000 AXNT20 KNHC 160000 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU OCT 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLC WITH AN AXIS EXTENDING FROM 16N24W TO 11N26W...MOVING W AT AROUND 5 TO 10 KT. SSMI TPW INDICATES THE WAVE IS EMBEDDED IN DEEP MOISTURE S OF 13N. A 700 MB TROUGH IS INDICATED IN GFS MODEL FIELDS IN THE VICINITY OF THE WAVE. ISOLATED MODERATE CONVECTION IS FROM 07N TO 14N BETWEEN 23W AND 28W. A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AN AXIS EXTENDING FROM 19N43W TO 10N46W...MOVING W AT AROUND 5 KT OVER THE PAST 24 HOURS. THIS WAVE IS EMBEDDED IN AN ENVIRONMENT OF MODERATE MOISTURE. TROUGHING IS INDICATED AT 700 MB BETWEEN 44W AND 49W. ISOLATED MODERATE CONVECTION IS FROM 10N TO 19N BETWEEN 38W AND 48W. A TROPICAL WAVE IS OVER THE W CARIBBEAN WITH AN AXIS EXTENDING FROM 10N81W TO A 1008 MB SURFACE LOW NEAR 11N82W. SUBTLE 700 MB TROUGHING IS CO-LOCATED WITH THE WAVE AXIS WITH HIGH MOISTURE IN THE ENVIRONMENT OF THE WAVE. AN UPPER LEVEL ANTICYCLONE SUPPORTS DIFFLUENCE ALOFT WHICH IS HELPING TO ENHANCE CONVECTION. SCATTERED MODERATE CONVECTION IS FROM 12N TO 18N BETWEEN 76W AND 84W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 15N20W TO 09N30W TO 07N36W...WHERE THE ITCZ BEGINS AND EXTENDS TO 12N44W...THEN RESUMES W OF A TROPICAL WAVE NEAR 11N46W TO 10N50W. OTHER THAN CONVECTION ASSOCIATED WITH THE TWO TROPICAL WAVES...ISOLATED MODERATE CONVECTION IS FROM 05N TO 09N BETWEEN 28W AND 37W...AND FROM 09N TO 18N BETWEEN 48W AND 50W. ...DISCUSSION... GULF OF MEXICO... MID TO UPPER LEVEL RIDGING IS BEGINNING TO BUILD N ACROSS THE SE GULF WHILE A SHORTWAVE PREVIOUSLY SUPPORTING A STATIONARY FRONT OVER THE GULF HAS MOVED E OF 70W. THE LOSS OF UPPER LEVEL SUPPORT AND WARM WATER TEMPERATURES ARE ALLOWING THE STATIONARY FRONT TO GRADUALLY DISSIPATE. THE BOUNDARY CURRENTLY EXTENDS FROM NEAR 27N82W TO 25N94W. AN UPPER TROUGH IS OVER THE SW GULF SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 22N87W TO 16N88W. THE COMBINATION OF UPPER LEVEL SUPPORT BY THE UPPER TROUGH AND UPPER LEVEL DIFFLUENCE WITH THE UPPER RIDGING OVER THE SE GULF...AND LOW LEVEL CONVERGENCE WITH THE SURFACE TROUGH SUPPORTS SCATTERED MODERATE CONVECTION S OF 23N BETWEEN 83W AND 91W. ISOLATED THUNDERSTORMS ARE OVER THE SW GULF S OF 15N ASSOCIATED WITH THE UPPER TROUGH. A DIURNAL SURFACE TROUGH IS OVER THE SW GULF FROM 23N98W TO 20N96W. ISOLATED THUNDERSTORMS ARE WITHIN 100 NM NE OF THE TROUGH AXIS. MODERATE TO FRESH E TO NE WINDS COVER THE EASTERN GULF. GENTLE TO MODERATE E TO NE WINDS COVER THE WESTERN GULF...EXCEPT WESTERLY W OF THE SW GULF SURFACE TROUGH. OVER THE NEXT 24 HOURS THE UPPER TROUGH WILL CONTINUE TO DRAW DEEP MOISTURE N OVER THE SOUTHERN GULF SUPPORTING CONVECTION S OF THE DISSIPATING STATIONARY FRONT. A WEAK SURFACE LOW MAY DEVELOP OVER THE SW GULF SUPPORTING CONVECTION. CARIBBEAN SEA... A BROAD UPPER LEVEL ANTICYCLONE IS CENTERED OVER CENTRAL AMERICA AND THE WESTERN CARIBBEAN. THE UPPER LEVEL DIFFLUENCE FROM THIS UPPER LEVEL FEATURE COMBINED WITH A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SUPPORTS CONVECTION OVER THE SW CARIBBEAN. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. A SURFACE TROUGH OVER THE EASTERN YUCATAN AND BELIZE...AND A BROAD AREA OF DEEP MOISTURE ACROSS MUCH OF THE NORTHERN CARIBBEAN SUPPORTS ISOLATED MODERATE CONVECTION FROM 18N TO 22N BETWEEN 78W AND 88W. DRIER AND MORE STABLE CONDITIONS COVER THE CARIBBEAN W OF 76W...INHIBITING CONVECTION ACROSS THAT PORTION OF THE BASIN. MODERATE TO FRESH TRADE WINDS COVER THE MAJORITY OF THE CARIBBEAN...WITH LIGHTER WINDS INDICATED BY SCATTEROMETER DATA S OF 12N OVER THE SW CARIBBEAN. OVER THE NEXT 24 HOURS CONVECTION IS EXPECTED TO CONTINUE OR INCREASE OVER THE NW CARIBBEAN. ...HISPANIOLA... ISOLATED MODERATE CONVECTION WITH SCATTERED THUNDERSTORMS ARE OCCURRING OVER THE S CENTRAL PORTION OF HISPANIOLA THIS EVENING IN THE PRESENCE OF MODERATE MOISTURE AND NORTHERLY FLOW ALOFT. THUNDERSTORMS SHOULD DISSIPATE LATER THIS EVENING WITH GENERALLY FAIR WEATHER EXPECTED OVERNIGHT THROUGH SAT MORNING. ADDITIONAL MAINLY ISOLATED THUNDERSTORMS CAN BE EXPECTED ONCE AGAIN SAT AFTERNOON AS THE CURRENT WEATHER PATTERN REMAINS IN PLACE. ATLANTIC OCEAN... A SHORTWAVE TROUGH ALONG 70W AND A LONGWAVE TROUGH OFF THE NE US COAST SUPPORTS A COLD FRONT THAT ENTERS OUR AREA OF DISCUSSION NEAR 31N70W AND EXTENDS TO 29N73W...WHERE IT TRANSITIONS TO A DISSIPATING STATIONARY FRONT TO 28N77W TO 28N80W. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 31N69W TO 25N77W. ISOLATED MODERATE CONVECTION IS FROM 22N TO 27N BETWEEN 69W AND 80W. ISOLATED THUNDERSTORMS ARE WITHIN 100 NM E OF THE PRE-FRONTAL TROUGH N OF 27N. FARTHER EAST...AN UPPER LOW IS CENTERED NEAR 21N55W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 175 NM OF THE UPPER LOW CENTER. A SURFACE TROUGH OVER THE TROPICAL CENTRAL ATLC EXTENDS FROM 15N57W TO 10N58W. ISOLATED MODERATE CONVECTION IS FROM 11N TO 16N BETWEEN 54W AND 57W. A SURFACE TROUGH IS OVER THE CENTRAL SUBTROPICAL ATLC EXTENDING FROM 29N47W TO 25N47W. NO SIGNIFICANT CONVECTION IS NOTED. A COLD FRONT IS OVER THE E ATLC...ENTERING OUR AREA OF DISCUSSION NEAR 32N18W TO 24N24W TO 23N38W...SUPPORTED BY A 1000 MB LOW CENTERED NEAR 32N25W. STRONG TO NEAR GALE FORCE WINDS ARE N OF 29N BETWEEN BETWEEN 30W AND THE COLD FRONT. NO SIGNIFICANT CONVECTION IS NOTED. OVER THE NEXT 24 HOURS CONVECTION WILL CONTINUE OVER THE BAHAMAS NEAR THE PRE-FRONTAL TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO