000 AXNT20 KNHC 081707 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT AUG 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...TROPICAL WAVES... A TROPICAL WAVE HAS BEEN ADDED TO THE SURFACE ANALYSIS AT 08/1200 UTC OVER THE FAR E ATLC. THIS TROPICAL WAVE IS ALONG 15W/16W S OF 16N MOVING W 10-15 KT. RECENT VISIBLE SATELLITE IMAGERY INDICATES A WELL-DEFINED LOW/MID-LEVEL CYCLONIC CIRCULATION CENTER ASSOCIATED WITH THIS WAVE NEAR 11N16W. TIME-HEIGHT ANALYSES FROM BAMAKO IN MALI INDICATE THAT THE DIRECTION OF THE FLOW BELOW 550 MB SHIFTED FROM NORTHEASTERLY TO SOUTHEASTERLY BETWEEN 07/1200 UTC AND 07/1800 UTC...SUGGESTING WAVE PASSAGE AT BAMAKO DURING THIS TIME. SUNY ALBANY GFS ANALYSES DEPICT THE LOW-LEVEL VORTICITY MAXIMUM ASSOCIATED WITH THIS WAVE TRACKING WESTWARD ACROSS WEST CENTRAL AFRICA DURING THE LAST FEW DAYS. THE 5-DAY HOVMOLLER DIAGRAM FOR SATELLITE IMAGERY ALSO INDICATES AN AREA OF ENHANCED CLOUDINESS ASSOCIATED WITH THE WAVE TRACKING WESTWARD ACROSS WEST CENTRAL AFRICA DURING THE LAST FEW DAYS. A BAND OF NUMEROUS MODERATE/ISOLATED STRONG CONVECTION ASSOCIATED WITH THIS WAVE IS WITHIN 90 NM EITHER SIDE OF A LINE FROM 11N15W TO 10N17W TO 10N21W. A TROPICAL WAVE EXTENDS FROM 18N33W TO 15N27W TO 8N22W MOVING W NEAR 15 KT. THIS WAVE IS EMBEDDED WITHIN A WELL-DEFINED MAXIMUM IN DEEP LAYER MOISTURE THAT IS TILTED FROM NW TO SE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. RECENT VISIBLE SATELLITE IMAGERY DEPICTS CYCLONIC MOTION OF LOW LEVEL CLOUDS IN THE VICINITY OF THIS WAVE...PARTICULARLY FROM 10N-14N. SCATTERED MODERATE CONVECTION IS FROM 8N-10N BETWEEN 22W-24W. SCATTERED MODERATE CONVECTION IS ALSO FROM 13N-16N BETWEEN 23W-27W. A TROPICAL WAVE IS ALONG 42W/43W S OF 16N MOVING W 15-20 KT. THIS WAVE COINCIDES WITH AN INVERTED-V PATTERN IN THE COVERAGE OF LOW-LEVEL CLOUDS...ALONG WITH AN AREA OF ENHANCED LOW/MID-LEVEL CYCLONIC CIRCULATION NEAR 14N43W...BASED ON RECENT VISIBLE SATELLITE IMAGERY. DEEP LAYER DRY AIR AND ATMOSPHERIC STABILITY IN THE VICINITY OF AN UPPER LEVEL RIDGE ARE LIMITING DEEP CONVECTION NEAR THIS WAVE. HOWEVER...SCATTERED SHOWERS ARE OCCURRING FROM 11N-14N BETWEEN 38W-41W. A TROPICAL WAVE IS ALONG 58W S OF 15N MOVING W NEAR 15 KT. SATELLITE-DERIVED WINDS INDICATE CYCLONIC CURVATURE IN THE FLOW WITHIN THE 950-800 MB LAYER NEAR THIS WAVE. THE CIMSS WAVETRAK PRODUCT ALSO CONFIRMS THAT THIS WAVE COINCIDES WITH A MAXIMUM IN LOW-LEVEL CYCLONIC CIRCULATION. SCATTERED MODERATE CONVECTION IS FROM 10N-13N BETWEEN 55W-58W. A TROPICAL WAVE IS ALONG 75W S OF 20N MOVING W NEAR 20 KT. THIS WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. RECENT VISIBLE SATELLITE IMAGERY INDICATES CURVATURE IN LOW-LEVEL CLOUD BANDS ALONG THE WAVE AXIS FROM 13N-18N. MID/UPPER-LEVEL DRY AIR IS INHIBITING THE AREAL COVERAGE DEEP CONVECTION NEAR THIS WAVE. HOWEVER...SCATTERED MODERATE CONVECTION IS FROM 14N-16N BETWEEN 77W-80W AND FROM 9N-11N BETWEEN 79W-82W. A TROPICAL WAVE IS ALONG 94W/95W S OF 21N MOVING W NEAR 15 KT. THIS WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. THE CIMSS WAVETRAK PRODUCT INDICATES THAT THIS WAVE COINCIDES WITH A MAXIMUM IN LOW-LEVEL CYCLONIC CIRCULATION. STABLE ATMOSPHERIC CONDITIONS ASSOCIATED WITH AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE YUCATAN PENINSULA NEAR 20N88W ARE INHIBITING DEEP CONVECTION OVER N PORTIONS OF THIS WAVE. HOWEVER...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OCCURRING OVER SE MEXICO AND THE SW GULF OF MEXICO FROM 17N-20N BETWEEN 92W-95W. DEEP CONVECTION ASSOCIATED WITH THIS WAVE IS OCCURRING IN THE E PACIFIC REGION...WHICH IS DISCUSSED IN THE TROPICAL WEATHER DISCUSSION FOR THE E PACIFIC OCEAN UNDER AWIPS/WMO HEADERS MIATWDEP/AXPZ20. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 13N17W 11N23W 9N37W 13N52W 10N63W. A SURFACE TROUGH MOVING WESTWARD AT 5-10 KT IS EMBEDDED WITHIN THE ITCZ AND EXTENDS FROM 17N47W TO 10N52W WITH SCATTERED MODERATE CONVECTION FROM 10N-15N BETWEEN 48W-55W. ADDITIONALLY...SCATTERED MODERATE CONVECTION IS FROM 8N-10N BETWEEN 28W-30W. SCATTERED MODERATE CONVECTION IS ALSO FROM 9N-11N BETWEEN 61W-64W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH AXIS EXTENDS NORTHEASTWARD FROM CENTRAL MEXICO TO THE E COAST OF MEXICO NEAR 23N98W ACROSS THE NW GULF TO 28N93W TO AN UPPER LEVEL VORTICITY MAXIMUM OVER SE LOUISIANA NEAR 30N90W. ATMOSPHERIC INSTABILITY ASSOCIATED WITH THIS UPPER LEVEL TROUGH IS COMBINING WITH DEEP LAYER MOISTURE TO SUPPORT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF 27N W OF 90W. THE SOUTHERN PORTIONS OF THIS ACTIVITY ARE BEING ENHANCED BY LOW LEVEL CONVERGENCE OVER THE N PORTIONS OF THE TROPICAL WAVE ALONG 94W/95W S OF 21N. ADDITIONALLY...A SURFACE TROUGH OVER THE N GULF EXTENDS FROM THE FLORIDA PANHANDLE NEAR 27N85W TO 27N89W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 120 NM EITHER SIDE OF THIS SURFACE TROUGH...WHICH ARE BEING ENHANCED BY ATMOSPHERIC INSTABILITY NEAR THE AFOREMENTIONED UPPER LEVEL TROUGH. THE QUIKSCAT PASS AROUND 08/1145 UTC DEPICTS CYCLONIC CURVATURE IN THE LOW LEVEL FLOW NEAR THE SURFACE TROUGH. ACROSS THE SE GULF...STABLE ATMOSPHERIC CONDITIONS ASSOCIATED WITH AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE YUCATAN PENINSULA NEAR 20N88W ARE RESULTING IN GENERALLY FAIR WEATHER. CARIBBEAN SEA... UPPER LEVEL DIFFLUENCE IN NORTHEASTERLY FLOW ALOFT OVER THE NW CARIBBEAN IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 18N-20N BETWEEN 80W-83W. OVER THE CENTRAL CARIBBEAN...AN UPPER LEVEL TROUGH AXIS EXTENDS FROM 18N73W TO N COLOMBIA NEAR 10N75W. HOWEVER...DEEP LAYER DRY AIR EMBEDDED WITHIN THIS UPPER LEVEL TROUGH IS INHIBITING DEEP CONVECTION NEAR THE TROUGH. ACROSS THE E CARIBBEAN...DEEP LAYER DRY AIR IS RESULTING IN GENERALLY FAIR WEATHER. HOWEVER...SCATTERED SHOWERS AND THUNDERSTORMS ARE OCCURRING S OF 12N E OF 65W...INCLUDING NE PORTIONS OF VENEZUELA. THIS ACTIVITY IS BEING SUPPORTED BY LOW LEVEL CONVERGENCE NEAR THE ITCZ AXIS. THE SURFACE PRESSURE GRADIENT S OF A SURFACE RIDGE OVER THE CENTRAL AND E ATLC IS SUPPORTING FRESH TO STRONG TRADE WINDS ACROSS MUCH OF THE CENTRAL AND E CARIBBEAN. THE STRONGEST WINDS ARE NEAR THE COAST OF COLOMBIA...WHERE NE WINDS OF 25 TO 30 KT ARE OCCURRING. ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE TROUGH AXIS IS OVER THE SW NORTH ATLC AND EXTENDS FROM 29N78W TO 30N71W TO 32N65W TO NE OF THE DISCUSSION AREA. ATMOSPHERIC LIFT S OF THIS UPPER LEVEL SHORTWAVE TROUGH AXIS IS SUPPORTING A SURFACE TROUGH EXTENDING FROM 30N72W TO THE NW BAHAMAS NEAR 26N77W TO 25N78W. LOW LEVEL CONVERGENCE NEAR THE SURFACE TROUGH AND ATMOSPHERIC INSTABILITY ASSOCIATED WITH THE UPPER LEVEL SHORTWAVE TROUGH ARE SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 23N BETWEEN 71W-76W AND N OF 30N BETWEEN 65W-71W. TO THE E...AN UPPER LEVEL LOW IS CENTERED NEAR 24N68W...WITH UPPER LEVEL DIFFLUENCE IN SOUTHWESTERLY FLOW ALOFT TO THE E OF THE UPPER LEVEL LOW SUPPORTING SCATTERED SHOWERS FROM 21N-26N BETWEEN 62W-67W. ALSO...AN UPPER LEVEL LOW IS CENTERED NEAR 31N46W WITH AN ASSOCIATED SURFACE TROUGH EXTENDING FROM 31N49W TO 27N48W TO 24N46W. LOW LEVEL CONVERGENCE NEAR THIS SURFACE TROUGH AND ATMOSPHERIC INSTABILITY NEAR THIS UPPER LEVEL LOW ARE SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 27N BETWEEN 43W-52W. FARTHER TO THE E...A DEEP LAYER RIDGE IS PRESENT ACROSS THE CENTRAL AND E ATLC WITH AN ASSOCIATED 1028 MB SURFACE HIGH NEAR 36N37W. STABLE ATMOSPHERIC CONDITIONS IN THE VICINITY OF THIS DEEP LAYER RIDGE ARE RESULTING IN GENERALLY FAIR WEATHER ACROSS MUCH OF THE CENTRAL AND E ATLC. $$ COHEN