000 AXNT20 KNHC 281741 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 28 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 1630 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 28W/29W S OF 16N MOVING W NEAR 10 KT. VISIBLE SATELLITE IMAGERY AND RECENT SCATTEROMETER DATA INDICATE LOW-LEVEL CYCLONIC FLOW AROUND THE WAVE AXIS CONCENTRATED AROUND A 1013 MB LOW ALONG THE WAVE AXIS NEAR 13N. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS SHEARED TO THE E OF THE AXIS FROM 12N-17N BETWEEN 21W-28W. TROPICAL WAVE EXTENDS FROM 15N50W TO 7N53W MOVING W NEAR 15 KT. VISIBLE SATELLITE IMAGERY INDICATES BROAD LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS. THE WAVE ALSO COINCIDES WITH A BROAD AREA OF DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. DEEP CONVECTION IS CONFINED TO THE ITCZ. SCATTERED STRONG CONVECTION IS FROM 8N-12N BETWEEN 51W-56W. TROPICAL WAVE IS ALONG 64W S OF 17N MOVING W NEAR 10 KT. WAVE LIES WITHIN A BROAD AREA OF ENHANCED INCREASED MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS FROM 16N-18N BETWEEN 62W-66W AFFECTING THE WINDWARD ISLANDS AND PUERTO RICO. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 6N11W 6N20W 10N26W 9N41W 11N50W 10N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 10W-16W. SIMILAR ACTIVITY IS WITHIN 75 NM N OF THE AXIS BETWEEN 34W-50W. SIMILAR ACTIVITY IS ALSO FROM 9N-12N BETWEEN 56W-62W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 1500 UTC...THE FRONTAL SYSTEM OVER THE ERN GULF OF MEXICO HAS MAINLY DISSIPATED. A DYING COLD FRONT REMAINS ACROSS THE FLORIDA PANHANDLE FROM 31N83W ALONG 29N86W 26N88W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE FROM 24N-27N BETWEEN 84W-884W. A FORMING STATIONARY FRONT LINES THE LOUISIANA COAST FROM 29N89W ALONG 29N91W INTO TEXAS NEAR 30N95W. MOIST SWLY FLOW ALOFT AROUND THE BASE OF AN UPPER LEVEL TROUGH OVER THE SW UNITED STATES AND INTO NW MEXICO IS SUPPORTING CLOUDINESS AND POSSIBLE ISOLATED SHOWERS ACROSS MUCH OF THE NW PORTION OF THE BASIN. AN UPPER LEVEL RIDGE COVERS THE SE PORTION OF THE GULF EXTENDING FROM THE WRN ATLC TO THE YUCATAN PENINSULA. EXPECT THE FRONT IN THE NE GULF TO DISSIPATE LATER TODAY. A NEW COLD FRONT IS EXPECTED TO MOVE OFF THE TEXAS COAST BY SUN. THE CARIBBEAN SEA... MOST OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER THIS AFTERNOON. A LINE OF ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE NRN BASIN HAVE MOSTLY DISSIPATED. SHOWERS/THUNDERSTORMS REMAIN OVER THE ERN CARIBBEAN IN ASSOCIATION WITH THE TROPICAL WAVE ALONG 64W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO IN THE SW CARIBBEAN S OF 13N BETWEEN 71W-84W DUE TO SURFACE CONVERGENCE NEAR THE E PACIFIC ITCZ. THE NW CARIBBEAN IS COVERED BY DRY AIR AND SUBSIDENCE ALOFT AROUND AN UPPER LEVEL RIDGE EXTENDING FROM THE WRN ATLC ACROSS S FLORIDA TO THE YUCATAN PENINSULA. A BROAD UPPER LEVEL TROUGH COVERS THE REMAINDER OF THE BASIN CENTERED S OF HISPANIOLA NEAR 16N74W. WLY FLOW ALOFT AROUND THE BASE OF THIS UPPER LOW COVER THE AREA S OF 13N SHEARING THE SHOWER/THUNDERSTORM ACTIVITY IN THE SW PORTION OF THE BASIN. MODERATE TRADE WINDS ARE ACROSS MUCH OF THE CENTRAL CARIBBEAN. EXPECT THE TROPICAL WAVE ALONG 64W TO CONTINUE WWD. THE ATLANTIC OCEAN... MOIST SWLY AND DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH COVERING MUCH OF THE CONUS AND AN UPPER LEVEL RIDGE OVER THE WRN ATLC CENTERED NEAR 30N69W ARE SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS N OF 28N BETWEEN 72W-78W. THE UPPER LEVEL RIDGE IS ALSO SUPPORTING A BROAD SURFACE RIDGE ANCHORED BY A 1020 MB HIGH NEAR 30N65W. TO THE E...A COLD FRONT DIPS INTO THE AREA NEAR 32N33W ALONG 29N44W 32N57W. AN UPPER LEVEL TROUGH N OF 33N CENTERED NEAR 49N38W IS SUPPORTING THE FRONT. A WEAK SURFACE RIDGE ANCHORED BY A 1018 MB HIGH NEAR 23N24W COVERS THE REMAINDER OF THE BASIN. STRONG SWLY FLOW BETWEEN A SHORTWAVE UPPER TROUGH OVER THE ERN ATLC AND AN UPPER LEVEL RIDGE OVER WRN AFRICA IS SHEARING MOISTURE FROM THE ITCZ...AND THE TROPICAL WAVE ALONG 28W/29W...TOWARD THE NE SUPPORTING ISOLATED SHOWERS FROM 13N-19N E OF 22W. WLY FLOW ALOFT COVERS THE TROPICAL ATLC. $$ WALTON