000 AXNT20 KNHC 132035 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE OCT 13 2015 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE CENTRAL TROPICAL ATLC ALONG 40W FROM 8N-17N MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. THE WAVE IS DEPICTED IN THE LATEST GFS 700 MB STREAMLINES AND 850 MB VORTICITY ANALYSIS. A SURGE OF MOISTURE IS ALSO ASSOCIATED WITH THE WAVE BASED ON THE TPW IMAGERY. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE E OF THE WAVE AXIS FROM 9N-13N BETWEEN 33W-37W AND FROM 10N-11N BETWEEN 37W-40W. A TROPICAL WAVE IS CURRENTLY MOVING ACROSS THE LESSER ANTILLES GENERATING SOME SHOWER ACTIVITY. AN AREA OF MODERATE CONVECTION IS NOTED OVER THE FAR SE CARIBBEAN AND NEAR THE SOUTHERN END OF THE WAVE AXIS COVERING FROM 11N-13N BETWEEN 61W-63W. MAINLY FRESH SE WINDS ARE SEEN BEHIND THE WAVE AXIS BASED ON A RECENT ASCAT PASS. THE WAVE SHOWS UP VERY WELL IN THE LATEST GFS 700 MB STREAMLINES AND COINCIDES WITH A BULGE OF MOISTURE IN THE TPW IMAGERY. THIS WAVE WILL MOVE ACROSS THE EASTERN CARIBBEAN THROUGH WED EVENING...AND IT IS EXPECTED TO WEAKEN AS IT MOVES ACROSS THE CENTRAL CARIBBEAN THU THROUGH FRI NIGHT. THE TROPICAL PREVIOUSLY LOCATED OVER THE NW CARIBBEAN AND CENTRAL AMERICA HAS FINALLY MOVED INTO THE EPAC REGION AND CURRENTLY IS AFFECTING SOUTHERN GUATEMALA WITH SOME CONVECTIVE ACTIVITY. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W ALONG 8N24W TO 10N29W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N-9N BETWEEN 15W- 21W...AND FROM 6N-11N BETWEEN 21W-29W. ...DISCUSSION... GULF OF MEXICO... A WEAKENING STATIONARY FRONT EXTENDS FROM THE FLORIDA KEYS TO THE NE YUCATAN PENINSULA GENERATING ISOLATED SHOWERS. A WEAK HIGH PRES OF 1014 MB IS BEHIND THE FRONTAL BOUNDARY NEAR 27N89W. THIS SYSTEM IS FORECAST TO DISSIPATE IN ABOUT 24 HOURS AS ANOTHER COLD FRONT ENTERS THE GULF REGION THIS EVENING. THE FRONT IS FORECAST TO MOVE SLOWLY S TO ALONG 26N BY THU MORNING WHILE GRADUALLY DISSIPATING. HIGH PRESSURE BUILDING OVER THE SOUTHEASTERN U.S. IN THE WAKE OF THE FRONT WILL BRING FRESH NE WINDS ACROSS E AND CENTRAL PORTIONS WED NIGHT AND THU THAT WILL EXPAND W THROUGH SAT. STRONG NW WINDS ARE LIKELY ALONG THE COAST OF VERACRUZ BY SAT AS A STRONGER HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE GULF REGION. ALOFT...AN UPPER-LEVEL TROUGH IS OVER THE EASTERN GULF AND EXTENDS FROM THE FLORIDA PANHANDLE TO THE YUCATAN PENINSULA INTO SE MEXICO AND THE GULF OF TEHUANTEPEC. THIS TROUGH SUPPORTS THE ABOVE MENTIONED WEAKENING FRONT. A LARGE UPPER RIDGE IS ANCHORED OFF THE SW COAST OF MEXICO AND COVERS MOST OF MEXICO AND TEXAS AS WELL AS THE WESTERN GULF. CARIBBEAN SEA... A TROPICAL WAVE IS MOVING INTO THE EASTERN CARIBBEAN. PLEASE SEE TROPICAL WAVES SECTION FOR DETAILS. A BROAD SURFACE TROUGH IS ANALYZED OVER THE WESTERN CARIBBEAN AND EXTENDS FROM 22N82W TO 18N82W TO 12N81W. SCATTERED MODERATE CONVECTION IS NOTED BEHIND THE TROUGH AXIS MAINLY FROM 16N-19N BETWEEN 79W-82W. MOISTURE ASSOCIATED WITH THIS TROUGH WILL SHIFT WESTWARD ACROSS CENTRAL AMERICA AND THE NW CARIBBEAN THROUGH WED NIGHT...THEN ACROSS THE YUCATAN PENINSULA ON THU...ENTERING THE EASTERN BAY OF CAMPECHE BY THU NIGHT. CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION CAN BE FOUND OVER THE SOUTH-CENTRAL CARIBBEAN AND JUST N OF THE COLOMBIAN/PANAMANIAM LOW PRES LOCATED NEAR 10.5N77W. A DIFFLUENT PATTERN ALOFT IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. THE MOST RECENT SCATTEROMETER PASS PROVIDED OBSERVATIONS OF FRESH TO LOCALLY STRONG WINDS ACROSS THE CENTRAL CARIBBEAN PARTICULARLY JUST N OF THE GUAJIRA PENINSULA. FRESH TO OCCASIONALLY STRONG TRADE WINDS ARE EXPECTED TO PULSE IN THE SOUTH-CENTRAL CARIBBEAN EACH NIGHT THROUGH FRI...WHILE GENTLE TO MODERATE TRADE WINDS PREVAIL ELSEWHERE THROUGH SAT. ...HISPANIOLA... DAYTIME HEATING...LOCAL SEA BREEZES AND MOUNTAIN UPSLOPE LIFTING WILL COMBINE WITH AVAILABLE MOISTURE TO PRODUCE ISOLATED SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS. MOISTURE WILL INCREASE ON THU WITH THE APPROACH OF THE NEXT TROPICAL WAVE GIVING THE ISLAND A BETTER CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. ATLANTIC OCEAN... AS OF 1500 UTC...A COLD FRONT EXTENDS FROM 31N72W TO THE NW BAHAMAS WHERE IT BECOMES STATIONARY TO THE FLORIDA KEYS. A NARROW BAND OF CLOUDS WITH ISOLATED SHOWERS IS ASSOCIATED WITH THE FRONT FORECAST TO DRIFT SE AND DISSIPATE THROUGH TONIGHT. FRESH TO STRONG SOUTHERLY WINDS ARE OBSERVED PER SCATTEROMETER DATA AHEAD OF THE FRONT DUE TO THE PRES GRADIENT BETWEEN THE FRONT AND A 1024 MB HIGH PRES LOCATED OVER THE CENTRAL ATLC NEAR 32N52W. THIS SYSTEM EXTENDS A RIDGE SW TO NEAR THE SE BAHAMAS. ANOTHER HIGH PRES CENTER OF 1021 MB SITUATED NEAR 27N31W DOMINATES THE REMAINDER THE ATLC. IN THE UPPER-LEVELS...A TROUGH OVER THE EASTERN UNITED STATES SUPPORTS THE AFOREMENTIONED FRONTAL BOUNDARY. AN ANTICYCLONE IS NEAR 30N57W AND A BROAD TROUGH ALOFT COVERS THE EASTERN ATLC. THE TROUGH EXTENDS FROM 31N35W TO A CUT-OFF LOW LOCATED NEAR 17N43W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR