000 AXNT20 KNHC 031204 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION JERRY IS CENTERED NEAR 30.2N 41.4W AT 03/0900 UTC OR ABOUT 855 NM WSW OF THE AZORES MOVING NE AT 8 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 28N-31N BETWEEN 36W-43W. 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 NEAR 26N86W INTO A 1006 MB LOW CENTERED NEAR 21N87W. WATER VAPOR IMAGERY INDICATES THIS TROPICAL DISTURBANCE FALLS BENEATH AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 21N84W PRIMARILY ON THE WESTERN PERIPHERY IN THE AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE. LOW-LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE LOW ALONG WITH THE FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT IS GENERATING SCATTERED MODERATE AND ISOLATED STRONG CONVECTION FROM 19N-24N BETWEEN 84W-87W. THIS DISTURBANCE IS EXPECTED TO MOVE NORTH-NORTHWESTWARD INTO THE CENTRAL GULF THURSDAY. DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT THE AREA OF LOW PRESSURE LOCATED OVER THE SOUTHEASTERN GULF OF MEXICO HAS BECOME A TROPICAL STORM AND IS PRODUCING WINDS OF UP TO 60 MPH IN THE EXTREME SOUTHEASTERN GULF OF MEXICO. A SPECIAL ADVISORY WILL BE ISSUED WITHIN THE NEXT HOUR...AND HURRICANE AND TROPICAL STORM WATCHES WILL BE ISSUED FOR PARTS OF THE NORTHERN GULF OF MEXICO COAST. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS AS IT MOVES NORTH-NORTHWESTWARD. HEAVY RAINS COULD AFFECT PORTIONS OF CUBA AND THE YUCATAN PENINSULA DURING THE NEXT DAY OR TWO. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS CURRENTLY INVESTIGATING THE SYSTEM. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 11N44W TO 19N42W 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 15N. ISOLATED MODERATE CONVECTION IS FROM 11N- 17N BETWEEN 39W-48W. TROPICAL WAVE EXTENDS FROM 13N54W TO 22N54W MOVING W-NW AT 10-15 KT. THE WAVE CONTINUES TO STRETCH NORTHWARD AS THE SURFACE TO 700 MB TROUGHING BROADENS BETWEEN 49W-60W. WITH SOUTHWESTERLY WIND SHEAR ALOFT TO THE NW OF THE WAVE AXIS...CONVECTION REMAINS LIMITED AT THIS TIME WITH ONLY ISOLATED MODERATE CONVECTION OCCURRING 08N-14N BETWEEN 49W-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 07N34W TO 11N42W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVES ACROSS THE CENTRAL TROPICAL ATLC... ISOLATED MODERATE CONVECTION IS FROM 06N-10N BETWEEN 30W-35W. ...DISCUSSION... GULF OF MEXICO... SOUTH-SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES OVER THE GULF THIS MORNING BETWEEN A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDING FROM OVER LOUISIANA NEAR 30N91W TO A BASE NEAR 20N98W AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE NW CARIBBEAN SEA NEAR 21N84W. 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 MORNING WITHIN LIGHT ANTICYCLONIC WINDS IN THE RANGE OF 5 TO 15 KT. ACROSS THE EASTERN GULF...MOISTURE INCREASES DUE TO A 1006 MB SURFACE LOW CENTERED NEAR THE NORTHEASTERN TIP OF THE YUCATAN PENINSULA NEAR 21N87W AND THE ASSOCIATED TROUGHING EXTENDING NORTHWARD INTO THE SE GULF TO 26N86W. GIVEN A FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT ALREADY IN PLACE...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING PRIMARILY S OF 28N E OF 90W...WITH PLENTY OF MIDDLE TO UPPER LEVEL CLOUDINESS SPREADING NORTHWARD ACROSS THE REMAINDER OF THE EASTERN GULF AND FLORIDA PENINSULA. LOOKING AHEAD...THE SURFACE LOW IS FORECAST TO MOVE NORTH-NORTHWEST DURING THE NEXT 24 TO 48 HOURS INTO THE CENTRAL GULF TODAY 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 21N84W AND IS PROVIDING FOR AN OVERALL DIFFLUENT ATMOSPHERE W OF 82W. AT THE SURFACE BENEATH THIS UPPER LEVEL FEATURE...A 1006 MB SURFACE LOW IS CENTERED 21N87W. LOW- LEVEL MOISTURE CONVERGENCE IS MAXIMIZED IN THE VICINITY OF THE LOW GENERATING WIDESPREAD SHOWERS AND SCATTERED STRONG TSTMS FROM 19N-24N BETWEEN 84W-88W...INCLUDING THE YUCATAN CHANNEL. 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 W OF A LINE FROM 18N85W TO 09N76W. MOST OF THIS ACTIVITY IS FOUND ACROSS CENTRAL AMERICA AND WITHIN CLOSE PROXIMITY TO THE MONSOON TROUGH AXIS ANALYZED ALONG 09N/10N. THE REMAINDER OF THE CENTRAL CARIBBEAN FALLS UNDER THE INFLUENCE OF DRY AND OVERALL STABLE NORTHEASTERLY FLOW ALOFT W OF AN UPPER LEVEL TROUGH AXIS EXTENDING FROM 18N66W TO 10N72W. ALONG AND TO THE EAST OF THIS UPPER LEVEL TROUGH AXIS...LOW-LEVEL MOISTURE CONVERGENCE AND MARGINAL DYNAMICS ARE GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS E OF 72W. 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...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 39N51W SW TO 32N60W INTO A MIDDLE TO UPPER LEVEL LOW NEAR 25N67W. WHILE PRIMARILY WEAK SURFACE RIDGING DOMINATES N OF 20N W OF 55W...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 32N54W TO 22N70W. OTHERWISE...A SHALLOW SURFACE TROUGH IS ANALYZED TO THE WEST OF THIS UPPER LEVEL FEATURE FROM 24N73W TO 27N72W TO 29N72W. WITH A LACK OF UPPER LEVEL SUPPORT...ONLY A FEW ISOLATED SHOWERS ARE OCCURRING WITHIN 210 NM E OF THE TROUGH AXIS. OTHERWISE...ACROSS THE CENTRAL ATLC...A COLD FRONT EXTENDS INTO THE DISCUSSION AREA NEAR 32N50W SW TO 27N55W WITH ISOLATED SHOWERS OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT. THE FRONT IS LOCATED WEST OF A WEAKNESS WITHIN TROPICAL RIDGING WHERE TROPICAL DEPRESSION JERRY CONTINUES TO SPIN IN THE VICINITY OF 30N42W. SURFACE TROUGHING EXTENDS SOUTHWEST OF THE SYSTEM WITH A SURFACE TROUGH ANALYZED FROM 21N49W TO 25N46W AND LIKELY ENERGY THAT FRACTURED OFF OF THE TROPICAL WAVE ALONG 54W. TO THE EAST OF THE DEPRESSION COVERING THE REMAINDER OF THE EASTERN ATLC...RELATIVELY WEAK RIDGING IS ANCHORED BY A PAIR OF 1018 MB HIGHS CENTERED NEAR 27NN33W AND 36N36W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN