000 AXNT20 KNHC 031800 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON OCT 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... OPHELIA BECOMES A POST-TROPICAL CYCLONE AND THE LAST ADVISORY IS ISSUED AT 03/1500 UTC. AT THIS TIME...OPHELIA IS CENTERED NEAR 48.1N 52.0W OR ABOUT 95 NM...175 KM NNE OF CAPE RACE NEWFOUNDLAND MOVING E-NE OR 60 DEGREES AT 32 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. THE 1248 UTC ASCAT PASS HELPED TO RE-LOCATED THE CENTER OF PHILIPPE AND ALSO PROVIDED OBSERVATIONS OF MAXIMUM WINDS NEAR NEAR 55 KT. AT 03/1500 UTC...TROPICAL STORM PHILIPPE IS CENTERED NEAR 24.8N 55.8W MOVING W-SW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. NOW...THE CENTER OF PHILIPPE IS ONCE AGAIN NEAR THE DEEPEST CONVECTION. THE CYCLONE HAS BEEN ABLE TO MAINTAIN ITS INTENSITY...AND EVEN STRENGTHEN DESPITE THE HOSTILE CONDITIONS. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED ALONG 31W FROM 08N TO 17N MOVING W AT 10-15 KT. VISIBLE METEOSAT-9 SATELLITE IMAGERY INDICATES SOME CYCLONIC TURNING OF THE LOW-LEVEL CLOUDS WHERE THE WAVE MEETS THE ITCZ AXIS. IN ADDITION...THE 1112 UTC ASCAT PASS CONFIRMS THE PRESENCE OF THE WAVE WITH E TO SE WINDS E OF THE AXIS AND NE WINDS W OF THE WAVE AXIS. THIS SYSTEM COINCIDES WITH A SURGE OF MOISTURE OBSERVED IN THE TOTAL PRECIPITABLE WATER. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR DAKAR SENEGAL TO 14N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS CONTINUES FROM 14N20W TO 13N29W TO 07N45W TO 06N57W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS MORE CONCENTRATED NEAR THE INTERSECTION OF THE WAVE AND THE ITCZ AXIS AND COVERS THE AREA FROM 07N TO 12N BETWEEN 28W AND 33W. SCATTERED MODERATE CONVECTION IS ALSO NOTED S OF THE ITCZ TO 10N BETWEEN 22W AND 25W. SIMILAR CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE ITCZ AXIS FROM 34W TO 46W. ...DISCUSSION... GULF OF MEXICO... HIGH PRES CENTERED OVER ARKANSAS EXTENDS A RIDGE OVER MOST OF THE GULF REGION. ANOTHER 1021 MB HIGH PRES IS OVER MEXICO NEAR 22N98W. THE HIGH PRES N OF THE AREA IS FORECAST TO STRENGTHEN ON TUE WITH NE WINDS GRADUALLY INCREASING OVER THE SE PORTION OF THE GULF. THE PRES GRADIENT WILL FURTHER TIGHTEN RESULTING IN NE WINDS OF 20 TO 25 KT COVERING THE ENTIRE EASTERN HALF OF THE GULF BY THU NIGHT. VISIBLE SATELLITE IMAGERY SHOWS SCATTERED TO BROKEN STRATOCUMULUS CLOUDS ASSOCIATED WITH THE ADVECTION OF COOLER AIR OVER WARM WATERS. ALOFT...THE GULF IS UNDER THE INFLUENCE OF A DEEP LAYER TROUGH THAT EXTENDS FROM AN UPPER LEVEL LOW CENTERED OVER THE MID-ATLC AND NORTHEASTERN U.S. TO THE EASTERN PORTION OF THE BAY OF CAMPECHE. MODERATE TO STRONG SUBSIDENCE DOMINATES THE ENTIRE REGION WITH THE EXCEPTION OF THE EASTERN PORTION OF THE BAY OF CAMPECHE WHERE THE BASE OF THE AFOREMENTIONED TROUGH IS GENERATING A FEW SHOWERS AND TSTMS. CARIBBEAN SEA... A LARGE AREA OF SHOWERS AND TSTMS IS OVER THE NW CARIBBEAN VERY CLOSE TO THE CAYMAN ISLANDS WHERE TSTMS AND GUSTY WINDS HAVE BEEN REPORTED. THIS CONVECTIVE ACTIVITY IS ASSOCIATED WITH A SURFACE TROUGH THAT EXTENDS ALONG 83W FROM 15N TO THE ISLE OF YOUTH CUBA. THIS TROUGH IS EMBEDDED WITHIN AN AREA OF DEEP LAYERED MOISTURE AS DEPICTED ON THE TWD ANIMATION. COMPUTER MODEL HAS THIS MOISTURE DRIFTING WWD OVER THE NEXT COUPLE OF DAYS. A STATIONARY FRONT STRETCHES ACROSS WESTERN CUBA AND THE FAR NW CARIBBEAN ALONG 20N87W 17N88W. SOME SHOWERS ARE ALSO ALONG THE FRONTAL BOUNDARY. IT IS NORMAL FOR THIS TIME OF THE YEAR TO SEE THIS TYPE OF WEATHER PATTERN ACROSS THE NW CARIBBEAN. EASTERLY TRADES IN THE 15-20 KT RANGE DOMINATE THE E AND S CENTRAL CARIBBEAN...HIGHER NEAR THE COAST OF COLOMBIA WHERE FEW SHIP OBSERVATIONS AND AN EARLIER ASCAT PASS SHOWED WINDS OF 20-25 KT. ALOFT...AN UPPER LEVEL RIDGE AXIS EXTENDS FROM NORTHERN CENTRAL AMERICA TO NEAR JAMAICA. NORTH OF THE RIDGE AXIS...MOIST AND UNSTABLE SOUTHWESTERLY FLOW ALOFT DOMINATES. UPPER DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS HELPING TO INDUCE THE AREA OF NUMEROUS SHOWERS AND SCATTERED TSTMS OVER MUCH OF THE NW CARIBBEAN N OF 15N W OF 80W. SCATTERED SHOWERS AND TSTMS ARE NOTED OVER THE SW CARIBBEAN JUST N OF THE MONSOON TROUGH WHICH CROSSES PANAMA TO A 1010 MB LOW PRES NEAR 11N76W. ATLANTIC OCEAN... A STATIONARY FRONT ENTERS THE AREA NEAR 31N66W THE CONTINUES SW THROUGH WESTERN CUBA INTO THE NW CARIBBEAN. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ALONG THE FRONTAL BOUNDARY WHICH IS SUPPORTED BY THE ABOVE MENTIONED UPPER-LEVEL LOW/TROUGH. THE FRONT IS FORECAST TO MEANDER OVER THE SW N ATLC AND GRADUALLY DISSIPATE. FURTHER EAST...IS TROPICAL STORM PHILIPPE FORECAST TO MOVE ON A WEST-SOUTHWEST TRACK FOLLOWED BY A TURN TOWARD THE WEST-NORTHWEST WITH A DECREASE IN FORWARD SPEED AS HIGH PRES N OF THE TROPICAL CYCLONE WEAKENS. THIS HIGH PRES IS CURRENTLY SITUATED NEAR 39N46W AND HAS A RIDGE TO THE SW TO THE NE CARIBBEAN AND ANOTHER RIDGE TO THE SE TO NEAR 21N36W. PHILIPPE IS IN BETWEEN THESE RIDGES. THE REMNANTS OF THE FRONT ARE EXPECTED TO MERGE WITH TROPICAL CYCLONE PHILIPPE BY LATE WED. A LOW PRES SYSTEM IS OVER THE AZORES WITH A TROUGH EXTENDING SSW INTO THE FORECAST AREA ALONG 31N28W 24N31W. A STRONG UPPER-LEVEL LOW LOCATED NEAR 34N27W WITH A TROUGH EXTENDING SW TO THE WINDWARD ISLANDS SUPPORTS THE SURFACE LOW PRES/TROUGH. NEAR THE BASE OF THIS TROUGH THERE ARE SOME SHOWERS OVER THE WINDWARD ISLANDS AND REGIONAL WATERS. AN UPPER-LEVEL RIDGE IS ALONG THE WEST COAST OF AFRICA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR