000 AXNT20 KNHC 030553 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU OCT 03 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION JERRY IS CENTERED NEAR 29.7N 42.0W AT 03/0300 UTC OR ABOUT 895 NM WSW OF THE AZORES MOVING NE AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. ISOLATED MODERATE CONVECTION IS FROM 24N-31N BETWEEN 38W-45W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. A SURFACE TROUGH IS ANALYZED ACROSS THE SOUTHEAST GULF OF MEXICO AND THE WESTERN CARIBBEAN SEA FROM COASTAL HONDURAS NEAR 16N86W INTO A 1006 MB LOW CENTERED NEAR 20N86W TO 26N85W. WATER VAPOR IMAGERY INDICATES THIS TROPICAL DISTURBANCE FALLS BENEATH AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 21N82W 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 THE FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT IS GENERATING SCATTERED MODERATE AND ISOLATED STRONG CONVECTION FROM 19N-23N BETWEEN 84W-88W. THIS DISTURBANCE IS EXPECTED TO MOVE NORTH-NORTHWESTWARD THROUGH THE YUCATAN CHANNEL OVERNIGHT INTO THE CENTRAL GULF THURSDAY. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N42W TO 15N42W MOVING W AT 15 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 12N. ISOLATED MODERATE CONVECTION IS FROM 09N- 17N BETWEEN 39W-45W. TROPICAL WAVE EXTENDS FROM 10N52W TO 21N50W MOVING W-NW AT 10-15 KT. THE WAVE CONTINUES TO STRETCH NORTHWARD AS THE SURFACE TO 700 MB TROUGHING BROADENS BETWEEN 48W-58W. WITH SOUTHWESTERLY WIND SHEAR ALOFT TO THE NW OF THE WAVE AXIS...CONVECTION REMAINS LIMITED AT THIS TIME WITH ONLY ISOLATED MODERATE CONVECTION OCCURRING 07N-13N BETWEEN 48W-55W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 07N25W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N25W TO 07N41W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVES ACROSS THE CENTRAL TROPICAL ATLC...ISOLATED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 23W-33W. ...DISCUSSION... GULF OF MEXICO... SOUTH-SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES OVER THE GULF THIS EVENING BETWEEN A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDING FROM OVER LOUISIANA NEAR 31N93W TO A BASE NEAR 21N97W AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE NW CARIBBEAN SEA NEAR 21N82W. WATER VAPOR IMAGERY INDICATES THAT MOST OF THIS FLOW ALOFT REMAINS RELATIVELY DRY W OF 90W...LEAVING CONDITIONS ACROSS THE WESTERN GULF RELATIVELY QUIET THIS EVENING WITHIN E-SE SURFACE WINDS IN THE RANGE OF 10 TO 15 KT. ACROSS THE EASTERN GULF...MOISTURE INCREASES DUE TO A 1006 MB SURFACE LOW CENTERED ACROSS THE YUCATAN CHANNEL NEAR 20N86W AND THE ASSOCIATED TROUGHING EXTENDING NORTHWARD INTO THE SE GULF TO 26N85W. GIVEN A FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT ALREADY IN PLACE...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING PRIMARILY S OF 28N E OF 90W. LOOKING AHEAD...THE SURFACE LOW IS FORECAST TO MOVE NORTH-NORTHWEST DURING THE NEXT 24 TO 48 HOURS INTO THE CENTRAL AND SE GULF 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 21N82W AND IS PROVIDING FOR AN OVERALL DIFFLUENT ATMOSPHERE N OF 16N W OF 76W. AT THE SURFACE BENEATH THIS UPPER LEVEL FEATURE...A SURFACE TROUGH EXTENDS ALONG 86W WITH A 1006 MB LOW CENTERED ALONG THE AXIS NEAR 20N. LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED IN THE VICINITY OF THE LOW GENERATING SCATTERED SHOWERS AND STRONG TSTMS FROM 19N-23N BETWEEN 83W-87W. FARTHER SOUTH...WHILE THE UPPER LEVEL DIFFLUENT ENVIRONMENT REMAINS IN PLACE...LOW-LEVEL MOISTURE CONVERGENCE BECOMES SOMEWHAT WEAKER...HOWEVER INTERACTION WITH LAND AND DIFFERENTIAL HEATING CONTINUES TO GENERATE SCATTERED SHOWERS AND ISOLATED TSTMS FROM 08N-17N BETWEEN 82W-90W...INCLUDING INLAND PORTIONS OF COSTA RICA...NICARAGUA...HONDURAS...AND EL SALVADOR. THE REMAINDER OF THE CENTRAL AND EASTERN CARIBBEAN FALLS UNDER THE INFLUENCE OF DRY AND OVERALL STABLE NORTHEASTERLY FLOW ALOFT WITH ONLY WIDELY SCATTERED LOW-TOPPED SHOWERS OCCURRING WITHIN E- SE TRADES E OF 75W. HISPANIOLA... CURRENTLY NORTHERLY DRY AND STABLE UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY OVER HISPANIOLA THIS EVENING. THIS IS PROVIDING FOR AN OVERALL TRANQUIL OVERNIGHT 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 THURSDAY AFTERNOON AND EARLY EVENING. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM THE NORTHWEST NORTH ATLC NEAR 42N52W SW TO 32N62W INTO A MIDDLE TO UPPER LEVEL LOW NEAR 26N68W. WHILE PRIMARILY WEAK SURFACE RIDGING DOMINATES N OF 20N W OF 50W...THE MIDDLE TO UPPER LEVEL TROUGH IS GENERATING CLOUD COVER WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE SW NORTH ATLC WITHIN 180 NM EITHER SIDE OF A LINE FROM 22N70W TO 34N53W. OTHERWISE...A SHALLOW SURFACE TROUGH IS ANALYZED TO THE WEST OF THIS UPPER LEVEL FEATURE FROM 25N71W TO 32N78W. WITH A LACK OF UPPER LEVEL SUPPORT...ONLY A FEW ISOLATED SHOWERS ARE OCCURRING WITHIN 300 NM NE OF THE TROUGH AXIS. TO THE SOUTHWEST OF THIS AREA...THE ADVECTION OF TROPICAL MOISTURE FROM THE WESTERN CARIBBEAN SEA CONTINUES TO IMPACT THE FLORIDA STRAITS AND FLORIDA PENINSULA THIS EVENING WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING S OF 27N W OF 75W. OTHERWISE...ACROSS THE CENTRAL ATLC...TROPICAL DEPRESSION JERRY CONTINUES TO SPIN IN THE VICINITY OF 29N42W. SURROUNDING THE DEPRESSION IS RELATIVELY WEAK RIDGING ANCHORED BY A 1019 MB HIGH CENTERED NEAR 24N32W AND A 1019 MB HIGH CENTERED NEAR 35N37W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN