000 AXNT20 KNHC 021200 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED OCT 02 2013 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM JERRY IS CENTERED NEAR 28.1N 44.0W AT 02/0900 UTC OR ABOUT 1110 NM E OF BERMUDA AND ABOUT 1040 NM WSW OF THE AZORES MOVING W AT 1 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. ISOLATED MODERATE CONVECTION IS FROM 24N-30N BETWEEN 39W- 45W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. A SURFACE TROUGH IS ANALYZED ACROSS THE WESTERN CARIBBEAN SEA FROM COASTAL HONDURAS NEAR 16N84W INTO A 1009 MB LOW CENTERED NEAR 18N85W TO 24N84W. WATER VAPOR IMAGERY INDICATES THIS TROPICAL DISTURBANCE FALLS BENEATH AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 19N83W PRIMARILY ON THE WESTERN PERIPHERY IN THE AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE. LOW- LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE LOW AND TROUGH AXIS ALONG WITH A FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT IS GENERATING SCATTERED MODERATE AND ISOLATED STRONG CONVECTION OVER A LARGE AREA FROM 15N-24N BETWEEN 79W-86W. THIS DISTURBANCE IS EXPECTED TO MOVE NORTHWESTWARD TO NORTH-NORTHWESTWARD NEAR OR OVER THE NORTHEASTERN PORTION OF THE YUCATAN PENINSULA LATER TODAY...AND INTO THE SOUTHERN GULF OF MEXICO TONIGHT OR THURSDAY. SOME DEVELOPMENT IS POSSIBLE DURING THE NEXT COUPLE OF DAYS...AND THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. IT IS LIKELY THAT STRONG UPPER LEVEL WINDS WILL LIMIT DEVELOPMENT AS THE SYSTEM APPROACHES THE NORTHERN GULF OF MEXICO BY THE WEEKEND. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. LOCALLY HEAVY RAINS MAY AFFECT THE CAYMAN ISLANDS...PARTS OF CUBA...AND PARTS OF THE YUCATAN PENINSULA DURING THE NEXT DAY OR TWO. AN AIR FORCE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THE DISTURBANCE THIS AFTERNOON. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N34W TO 17N34W MOVING W AT 15-20 KT. THE WAVE REMAINS EMBEDDED WITHIN WEAK SURFACE TO 700 MB TROUGHING WITH A 700 MB RELATIVE VORTICITY MAXIMUM NOTED ALONG THE WAVE AXIS NEAR 14N. WHILE NO SIGNIFICANT DEEP CONVECTION IS NOTED AT THIS TIME...ISOLATED SHOWERS ARE OCCURRING FROM 09N-17N BETWEEN 28W-37W. TROPICAL WAVE EXTENDS FROM 13N44W TO 21N45W MOVING W-NW AT 10-15 KT. TOTAL PRECIPITABLE WATER IMAGERY INDICATES MOISTURE ASSOCIATED WITH THE WAVE CONTINUES TO STRETCH NORTHWARD INTO THE CYCLONIC CIRCULATION ASSOCIATED WITH TROPICAL STORM JERRY FROM A MAXIMUM NEAR 11N40W TO 20N43W. WITH WESTERLY WINDS ALOFT NOTED N OF 15N...CONVECTION WITH THIS WAVE REMAINS LIMITED AT THIS TIME WITH ONLY ISOLATED MODERATE CONVECTION OCCURRING IN THE VICINITY OF 18N44W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 12N28W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 12N39W TO 09N45W TO 06N56W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVES ACROSS THE CENTRAL TROPICAL ATLC... SCATTERED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 17W-25W. ISOLATED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 45W-52W. ...DISCUSSION... GULF OF MEXICO... SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES OVER THE GULF THIS MORNING BETWEEN A MIDDLE TO UPPER LEVEL LOW CENTERED INLAND OVER NORTHERN LOUISIANA NEAR 33N93W AND AN UPPER LEVEL RIDGE AXIS EXTENDING FROM THE WESTERN CARIBBEAN SEA NORTHWARD OVER PORTIONS OF THE EASTERN GULF TO 28N84W. WATER VAPOR IMAGERY INDICATES THAT MOST OF THIS FLOW ALOFT REMAINS RELATIVELY DRY...HOWEVER DUE TO PERSISTENT SOUTHEASTERLY RETURN FLOW ACROSS THE BASIN...LOW-LEVEL MOISTURE AND THE MARGINAL MID-LEVEL DYNAMICS ARE GENERATING ISOLATED SHOWERS NW OF A LINE FROM THE FLORIDA PANHANDLE NEAR 30N85W TO 23N98W. FARTHER SOUTHEAST...WITH A FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT ALREADY IN PLACE... MOISTURE AND CONVECTION ASSOCIATED WITH A SURFACE TROUGH ANALYZED ACROSS THE WESTERN CARIBBEAN SEA CONTINUES TO IMPACT PORTIONS OF THE SE GULF WATERS...FLORIDA STRAITS...AND FLORIDA KEYS THIS MORNING. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING PRIMARILY S OF 26N E OF 86W. LOOKING AHEAD...THE SURFACE TROUGH NOTED ACROSS THE WESTERN CARIBBEAN SEA AND THE ASSOCIATED LOW PRESSURE CENTER IS FORECAST TO MOVE NORTHWEST THEN NORTH OVER THE NEXT 24 TO 48 HOURS INTO THE SOUTH-CENTRAL AND SE GULF BY EARLY THURSDAY AND BEGIN IMPACTING THE NORTHERN GULF WATERS LATE THURSDAY INTO FRIDAY. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 19N83W AND IS PROVIDING FOR AN OVERALL DIFFLUENT ATMOSPHERE W OF 75W. AT THE SURFACE BENEATH THIS UPPER LEVEL FEATURE...A SURFACE TROUGH EXTENDS ALONG 85W WITH A 1009 MB LOW CENTERED ALONG THE AXIS NEAR 18N. LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED ALONG AND EAST OF THE SURFACE TROUGH GENERATING SCATTERED SHOWERS AND TSTMS FROM 16N-24N BETWEEN 78W- 87W. THE REMAINDER OF THE CENTRAL AND EASTERN CARIBBEAN FALLS UNDER THE INFLUENCE OF DRY AND OVERALL STABLE NORTHERLY FLOW ALOFT WITH ONLY WIDELY SCATTERED LOW-TOPPED SHOWERS OCCURRING WITHIN E-SE TRADES E OF 74W. THIS SHOWER ACTIVITY IS MOST CONCENTRATED THIS MORNING ACROSS THE SE CARIBBEAN AND SOUTHERN WINDWARD ISLANDS S OF 14N BETWEEN 59W-66W. HISPANIOLA... CURRENTLY NORTHERLY DRY AND STABLE UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY OVER HISPANIOLA THIS MORNING. THIS IS PROVIDING FOR AN OVERALL TRANQUIL MORNING PERIOD...HOWEVER LOW- LEVEL MOISTURE AND ISOLATED LOW-TOPPED SHOWERS ARE EXPECTED TO CONTINUE MOVING IN ACROSS THE ISLAND FROM THE EAST. E-SE TRADES ARE EXPECTED TO CONTINUE DURING THE NEXT 24 TO 36 HOURS WITH THIS LOW-LEVEL MOISTURE PROVIDING FOR A PASSING SHOWER HERE AND THERE THROUGH THE EARLY AFTERNOON HOURS. GIVEN THE PERSISTENCE OF LOW-LEVEL MOISTURE...PEAK DAYTIME HEATING...AND INSTABILITY...SCATTERED SHOWERS AND TSTMS CANNOT BE RULED OUT IN THE FORECAST FOR WEDNESDAY AFTERNOON AND EARLY EVENING. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM THE NORTHWEST NORTH ATLC NEAR 42N59W SW TO 32N68W TO A BASE NEAR 27N75W. WHILE PRIMARILY A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED NEAR 28N63W DOMINATES SURFACE CONDITIONS...THE MIDDLE TO UPPER LEVEL TROUGH IS GENERATING EXTENSIVE CLOUD COVER AND WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE SW NORTH ATLC FROM 23N-32N BETWEEN 60W-74W. TO THE SOUTHWEST OF THIS AREA...THE ADVECTION OF TROPICAL MOISTURE FROM THE WESTERN CARIBBEAN SEA CONTINUES TO IMPACT THE FLORIDA STRAITS AND BAHAMAS THIS MORNING WITH SCATTERED SHOWERS AND TSTMS OCCURRING FROM 21N-26N BETWEEN 75W-85W. OTHERWISE...ACROSS THE CENTRAL ATLC...TROPICAL STORM JERRY CONTINUES TO SPIN IN THE VICINITY OF 28N44W REMAINING EMBEDDED WITHIN THE SOUTHWESTERN PERIPHERY OF A BROAD MIDDLE TO UPPER LEVEL TROUGH NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN NORTH ATLC N OF 25N E OF 48W. AT THE SURFACE HOWEVER ACROSS THE EASTERN ATLC...A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED NEAR 26N34W IS PROVIDING FOR OVERALL FAIR CONDITIONS FROM 18N-32N E OF 38W. 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