000 AXNT20 KNHC 230551 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI SEP 23 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. ...SPECIAL FEATURES... TROPICAL STORM OPHELIA IS CENTERED NEAR 14.1N 49.9W AT 23/0300 UTC OR 710 NM E-SE OF THE LEEWARD ISLANDS MOVING W-NW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE CONVECTION IS FROM 10N-19N BETWEEN 44W-48W LOCATED MAINLY EAST OF THE LOW-LEVEL CIRCULATION. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 10N32W TO 17N30W MOVING W AT 10-15 KT. INFRARED SHORTWAVE SATELLITE IMAGERY AND LOW-LEVEL STREAMLINE ANALYSIS INDICATES BROAD CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS BETWEEN 30W-36W. LATE AFTERNOON WINDSAT AND ASCAT PASSES ALSO DEPICTED SURFACE CYCLONIC FLOW NEAR THE AXIS. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT ENHANCED DEEP LAYER MOISTURE ACCOMPANIES THE WAVE FROM 07N-23N BETWEEN 28W-36W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N16W ALONG 07N23W TO 08N27W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 07N-14N BETWEEN 16W-21W...AND SCATTERED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 19W-26W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LONGWAVE TROUGH WITH AXIS MOVING ACROSS THE CENTRAL CONUS IS IMPACTING THE WEATHER IN THE EASTERN GULF THIS EVENING. MIDDLE TO UPPER LEVEL DIFFLUENCE AROUND THE EASTERN PERIPHERY OF THE UPPER LEVEL TROUGHING IS SUPPORTING A LARGE AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS N OF 25N E OF 89W...INCLUDING PORTIONS OF THE CENTRAL FLORIDA PENINSULA. THE UPPER LEVEL TROUGH IS ALSO SUPPORTING A SURFACE TROUGH EXTENDING FROM THE MISSISSIPPI RIVER DELTA REGION SOUTHWARD TO 22N91W. THE REMAINDER OF THE GULF W OF THE SURFACE TROUGH IS UNDER MOSTLY CLEAR SKIES AND FAIR CONDITIONS DUE TO DRY AIR ALOFT. THE SURFACE TROUGH IS FORECAST TO REMAIN STATIONARY BEFORE BEING ABSORBED BY A COLD FRONT CURRENTLY PROGRESSING ACROSS NORTHERN LOUISIANA AND SE TEXAS THAT WILL MOVE INTO THE NW GULF BY FRIDAY MORNING. BEYOND FRIDAY AFTERNOON THE FRONT IS EXPECTED TO GRADUALLY WEAKEN OVER THE NORTH-CENTRAL AND NE GULF THROUGH LATE SATURDAY. CARIBBEAN SEA... RATHER BENIGN CONDITIONS IN THE MIDDLE AND UPPER LEVELS ACROSS THE WESTERN CARIBBEAN ARE LEADING TO MOSTLY FAIR CONDITIONS WITH TRADES REMAINING IN THE 10 TO 15 KT RANGE...AND STRONGER NEAR THE COAST OF COLOMBIA THIS EVENING. LINGERING AFTERNOON CONVECTION CONTINUES TO DIMINISH OVER EASTERN CUBA AND HISPANIOLA...WITH ISOLATED SHOWERS AND TSTMS N OF 14N BETWEEN 66W-74W...AND N OF 16N BETWEEN 76W-81W. A FEW ISOLATED SHOWERS ARE ALSO OCCURRING OVER THE SW CARIBBEAN S OF 16N BETWEEN 77W-83W DUE IN PART TO WEAK UPPER LEVEL TROUGHING WITH AXIS ALONG 84W PROGRESSING WESTWARD ACROSS NICARAGUA AND HONDURAS. FARTHER EAST ACROSS THE LESSER ANTILLES AND THE REMAINDER OF THE EASTERN CARIBBEAN E OF 66W...MOSTLY CLEAR SKIES AND FAIR CONDITIONS WILL REMAIN IN PLACE THROUGH THE OVERNIGHT HOURS... HOWEVER LOW-LEVEL MOISTURE CONVERGENCE ACROSS THE SE CARIBBEAN IS GENERATING ISOLATED SHOWERS S OF 12N BETWEEN 60W-65W... INCLUDING TOBAGO AND NORTHERN PORTIONS OF TRINIDAD. ATLANTIC OCEAN... A LARGE AREA OF LOW TO MIDDLE LEVEL MOISTURE RESIDES ON THE SOUTHERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SW NORTH ATLC WATERS NEAR 32N71W. WHILE NO SURFACE FEATURE IS ANALYZED EAST OF THE BAHAMAS...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN MARGINALLY CONVERGENT SE WINDS FROM 21N-28N BETWEEN 61W-76W. ON THE WESTERN PERIPHERY OF THE UPPER LEVEL RIDGE...MOISTURE STREAMING NORTHEASTWARD FROM THE EASTERN GULF OF MEXICO ACROSS THE FLORIDA PENINSULA IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS NW OF A LINE FROM 26N80W TO 32N76W. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC N OF 20N IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH CENTERED NEAR 37N59W AND A 1024 MB HIGH CENTERED NEAR 35N21W. A COLD FRONT AND ASSOCIATED LOW-LEVEL MOISTURE IS LOCATED NORTH OF THE DISCUSSION AREA BETWEEN THE TWO SURFACE HIGHS WITH THE COLD FRONT ANALYZED FROM THE AZORES NEAR 39N30W TO 32N41W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. OTHERWISE... TROPICAL STORM OPHELIA IS IMPACTING THE CENTRAL TROPICAL ATLC AND IS FORECAST TO TRACK W-NW OVER THE NEXT FEW DAYS TO NEAR 25N65W BY LATE TUESDAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN