000 AXNT20 KNHC 030558 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU NOV 03 2011 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. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 05N50W TO 13N45W MOVING W AT 10-15 KT. THE WAVE REMAINS EMBEDDED WITHIN DEEP LAYER TROPICAL MOISTURE ACROSS THE WESTERN TROPICAL ATLC WITH CYCLONIC TURNING OF THE LOW-LEVEL CLOUD FIELD IN THE VICINITY OF THE WAVE AXIS BETWEEN 45W-53W. ISOLATED MODERATE CONVECTION IS FROM 05N-13N BETWEEN 43W-51W...AND FROM 12N-15N BETWEEN 37W-48W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO 11N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N22W TO 05N38W. SCATTERED MODERATE CONVECTION IS FROM 01N-10N BETWEEN 24W-36W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER NORTHERN GUATEMALA NEAR 17N90W WHICH EXTENDS A RIDGE AXIS NORTHWARD ALONG 90W TO 27N THEN NE OVER THE SE CONUS. VERY DRY AIR ALOFT AND A SUBSIDENT ENVIRONMENT IS NOTED ACROSS MUCH OF THE GULF THIS EVENING AND THIS LARGELY SUPPORTS A SURFACE RIDGE WITH AXIS ACROSS THE BASIN FROM SOUTH CAROLINA SOUTHWESTWARD TO THE EAST-CENTRAL MEXICO COAST NEAR 22N98W. A WEAK SURFACE TROUGH IS EMBEDDED WITHIN THE SOUTHERN PERIPHERY OF THE RIDGE ANALYZED FROM 19N95W TO 22N96W WITH ISOLATED SHOWERS OCCURRING OVER PORTIONS OF THE WESTERN BAY OF CAMPECHE S OF 22N E OF 93W...AND FROM 20N-22N W OF 94W IN THE VICINITY OF THE SURFACE TROUGH. LOOKING AHEAD...AN UPPER LEVEL TROUGH IS PROGRESSING ACROSS THE SOUTHERN PLAINS THIS EVENING THAT SUPPORTS A COLD FRONT CURRENTLY MOVING ACROSS EASTERN TEXAS. THE FRONT IS FORECAST TO ENTER THE NW GULF WATERS WITHIN THE NEXT 6 TO 9 HOURS USHERING IN STRONG NORTHERLY WINDS WEST OF THE FRONT WHICH WILL SPREAD SE OVER THE WESTERN AND MIDDLE GULF WATERS THROUGH THE DAY ON THURSDAY. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION COVERS THE WESTERN CARIBBEAN W OF 77W AND MUCH OF CENTRAL AMERICA WHICH IS PROVIDING THE AREA WITH RELATIVELY DRY AND STABLE NW FLOW ALOFT THIS EVENING. MOSTLY FAIR CONDITIONS ARE NOTED ON SATELLITE IMAGERY WITH NORTHEAST WINDS TO 20 KT EXPECTED DURING THE OVERNIGHT HOURS. E OF 77W...UPPER LEVEL FLOW SHIFTS SOUTHWESTERLY ALOFT ADVECTING LOW TO MIDDLE LEVEL MOISTURE OVER THE EASTERN CARIBBEAN. LOW-LEVEL CONVERGENCE OF EASTERLY TRADES AND DIFFLUENCE ALOFT ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 13N-21N BETWEEN 60W-66W...AND ISOLATED SHOWERS ELSEWHERE BETWEEN 66W-73W. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH AXIS IS EVIDENT ON WATER VAPOR IMAGERY EXTENDING FROM 38N65W S-SW TO A BASE OVER EASTERN CUBA NEAR 20N77W. THIS UPPER LEVEL FEATURE SUPPORTS A COLD FRONT EXTENDING INTO THE DISCUSSION AREA NEAR 32N60W TO 27N65W THEN BECOMES A SHEAR LINE TO THE CENTRAL BAHAMAS THEN TO CENTRAL CUBA NEAR 22N80W. RECENT ASCAT PASSES AROUND 03/0124 UTC AND 03/0304 UTC INDICATED STRONGER NE WINDS NORTH OF THE SHEAR LINE TO 27N BETWEEN 70W-83W...INCLUDING THE FLORIDA STRAITS. ISOLATED SHOWERS ARE ALSO OCCURRING WITHIN 75 NM EITHER SIDE OF THE BOUNDARY. FARTHER SE OVER THE REMAINDER OF THE SW NORTH ATLC...A SURFACE TROUGH IS ANALYZED FROM 19N68W TO 28N62W WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 13N-21N BETWEEN 60W-66W...AND ISOLATED SHOWERS OCCURRING ELSEWHERE FROM 21N-32N BETWEEN 56W-64W. THE CENTRAL ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1026 MB HIGH CENTERED NEAR 32N41W. THE RIDGE AXIS EXTENDS SOUTHWARD ALONG 41W TO 17N. A SURFACE TROUGH IS EMBEDDED WITHIN THE SOUTHWESTERN PERIPHERY OF THE HIGH ANALYZED FROM 17N-24N ALONG 52W. AN UPPER LEVEL LOW IS CENTERED IN THE VICINITY OF THE SURFACE TROUGH NEAR 25N52W AND CONTINUES TO PROVIDE UPPER LEVEL DIFFLUENCE TO SUPPORT SCATTERED SHOWERS FROM 19N-28N BETWEEN 49W-54W. THE REMAINDER OF THE EASTERN ATLC SHOWS A WEAKENING COLD FRONT EXTENDING INTO THE DISCUSSION AREA ALONG 32N14W TO 27N25W TO 26N40W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN