000 AXNT20 KNHC 091110 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN SEP 09 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 1045 UTC. ...SPECIAL FEATURES... HURRICANE MICHAEL IS CENTERED NEAR 33.8N 42.7W AT 09/0900 UTC OR ABOUT 925 MI...1485 KM WSW OF THE AZORES MOVING NW AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 975 MB. MAXIMUM SUSTAINED WIND SPEED IS 85 KT WITH GUSTS TO 105 KT. SCATTERED MODERATE CONVECTION IS FROM 32N-35N BETWEEN 41W-44W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. TROPICAL STORM LESLIE IS CENTERED NEAR 30.8N 62.5W AT 09/0900 UTC OR ABOUT 170 MI...275 KM SE OF BERMUDA MOVING N AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 988 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. A TROPICAL STORM WARNING IS IN EFFECT FOR BERMUDA. SWELLS GENERATED BY LESLIE WILL ALSO CONTINUE TO AFFECT BERMUDA. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 29N-34N BETWEEN 61W-65W. SEE LATEST NHC INTERMEDIATE PUBLIC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. A TROPICAL WAVE AND ASSOCIATED 1008 MB LOW IS ANALYZED A COUPLE OF HUNDRED MILES WEST OF THE CAPE VERDE ISLANDS FROM 20N25W TO THE LOW LEVEL CENTER NEAR 15N27W...MOVING W AT 10-15 KT. THIS SYSTEM COINCIDES WITH A SURGE OF DEEP LAYER MOISTURE NOTED ON TOTAL PRECIPITABLE WATER IMAGERY...AROUND THE OCEANIC MONSOONAL GYRE DESCRIBED BELOW. SCATTERED MODERATE CONVECTION IS FROM 13N-17N BETWEEN 26W-31W. ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR GRADUAL DEVELOPMENT OF THE WAVE. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA INTO MAURITANIA WHERE IT HAS BROKEN DUE TO THE CIRCULATION AROUND THE TROPICAL WAVE/LOW DISCUSSED IN THE SPECIAL FEATURES SECTION. THE MONSOON TROUGH CONTINUES FROM THE LOW CENTER AT 15N27W ALONG 11N40W TO 10N50W...WHERE IT TRANSITIONS INTO THE ITCZ CONTINUING W TO THE COAST OF TRINIDAD AND TOBAGO NEAR 11N61W. A SURFACE TROUGH IS WEST OF THE TROPICAL WAVE AND N OF THE MONSOON TROUGH ANALYZED FROM 19N38W TO 13N35W. CLUSTERS OF STRONG CONVECTION ARE FROM 5N-11N BETWEEN 20W-40W. SIMILAR CONVECTION IS MOVING OFF THE COAST OF LIBERIA...SIERRA LEONE AND GUINEA E OF 16W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 50 NM ON EITHER SIDE OF THE SURFACE TROUGH N OF 16N. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS UPPER LEVEL LONGWAVE TROUGH MOVES ACROSS THE FAR E AND SE CONUS NOTED ON WATER VAPOR IMAGERY. THIS UPPER FEATURE IS SUPPORTING A COLD FRONT EXTENDING INTO THE GULF OF MEXICO FROM THE FLORIDA PANHANDLE NEAR 30N84W ALONG 27N90W TO THE SRN TEXAS COAST NEAR 26N97W. MARINE OBSERVATIONS N OF THE FRONT SHOW NNE SURFACE WINDS OF UP TO 20 KT W OF 88W. A PRE-FRONTAL TROUGH IS ALSO ANALYZED FROM NRN FLORIDA NEAR 30N82W TO 27N85W. MOSAIC DOPPLER RADAR IMAGERY AND LIGHTNING DATA SHOW THE EXTENSION OF THE SHOWERS AND THUNDERSTORMS ALONG THE FRONTAL BOUNDARY WITHIN 70 NM ON EITHER SIDE OF IT. LOW LEVEL CONVERGENCE IN THE VICINITY OF THE PRE-FRONTAL TROUGH IS GENERATING STRONG CONVECTION MOVING INLAND OVER NRN FLORIDA...LEAVING ONLY SCATTERED MODERATE SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 30 NM ON EITHER SIDE OF ITS AXIS OVER THE TAMPA BAY AREA AND FAR ERN GULF WATERS. THIS TROUGH WILL EVENTUALLY MERGE WITH THE FRONT AS IT PUSHES SSE ACROSS THE NRN GULF DURING THE NEXT 24 HOURS. MODERATE TO HEAVY RAINFALL AND DANGEROUS LIGHTNING WILL CONTINUE ALONG THE FRONT DURING THE FORECAST PERIOD. THE REMAINDER OF THE BASIN IS UNDER MOSTLY FAIR WEATHER THIS MORNING. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS UNDER FAIR CONDITIONS THIS MORNING DUE TO DRY AIR ALOFT COVERING A GREAT PORTION OF THE BASIN. HOWEVER ...TOTAL PRECIPITABLE WATER IMAGERY SHOWS MODERATE TO HIGH AMOUNTS OF LOW LEVEL MOISTURE OVER THE FAR SW BASIN ADVECTING WESTWARD AGAINST THE COAST OF HONDURAS...NRN NICARAGUA AND COSTA RICA S OF 16N W OF 73W. WHILE MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY IS OCCURRING INLAND OVER THE MAJORITY OF CENTRAL AMERICA...WEAK SHOWERS ARE WIDELY SCATTERED ACROSS THE SW BASIN DUE TO CLOSE PROXIMITY TO THE ERN PACIFIC MONSOON TROUGH EXTENDING THROUGH INLAND PORTIONS OF COSTA RICA TO NRN COLOMBIA. TRADEWIND FLOW OF 10-15 KT IS ACROSS THE MAJORITY OF THE BASIN WITH SOME STRONGER WINDS GUSTING TO 25 KT NEAR THE COAST OF COLOMBIA. THE DRY SPELL ALOFT WILL CONTINUE ACROSS THE BASIN WITH FAIR CONDITIONS OVER THE MAJORITY OF THE BASIN DURING THE NEXT 24 HOURS. SHOWERS AND THUNDERSTORMS WILL LINGER OVER THE SW CORNER DURING THE FORECAST PERIOD. ATLANTIC OCEAN... WEATHER CONDITIONS ACROSS THE FAR WRN ATLC ARE ALREADY DETERIORATING THIS MORNING AS A COLD FRONT EMERGES OFF THE ERN CONUS SEABOARD WITH SCATTERED SHOWERS AND THUNDERSTORMS MOSTLY N OF THE AREA...AND WILL BEGIN TO IMPACT OUR DISCUSSION AREA OFF THE COAST OF FLORIDA AND GEORGIA LATER THIS AFTERNOON. THIS FRONTAL BOUNDARY IS SUPPORTED ALOFT BY AN UPPER LEVEL LONGWAVE TROUGH MOVING ACROSS THE FAR E AND SE CONUS NOTED ON WATER VAPOR IMAGERY. TROPICAL STORM LESLIE SPINS IN THE CENTRAL ATLC PRODUCING A LARGE AREA OF WINDS...SEAS...AND CONVECTION. HURRICANE MICHAEL IS WELL TO THE ENE OF LESLIE. SEE SPECIAL FEATURES SECTION FOR MORE DETAILS ON BOTH SYSTEMS. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS DOMINATED BY A BROAD UPPER LEVEL RIDGE COVERING THE ERN ATLC E OF 40W...AND A SURFACE 1024 MB HIGH NEAR 31N32W AND A 1022 MB HIGH NEAR 34N20W KEEPING FAIR WEATHER CONDITIONS ACROSS THE AREA. THE FAIR WEATHER ENVIRONMENT IS ENHANCED ALOFT BY SAHARAN DUST NOTED ON METEOSAT-9 SAL PRODUCT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA