000 AXNT20 KNHC 241740 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUN 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 50W/51W S OF 11N MOVING W NEAR 15 KT. THIS WAVE IS ASSOCIATED WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. VISIBLE SATELLITE IMAGERY INDICATES THAT THIS WAVE COINCIDES WITH AN INVERTED-V PATTERN IN THE COVERAGE OF LOW LEVEL CLOUDS. THIS WAVE IS ALSO ASSOCIATED WITH LOW LEVEL CYCLONIC CIRCULATION BASED ON THE CIMSS WAVETRAK PRODUCT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-10N BETWEEN 47W-55W. A TROPICAL WAVE EXTENDS FROM 20N66W TO 14N68W TO 9N67W MOVING W NEAR 15 KT. THIS WAVE IS ASSOCIATED WITH A WELL-DEFINED MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. SURFACE OBSERVATIONS ACROSS THE E CARIBBEAN AND COMPUTER MODEL GUIDANCE INDICATE CYCLONIC CURVATURE IN THE LOW LEVEL FLOW IN THE VICINITY OF THIS WAVE. THIS WAVE IS BEING AMPLIFIED AS IT ENCOUNTERS SOUTHEASTERLY FLOW ACROSS THE E CARIBBEAN DRIVEN BY THE SURFACE TROUGH IN THE SW NORTH ATLC AND E GULF OF MEXICO. STABLE ATMOSPHERIC CONDITIONS BENEATH A BROAD UPPER LEVEL RIDGE OVER THE S AND E CARIBBEAN IS INHIBITING DEEP CONVECTION NEAR THIS WAVE. HOWEVER...SCATTERED SHOWERS ARE OCCURRING FROM 16N-19N BETWEEN 65W-68W INCLUDING PORTIONS OF PUERTO RICO. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N16W 7N28W 5N39W 6N48W AND INTO NE BRAZIL NEAR 6N58W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 17W-20W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 21W-30W. SCATTERED MODERATE CONVECTION IS FROM 4N-8N BETWEEN 34W-40W. SCATTERED MODERATE CONVECTION IS FROM 6N-8N BETWEEN 55W-59W. ...DISCUSSION... GULF OF MEXICO... LOW LEVEL CONVERGENCE ASSOCIATED WITH A 1009 MB SURFACE LOW OVER OVER THE FAR W GULF NEAR 24N98W IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE W GULF FROM 20N-26N W OF 96W INCLUDING PORTIONS OF E MEXICO. THIS ACTIVITY IS ALSO BEING SUPPORTED BY ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN UPPER LEVEL TROUGH OVER N MEXICO. ALSO...A SURFACE TROUGH ASSOCIATED WITH A DEEP LAYER TROUGH OVER THE W ATLC AND SE GULF IS AFFECTING PORTIONS OF THE E GULF. THIS SURFACE TROUGH EXTENDS FROM 30N88W TO 28N85W TO THE SW FLORIDA PENINSULA NEAR 26N82W. LOW LEVEL CONFLUENCE NEAR THE SURFACE TROUGH...ALONG WITH UPPER LEVEL DIFFLUENCE IN NORTHERLY FLOW ALOFT...ARE SUPPORTING NUMEROUS SHOWERS AND THUNDERSTORMS FROM 24N-29N BETWEEN 82W-88W. BETWEEN THE TWO AREAS OF SHOWERS AND THUNDERSTORMS...SUBSIDENCE AND DEEP LAYER DRY AIR ACROSS PORTIONS OF THE NW AND SOUTH CENTRAL GULF ARE RESULTING IN GENERALLY FAIR WEATHER. THIS SUBSIDENCE IS SUPPORTING A 1011 MB SURFACE HIGH OVER THE NW GULF NEAR 28N93W. CARIBBEAN SEA... A BROAD UPPER LEVEL RIDGE IS AFFECTING MUCH OF THE S AND E CARIBBEAN. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS RIDGE IS COMBINING WITH DEEP LAYER MOISTURE OVER THE SW CARIBBEAN TO RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS S OF 13N W OF 75W INCLUDING PORTIONS OF NICARAGUA AND N COLOMBIA. ACROSS THE NW CARIBBEAN...SUBSIDENCE IN NORTHEASTERLY FLOW ALOFT AND DEEP LAYER DRY AIR ARE RESULTING IN GENERALLY FAIR WEATHER. UPPER LEVEL DIFFLUENCE ACROSS THE NE CARIBBEAN IS RESULTING IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 16N E OF 66W INCLUDING PORTIONS OF THE LEEWARD ISLANDS. ATLANTIC OCEAN... A DEEP LAYER TROUGH OVER THE W ATLC AND SE GULF OF MEXICO IS ASSOCIATED WITH A SURFACE TROUGH EXTENDING FROM 31N69W TO 26N76W TO THE SE FLORIDA PENINSULA NEAR 26N80W. THE DEEP LAYER TROUGH IS ALSO ASSOCIATED WITH A STATIONARY FRONT EXTENDING FROM 31N65W TO 32N63W TO N OF THE DISCUSSION AREA. LOW LEVEL CONVERGENCE NEAR THE FRONT AND SURFACE TROUGH...AS WELL AS ATMOSPHERIC INSTABILITY...UPPER LEVEL DIFFLUENCE...AND ABUNDANT DEEP LAYER MOISTURE...ARE SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS N OF 23N BETWEEN 63W-71W AND FROM 22N-25N BETWEEN 71W-79W INCLUDING PORTIONS OF THE BAHAMAS. FARTHER TO THE E...GENERALLY FAIR WEATHER IS PRESENT ACROSS MUCH OF THE CENTRAL AND E ATLC...WHERE SUBSIDENCE IS OCCURRING NEAR A BROAD SURFACE RIDGE. THIS SURFACE RIDGE IS ASSOCIATED WITH A 1028 MB SURFACE HIGH NEAR 35N49W. HOWEVER...ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN UPPER LEVEL LOW NEAR 23N47W IS SUPPORTING SCATTERED SHOWERS FROM 22N-24N BETWEEN 46W-49W. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL RIDGE AXIS EXTENDS FROM 13N17W TO 10N24W...WITH ANOTHER UPPER LEVEL RIDGE S OF 10N BETWEEN 28W-34W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THESE UPPER LEVEL RIDGES IS SUPPORTING THE CONVECTION ASSOCIATED WITH THE ITCZ...AS WELL AS SCATTERED SHOWERS AND THUNDERSTORMS FROM 4N-7N BETWEEN 11W-20W. $$ COHEN