000 AXNT20 KNHC 131152 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 13 2012 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 RAFAEL IS CENTERED NEAR 15.5N 63.9W AT 13/1200 UTC OR ABOUT 145 NM SSE OF SAINT CROIX MOVING NW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. WIDELY SCATTERED STRONG AND SCATTERED MODERATE CONVECTION ARE FROM 09N-23N BETWEEN 53W-65W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC. TROPICAL DEPRESSION PATTY IS CENTERED NEAR 25.5N 71.9W AT 13/0900 UTC OR ABOUT 245 NM ENE OF THE CENTRAL BAHAMAS REMAINING STATIONARY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SCATTERED MODERATE CONVECTION IS FROM 23N-28N BETWEEN 67W-72W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N31W TO 17N30W MOVING W AT 10 KT. BROAD AND WEAK CYCLONIC FLOW IS NOTED IN THE VICINITY OF THE WAVE AXIS AS IT COINCIDES WITH MAXIMUM MOISTURE VALUES IN RECENT TOTAL PRECIPITABLE WATER IMAGERY FROM 09N-15N BETWEEN 26W-32W. SCATTERED MODERATE CONVECTION IS FROM 10N-20N BETWEEN 24W-33W AND REMAINS LIKELY ENHANCED DUE TO UPPER LEVEL DIFFLUENT FLOW ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED NEAR 22N34W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 11N18W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N18W TO 09N25W TO 10N31W TO 09N44W TO 07N53W. SCATTERED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 17W-22W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N-10N BETWEEN 23W-30W...AND FROM 06N-12N BETWEEN 33W-46W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL RIDGE IS CENTERED OVER THE WESTERN GULF PROVIDING NW TO N FLOW ALOFT WITH WATER VAPOR IMAGERY INDICATING DRY AIR AND SUBSIDENCE DOMINATES. AT THE SURFACE...A RIDGE INFLUENCES THE ENTIRE GULF BASIN ANCHORED BY A 1033 MB HIGH CENTERED IN THE NE CONUS NEAR 42N77W. THE RIDGE AXIS EXTENDS S-SW ALONG THE EAST COAST OF THE U.S. WITH CLEAR SKIES NOTED ON SATELLITE IMAGERY THIS MORNING...HOWEVER...A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS PORTIONS OF THE FAR WESTERN GULF S OF 27N W OF 96W. THE SURFACE RIDGE IS FORECAST TO REMAIN ACROSS THE BASIN THROUGH THE WEEKEND WITH NE TO E WINDS EXPECTED E OF 90W AND E TO SE WINDS EXPECTED W OF 90W. CARIBBEAN SEA... AN UPPER LEVEL TROUGH AXIS EXTENDS SOUTHWESTWARD FROM OVER THE SW NORTH ATLC TO OVER THE NW CARIBBEAN ALONG 22N80W TO 14N85W. NW OF THE TROUGH AXIS...WATER VAPOR IMAGERY INDICATES VERY DRY NORTHERLY FLOW WHICH IS PROVIDING FOR OVERALL STABLE CONDITIONS ACROSS THE NW CARIBBEAN THIS MORNING. EAST OF THE UPPER LEVEL TROUGH AXIS...A NARROW CORRIDOR OF MIDDLE TO UPPER LEVEL MOISTURE IS NOTED ON WATER VAPOR IMAGERY EXTENDING FROM 20N75W TO 14N84W. MID-LEVEL LIFTING DYNAMICS AND LOW-LEVEL MOISTURE CONVERGENCE IS GENERATING ISOLATED SHOWERS AND TSTMS ACROSS EASTERN CUBA...THE ADJACENT COASTAL WATERS BETWEEN CUBA AND JAMAICA...AND AN AREA FROM 13N-18N BETWEEN 78W-84W. ACROSS THE SW CARIBBEAN...THE MONSOON TROUGH AXIS EXTENDS EASTWARD FROM THE EASTERN PACIFIC REGION ALONG 10N AND IS PROVIDING FOCUS FOR ISOLATED SHOWERS AND TSTMS FROM 09N-12N BETWEEN 75W-82W. FINALLY...TROPICAL STORM RAFAEL IS CENTERED OVER THE EASTERN CARIBBEAN AND LIES ON THE SE PERIPHERY OF AN UPPER LEVEL LOW CENTERED NEAR 21N68W. THIS LOW IS PROVIDING A WEAKNESS BETWEEN TWO MID-LEVEL RIDGES...ONE W OF 78W...THE OTHER E OF 60W...FOR RAFAEL TO TRACK ON AN OVERALL N-NW TRACK OVER THE NEXT SEVERAL DAYS. NUMEROUS SHOWERS AND SCATTERED STRONG TSTMS ARE OCCURRING FROM 09N-23N BETWEEN 53W-65W...INCLUDING THE LESSER ANTILLES... AND TRINIDAD AND TOBAGO. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH AXIS EXTENDS INTO THE DISCUSSION AREA NEAR 32N71W SW TO 22N80W AND INTO THE NW CARIBBEAN SEA. VERY DRY AIR ALOFT IS ASSOCIATED WITH THIS TROUGH WHICH IS RESULTING IN MOSTLY FAIR CONDITIONS FOR PORTIONS OF THE SW NORTH ATLC W OF 76W. A FEW ISOLATED LOW-TOPPED SHOWERS ARE HOWEVER OCCURRING WITHIN 60 NM EITHER SIDE OF A LINE FROM 30N76W TO 25N80W. TO THE EAST OF THE UPPER LEVEL TROUGH AXIS OVER THE REMAINDER OF THE SW NORTH ATLC...TROPICAL DEPRESSION PATTY CONTINUES TO ANCHOR A BROAD AREA OF SURFACE TROUGHING BETWEEN 64W-77W. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 20N-26N BETWEEN 74W-77W TO THE W-SW OF PATTY...WHILE CONVECTION ASSOCIATED WITH PATTY REMAINS MOSTLY IN THE NORTHEAST AND EAST QUADRANTS AND CONTINUES TO BE INFLUENCED BY STRONG SOUTHWESTERLY WIND SHEAR. SCATTERED SHOWERS AND TSTMS COVER THE AREA WITHIN 180 NM EITHER SIDE OF A STATIONARY FRONT FROM 26N71W TO BEYOND 32N64W. SE OF PATTY...CONVECTION FROM TROPICAL STORM RAFAEL CONTINUES TO IMPACT PORTIONS OF THE ATLC WATERS FROM 10N-24N BETWEEN 52W-65W. RAFAEL IS FORECAST TO MOVE INTO THE ATLC WATERS LATE SATURDAY AND CONTINUE ON A N-NW TRACK THROUGH LATE MONDAY. ELSEWHERE THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 35N38W. EMBEDDED WITHIN THE SURFACE RIDGE... AN UPPER LEVEL LOW IS NOTED ON WATER VAPOR IMAGERY CENTERED NEAR 22N34W AND IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 21N-24N BETWEEN 35W-37W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN