000 AXNT20 KNHC 111805 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN OCT 11 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 OVER THE EASTERN ATLC WITH AN AXIS THAT AS OF THE 1200 UTC ANALYSIS EXTENDED FROM 18N35W TO 10N42W. THIS POSITION WAS ESTIMATED BASED OFF A SUBTLE 700 MB TROUGH MODEL STREAMLINES. HOWEVER...ASCAT IMAGERY AS OF 1214 UTC HAS INDICATED THAT THE WAVE IS FARTHER WEST...EXTENDING FROM NEAR 18N39W TO 09N47W. THE FURTHER WEST POSITION WILL BE REFLECTED IN THE 1800 UTC MAP. THIS POSITION IS AGREED UPON BY LOOKING AT THE BROADER 700 MB TROUGHING THAT EXTENDS FROM 39W TO 51W IN THE ENVIRONMENT OF THE WAVE. DEEP MOISTURE IS S OF 14N ALONG THE WAVE AXIS WITH A DIFFLUENT ENVIRONMENT ALOFT. SCATTERED MODERATE CONVECTION IS WITHIN 250 NM OF EITHER SIDE OF A LINE FROM 18N37W TO 07N48W. A TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN WITH AN AXIS THAT EXTENDS FROM 19N80W TO 10N81W. DRY AIR IS INDICATED IN THE MID TO UPPER LEVELS N OF 15N IN THE WAVE ENVIRONMENT WITH HIGH MOISTURE S OF 15N. A 700 MB TROUGH IS INDICATED IN MODEL STREAMLINES BETWEEN 76W AND 84W. ISOLATED THUNDERSTORMS ARE WITHIN 50 NM OF THE WAVE AXIS N OF 15N. SCATTERED MODERATE CONVECTION IS S OF 15N BETWEEN 75W AND 84W. SOME OF THIS CONVECTION IS ALSO ASSOCIATED WITH A 1010 MB LOW NEAR COLOMBIA AND THE E PACIFIC MONSOON TROUGH. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 08N22W TO 08N32W. A SURFACE TROUGH EXTENDS N OF THE MONSOON TROUGH AXIS FROM 08N30W TO 13N30W. THE ITCZ AXIS EXTENDS FROM 12N44W TO 08N61W. OTHER THAN CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS FROM 05N TO 09N E OF 23W...AND FROM 07N TO 14N BETWEEN 24W AND 31W. ISOLATED MODERATE CONVECTION IS FROM 07N TO 13N BETWEEN 48W AND 61W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW CENTERED ALONG THE S CAROLINA COAST HAS A TROUGH AXIS THAT EXTENDS SW ACROSS FL TO THE CENTRAL GULF. THIS TROUGH SUPPORTS A COLD FRONT ACROSS CENTRAL FL NEAR 28N81W TO 27N85W TO 26N94W. A PRE-FRONTAL TROUGH...PREVIOUSLY ANALYZED AS A DECAYING COLD FRONT...EXTENDS FROM THE FL KEYS NEAR 25N81W TO 23N91W. SCATTERED SHOWERS ARE WITHIN 50 NM OF EITHER BOUNDARY. GENTLE NORTHERLY WINDS ARE BETWEEN THE PRE-FRONTAL TROUGH AND COLD FRONT. MODERATE TO FRESH NORTHERLY WINDS ARE N OF THE COLD FRONT. GENERALLY MODERATE N TO NE WINDS COVER THE WESTERN GULF AROUND HIGH PRESSURE CENTERED OVER NW MEXICO...EXCEPT A SMALL AREA OF GENTLE E TO SE WINDS WITHIN 100 NM OF THE TX COAST. A NON-CONVECTIVE DIURNAL SURFACE TROUGH IS OVER THE SW GULF FROM 22N91W TO 18N93W. OVER THE NEXT 24 HOURS THE PRE-FRONTAL TROUGH WILL EXIT THE GULF. THE COLD FRONT WILL MOVE SE AND WILL EXTEND FROM S FL TO THE YUCATAN CHANNEL BY MONDAY AFTERNOON. MODERATE TO FRESH N TO NE WINDS ARE EXPECTED OVER THE E GULF. HIGH PRESSURE WILL BECOME CENTERED OVER THE CENTRAL GULF WITH LIGHT WINDS OVER THE CENTRAL GULF AND MODERATE TO FRESH SOUTHERLY SURFACE WINDS OVER THE WESTERN GULF. CARIBBEAN SEA... A TROPICAL WAVE IS SUPPORTING CONVECTION OVER THE SW CARIBBEAN. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. A SHORTWAVE TROUGH IS OVER THE N CENTRAL CARIBBEAN WITH SW FLOW ALOFT ACROSS THE CARIBBEAN TO THE E OF THIS TROUGH. THE INTERACTION OF THIS TROUGH...SW FLOW...AND A MOIST AIRMASS SUPPORTS SCATTERED THUNDERSTORMS AND ISOLATED MODERATE CONVECTION WITHIN 125 NM OF A LINE FROM 17N77W TO 16N67W TO 12N61W. MODERATE TO FRESH TRADE WINDS COVER THE CENTRAL AND EASTERN CARIBBEAN. GENTLE WINDS COVER THE NW CARIBBEAN. OVER THE NEXT 24 HOURS CONVECTION WILL CONTINUE OVER THE SW CARIBBEAN AND CENTRAL CARIBBEAN. ...HISPANIOLA... AN UPPER TROUGH CENTERED OVER THE ISLANDS SUPPORTS ISOLATED THUNDERSTORMS. AN INCREASE IN MOISTURE FROM THE SE WILL SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING THROUGH TONIGHT. LINGERING MOISTURE WILL SUPPORT ADDITIONAL AFTERNOON AND EVENING THUNDERSTORMS ON MONDAY. ATLANTIC OCEAN... AN UPPER LEVEL LOW CENTERED NEAR THE S CAROLINA COAST SUPPORTS A COLD FRONT THAT ENTERS OUR AREA OF DISCUSSION NEAR 31N77W TO 28N81W. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 31N75W TO 25N81W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE BETWEEN THE FRONT AND TROUGH. SCATTERED MODERATE CONVECTION IS FROM 26N TO 31N BETWEEN THE SURFACE TROUGH AND 66W. SCATTERED THUNDERSTORMS ARE FROM 21N TO 26N BETWEEN 69W AND 77W. FARTHER EAST...A SURFACE TROUGH EXTENDS FROM 31N54W TO 27N57W. NO DEEP CONVECTION IS NOTED. A 1019 MB SURFACE HIGH IS CENTERED NEAR 27N51W. A 1020 MB SURFACE HIGH IS NEAR 29N35W. A SURFACE TROUGH EXTENDS FROM 21N11W TO 23N25W. NO DEEP CONVECTION IS NOTED. OVER THE NEXT 24 HOURS CONVECTION WILL CONTINUE E OF THE COLD FRONT AS IT MOVES E OVER THE SW N ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO