000 AXNT20 KNHC 251715 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN OCT 25 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 1615 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 21N43W TO 7N49W MOVING W NEAR 20 KT. VISIBLE SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE BROAD LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS. THE WAVE ALSO LIES WITHIN A BROAD AREA OF AMPLIFIED MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS FROM 13N-18N BETWEEN 45W-48W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N12W 7N17W 8N24W 6N37W 9N53W 7N59W. SCATTERED STRONG CONVECTION IS ALONG THE AFRICA COAST FROM 6N-9N BETWEEN 9W-13W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM OF THE AXIS BETWEEN 20W-35W. SIMILAR ACTIVITY IS ALSO WITHIN 400 NM N OF THE AXIS BETWEEN 38W-45W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT REMAINS IN THE FAR SE GULF OF MEXICO ENTERING THE STRAITS OF FLORIDA NEAR 25N80W CONTINUING TO 22N87W. MOST OF THE ASSOCIATED SHOWER ACTIVITY HAS NOW DISSIPATED. HOWEVER...ISOLATED SHOWERS REMAIN POSSIBLE ALONG THE FRONT. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS THE WRN GULF FROM 20N-27N BETWEEN 92W-95W. THIS ACTIVITY IS ENHANCED BY DIFFLUENT FLOW AROUND THE BASE OF AN UPPER LEVEL TROUGH OVER MUCH OF THE CENTRAL CONUS AND THE GULF OF MEXICO WITH AXIS OVER CENTRAL MEXICO. A WEAK SURFACE RIDGE IS OVER THE NRN GULF EXTENDING UP THE ERN CONUS ANCHORED BY A 1020 MB HIGH OVER NRN ALABAMA. SURFACE WINDS OF 10 TO 15 KT ARE ACROSS THE BASIN MOVING ANTI-CYCLONICALLY AROUND THE WEAK SURFACE RIDGE. EXPECT THE STATIONARY FRONT TO DISSIPATE LATER TONIGHT. ANOTHER COLD FRONT IS EXPECTED TO MOVE OFF THE TEXAS COAST MON NIGHT. CARIBBEAN SEA... A WEAK SURFACE TROUGH IN THE FAR NW CARIBBEAN EXTENDS FROM 21N85W TO 16N97W. ISOLATED SHOWERS ARE POSSIBLE ALONG THE TROUGH AXIS. THE TROUGH LIES UNDER AN UPPER LEVEL RIDGE PROVIDING A DRY ATMOSPHERE ALOFT...INHIBITING THE SHOWER ACTIVITY NEAR THE TROUGH. A 1009 MB SURFACE LOW JUST OFF THE COAST OF COSTA RICA NEAR 11N82W SUPPORTS SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS FROM 10N-14N BETWEEN 80W-84W. ANOTHER SURFACE TROUGH EXTENDS S OF JAMAICA FROM 17N78W TO 12N78W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 75 NM OF THE TROUGH AXIS. THIS TROUGH IS SUPPORTED BY AN UPPER LEVEL LOW OVER CUBA NEAR 22N79W. ANOTHER UPPER LEVEL TROUGH COVERS THE ERN CARIBBEAN. DIFFLUENT FLOW ALOFT BETWEEN THE UPPER LOW AND THIS UPPER RIDGE OVER THE ERN PORTION OF THE BASIN SUPPORTS SCATTERED SHOWERS/THUNDERSTORMS N OF COLOMBIA AND VENEZUELA FROM 11N-15N BETWEEN 71W-75W...AND ISOLATED SHOWERS N OF 16N BETWEEN 72W-77W INCLUDING PORTIONS OF HISPANIOLA AND WRN CUBA. MODERATE TRADEWINDS ARE OVER MUCH OF THE BASIN WITH STRONGER WINDS IN THE NW CARIBBEAN AHEAD OF THE FRONT IN THE STRAITS OF FLORIDA AS WELL AS IN THE ERN CARIBBEAN. ATLANTIC OCEAN... A STATIONARY FRONT ENTERS THE DISCUSSION AREA NEAR 32N78W CONTINUING OFF THE E FLORIDA COAST ALONG 29N80W 25N80W AND INTO THE STRAITS OF FLORIDA. SCATTERED SHOWERS/THUNDERSTORMS ARE ALONG THE FRONT AXIS. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH COVERING MUCH OF THE CENTRAL/ERN CONUS AND GULF OF MEXICO. THE REMAINDER OF THE WRN ATLC IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1028 MB HIGH NEAR 38N55W. THE SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 30N65W. A SURFACE TROUGH EXTENDS E OF THE LESSER ANTILLES ALONG 14N54W TO 10N54W. ISOLATED SHOWERS ARE WITHIN 100 NM OF THE TROUGH AXIS. ACROSS THE ERN ATLC...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N32W TO 29N41W. ISOLATED SHOWERS ARE N OF 29N BETWEEN 30W-36W. A DYING STATIONARY FRONT IS AHEAD OF THE COLD FRONT EXTENDING FROM 32N27W TO 27N33W. ISOLATED SHOWERS ARE WITHIN 175 NM AHEAD OF THE FRONT. BOTH FRONTAL SYSTEMS ARE SUPPORTED BY AN UPPER LEVEL TROUGH EXTENDING FROM THE LESSER ANTILLES NEAR 16N62W NE TO NEAR 32N38W. A BROAD UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE ERN AND TROPICAL ATLC ENHANCING CONVECTION ALONG THE ITCZ. $$ WALTON