000 AXNT20 KNHC 170531 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT OCT 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0415 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 75W S OF 16N MOVING W NEAR 15 KT. WAVE COINCIDES WITH A BROAD AREA OF DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N13W 7N28W 8N43W 9N63W. THE ITCZ IS ACTIVE EARLY THIS MORNING WITH SCATTERED MODERATE/STRONG CONVECTION WITHIN 150 NM S OF THE AXIS BETWEEN 13W-20W...WITHIN 200 NM BOTH SIDES OF THE AXIS BETWEEN 20W-40W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 46W FROM 7N-11N. SCATTERED MODERATE/STRONG CONVECTION IS ALONG A LINE FROM 10N46W TO 12N37W. SIMILAR ACTIVITY IS WITHIN 150 NM BOTH SIDES OF THE AXIS BETWEEN 47W-51W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 0300 UTC...A COLD EXTENDS FROM THE WRN ATLC ACROSS FLORIDA ENTERING THE GULF OF MEXICO NEAR SARASOTA FLORIDA AT 27N83W CONTINUING ALONG 25N89W TO N OF TAMPICO MEXICO NEAR 24N98W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 100 NM OF THE FRONT. AN UPPER LEVEL TROUGH OVER THE ERN CONUS EXTENDS OVER THE NRN GULF N OF 25N SUPPORTING THE FRONT. AN UPPER LEVEL RIDGE EXTENDING FROM MEXICO COVERS THE SW GULF. SURFACE WINDS OF 20 TO 25 KT ARE BEHIND THE FRONT. EXPECT THE FRONT TO CONTINUE MOVING SE ACROSS THE GULF REACHING THE STRAITS OF FLORIDA BY LATE TONIGHT AND INTO SUN. HIGH PRESSURE WILL BUILD IN THE WAKE OF THE FRONT. THE CARIBBEAN SEA... MOST OF THE SHOWER ACTIVITY OVER THE CARIBBEAN HAS NOW DISSIPATED LEAVING THE BASIN FAIRLY CALM. A FEW ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS REMAIN IN THE CENTRAL CARIBBEAN FROM 14N-16N BETWEEN 70W-73W. RADAR IMAGERY FROM PUERTO RICO INDICATES ISOLATED SHOWERS S OF THE ISLAND FROM 17N-18N BETWEEN 64W-66W. THIS ACTIVITY MAY BE ENHANCED BY A SURFACE TROUGH ANALYZED IN THE ERN CARIBBEAN ALONG 63W/64W FROM 10N-16N. IN THE UPPER LEVELS...AN UPPER LEVEL INVERTED TROUGH EXTENDS FROM NICARAGUA NEAR 14N86W TO THE WINDWARD PASSAGE NEAR 20N74W CONTINUING E TO NEAR 18N64W. AN UPPER LEVEL RIDGE COVERS THE CENTRAL AND ERN CARIBBEAN CENTERED NEAR 12N67W. MODERATE TRADE WINDS ARE ACROSS MUCH OF THE BASIN. EXPECT THE TROPICAL WAVE ALONG 75W TO CONTINUE WWD ACROSS THE WRN CARIBBEAN. THE ATLANTIC OCEAN... AS OF 0300 UTC...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N77W EXTENDING SW TO NEAR DAYTONA FLORIDA CONTINUING INTO THE GULF OF MEXICO. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 200 NM AHEAD OF THE FRONT. AN UPPER LEVEL TROUGH OVER THE ERN CONUS EXTENDING OVER THE WRN ATLC SUPPORTS THE FRONTAL SYSTEM. THE REMAINDER OF THE WRN ATLC IS DOMINATED BY A BROAD SURFACE RIDGE SUPPORTED BY AN UPPER LEVEL HIGH CENTERED NEAR 25N60W. FARTHER E...ANOTHER COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N36W ALONG 27N40W 26N45W. ISOLATED SHOWERS ARE OUT AHEAD OF THE FRONT N OF 25N BETWEEN 31W-36W. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH ALONG 35W. A WEAK 1014 MB SURFACE LOW IS NEAR 26N30W. A SURFACE TROUGH EXTENDS AROUND THE LOW ALONG 28N32W 29N27W 26N25W 22N28W 18N40W. ISOLATED SHOWERS ARE FROM 22N-30N BETWEEN 23W-27W. THIS SYSTEM IS SUPPORTED BY ANOTHER UPPER LEVEL TROUGH EXTENDING FROM AN UPPER LOW NEAR 35N21W TO 14N34W. DIFFLUENCE ALOFT OVER THE TROPICAL ATLC IS SUPPORTING THE SHOWERS/THUNDERSTORMS ALONG THE ITCZ AXIS. $$ WALTON