000 AXNT20 KNHC 302355 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED SEP 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 30W S OF 12N MOVING W NEAR 15 KT. THE WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE AS NOTED IN TOTAL PRECIPITABLE WATER IMAGERY...AS WELL AS EXHIBITING LOW- TO MIDDLE-LEVEL CYCLONIC FLOW EVIDENT IN SATELLITE IMAGERY AND SATELLITE DERIVED WINDS. CIMSS WAVETRAK MODEL GUIDANCE ALSO INDICATES A BROAD AREA OF 850 MB RELATIVE VORTICITY OVER THE ERN ATLC FROM 5N-15N BETWEEN 25W-35W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 9N-12N BETWEEN 27W-34W. TROPICAL WAVE IS ALONG 48W S OF 18N MOVING W NEAR 15 KT. THE WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. ALSO...CIMSS WAVETRAK MODEL GUIDANCE INDICATES A CONCENTRATED AREA OF 850 MB RELATIVE VORTICITY CENTERED ALONG THE WAVE AXIS FROM 10N-17N. THIS LOW-LEVEL VORTICITY COUPLED WITH AN UPPER LEVEL DIFFLUENT PATTERN ALOFT IS GENERATING SCATTERED MODERATE CONVECTION FROM 10N-12N BETWEEN 48W-50W...AND FROM 15N-18N BETWEEN 43W-49W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N13W 10N30W 8N34W 11N48W 9N61W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION... SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE W AFRICA COAST FROM 7N-11N BETWEEN 10W-15W. SCATTERED MODERATE CONVECTION IS FROM 11N-13N BETWEEN 20W-23W...AND FROM 9N-11N BETWEEN 36W-39W. ...DISCUSSION... GULF OF MEXICO... AS OF 2100 UTC...AN COLD FRONT EXTENDS FROM S FLORIDA TO THE SOUTH CENTRAL GULF OF MEXICO ALONG 26N80W 23N90W. WIDELY SCATTERED MODERATE CONVECTION IS MOSTLY S OF THE FRONT OVER THE YUCATAN CHANNEL AND ALONG THE COAST OF W CUBA FROM 21N-24N BETWEEN 81W-86W. SCATTERED SHOWERS ARE OVER THE FLORIDA KEYS. OUTSIDE OF THE SE GULF...MOSTLY FAIR WEATHER PREVAILS. 5-10 KT NORTHERLY WINDS ARE OVER THE E GULF N OF THE FRONT. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE E GULF E OF 90W SUPPORTING THE COLD FRONT. A RIDGE IS OVER THE W GULF PRODUCING NW UPPER LEVEL FLOW. CONSIDERABLE UPPER LEVEL MOISTURE IS OVER THE SE GULF...CENTRAL AND SOUTHERN FLORIDA...AND CUBA. STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE GULF. EXPECT...THE COLD FRONT TO MOVE INTO THE W ATLANTIC OVER THE NEXT 24 HOURS WITH CONTINUED CONVECTION OVER THE STRAITS OF FLORIDA. ALSO EXPECT A NEW FRONTAL SYSTEM TO PRODUCE CONVECTION OVER E TEXAS AND LOUISIANA OVER THE NEXT 24 HOURS. CARIBBEAN SEA... FRESH TO STRONG TRADEWINDS ARE OVER THE CARIBBEAN SEA AND CENTRAL AMERICA. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER PANAMA FROM 6N-10N BETWEEN 77W-83W. WIDELY SCATTERED MODERATE CONVECTION IS OVER HISPANIOLA FROM 18N-20N BETWEEN 68W-72W. ISOLATED MODERATE CONVECTION IS INLAND OVER CENTRAL AMERICA N OF HONDURAS. SIMILAR CONVECTION IS OVER CUBA. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE WESTERN AND CENTRAL CARIBBEAN. DIFFLUENCE E OF THE TROUGH IS ENHANCING SHOWERS OVER THE LEEWARD ISLANDS. AN UPPER LEVEL RIDGE IS OVER THE E CARIBBEAN AND E OF 65W. STRONG SUBSIDENCE IS OVER THE CENTRAL AND NW CARIBBEAN. EXPECT...CONTINUED SHOWERS AND THUNDERSTORMS OVER CENTRAL AMERICA AND THE W CARIBBEAN OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A COLD FRONT IS OVER THE W ATLANTIC EXTENDING SW TO S FLORIDA ALONG 32N68W 26N80W. ISOLATED MODERATE CONVECTION IS OVER THE N BAHAMAS FROM 24N-27N BETWEEN 73W-79W. A 1017 MB HIGH IS OVER THE W ATLANTIC NEAR 24N61W. A SURFACE TROUGH...THE REMNANTS OF T.D. EIGHT IS OVER THE TROPICAL CENTRAL ATLANTIC ALONG 22N55W 16N56W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 20N-22N BETWEEN 50W-56W. A COLD FRONT IS OVER THE CENTRAL ATLANTIC ALONG 32N18W 28N24W 28N40W 29N47W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT. A 1019 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 22N39W. ANOTHER 1018 MB HIGH IS OVER THE E ATLANTIC NEAR 25N20W. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS N OF 20N W OF 70W. AN UPPER LEVEL RIDGE IS N OF 20N BETWEEN 60W-70W. AN UPPER LEVEL LOW IS OVER THE CENTRAL ATLANTIC NEAR 26N51W. UPPER LEVEL DIFFLUENCE N OF THE CENTER IS PRODUCING WIDELY SCATTERED MODERATE CONVECTION FROM 27N-30N BETWEEN 45W-50W. AN UPPER LEVEL TROUGH IS OVER THE E ATLANTIC N OF 20N AND E OF 50W. AN UPPER LEVEL HIGH IS OVER THE TROPICAL ATLANTIC NEAR 13N50W. ANOTHER UPPER LEVEL HIGH IS OVER W AFRICA NEAR 12N9W WITH RIDGING EXTENDING W OVER THE TROPICAL E ATLANTIC TO 25W. $$ FORMOSA