FARTHER TO THE E...THE UPPER LEVEL HIGH IS SUPPORTING A 1023 MB SURFACE HIGH CENTERED NEAR 27N59W BRINGING GENERALLY FAIR WEATHER N OF 20N BETWEEN 50W-74W. A 1014 MB SURFACE LOW IS AT THE EDGE OF THE DISCUSSION AREA NEAR 32N41W. A SURFACE TROUGH EXTENDS AHEAD OF THE LOW CENTER ALONG 30N39W TO 25N46W. A SHORTWAVE UPPER LEVEL TROUGH SUPPORTS THE SURFACE LOW AND SURFACE TROUGH. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS SUPPORTING ISOLATED SHOWERS WITHIN 100 NM EITHER SIDE OF THE TROUGH AXIS. THE ERN ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED NEAR 31N29W THAT IS PRODUCING AN AREA OF STRONG N-NE WINDS OF UP TO 30 KT ALONG THE NW AFRICA COAST FROM 28N-33N E OF 16W. $$ WALTON