000 AXNT20 KNHC 022336 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN SEP 02 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... POST-TROPICAL CYCLONE KIRK IS CENTERED NEAR 49.7N 32.6W AT 02/2100 UTC OR ABOUT 840 NM ENE OF CAPE RACE NEWFOUNDLAND...AND ABOUT 740 NM NNW OF THE AZORES MOVING NE AT 41 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. NO DEEP CONVECTION IS ASSOCIATED WITH THE SYSTEM. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. TROPICAL STORM LESLIE IS CENTERED NEAR 22.2N 61.4W AT 02/2100 UTC OR ABOUT 320 NM N OF THE LEEWARD ISLANDS MOVING NW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. NUMEROUS STRONG CONVECTION IS FROM 19N-23N BETWEEN 58W-63W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 17N-23N BETWEEN 57W-64W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 20N29W TO 13N32W MOVING W NEAR 12 KT. THE WAVE LIES ON THE WEST SIDE OF A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. AN EXTREMELY DRY AIR MASS TO THE N AND W OF THE WAVE IS LIMITING ANY DEEP CONVECTION NEAR THE AXIS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF MAURITANIA AT 18N16W CONTINUING TO SOUTH OF THE TROPICAL WAVE IN THE E ATLC AT 13N32W AND ENDING NEAR 9N47W. THE ITCZ BEGINS AT 9N47W AND CONTINUES TO 10N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-14N BETWEEN 17W-23W. SIMILAR ACTIVITY IS FROM 6N-8N BETWEEN 43W-52W. ...DISCUSSION... THE GULF OF MEXICO... SURFACE RIDGING CONTINUES TO DOMINATE THE GULF OF MEXICO EXTENDING FROM A 1020 MB HIGH CENTER SOUTH OF MISSISSIPPI AT 28N88W. THIS PATTERN IS PROVIDING MAINLY LIGHT E-SE FLOW ACROSS THE BASIN. THE SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE COVERING MUCH OF THE SOUTHERN CONUS AND PROVIDING DRY AIR ALOFT IN MAINLY NE FLOW. THIS COMBINATION OF DRY AIR ALOFT AND SURFACE RIDGING IS GENERATING MOSTLY FAIR CONDITIONS ACROSS THE BASIN. A FEW ISOLATED SHOWERS/THUNDERSTORMS DOT THE NORTHERN GULF COAST...FLORIDA...AND THE YUCATAN PENINSULA. SURFACE RIDGING IS EXPECTED TO REMAIN ACROSS THE BASIN FOR THE NEXT COUPLE OF DAYS. THE CARIBBEAN SEA... MOSTLY FAIR WEATHER COVERS THE CARIBBEAN TONIGHT DUE TO WIDESPREAD DRY AIR ALOFT MOVING OVER THE BASIN AROUND AN UPPER LEVEL TROUGH OVER THE WESTERN CARIBBEAN...AND AN UPPER LEVEL RIDGE OVER THE EASTERN CARIBBEAN. AFTERNOON CONVECTION OVER CUBA IS BEGINNING TO DIE DOWN WITH SOME SHOWERS/THUNDERSTORMS STILL REMAINING OVER THE ISLAND. SHOWERS/THUNDERSTORMS ARE ALSO ACROSS PORTIONS OF NICARAGUA AND THE MAJORITY OF COSTA RICA AND PANAMA ASSOCIATED WITH THE E PAC MONSOON TROUGH THAT EXTENDS THROUGH BOTH COUNTRIES TO A 1009 MB LOW OVER NORTHERN COLOMBIA. SOME POSSIBLE ISOLATED SHOWERS ARE ALSO OVER THE NORTHERN LEEWARD ISLANDS DUE TO T.S. LESLIE TO THE NORTH. TRADEWIND FLOW OF 10-15 KT IS ACROSS THE MAJORITY OF THE BASIN REACHING 20 KTS NEAR THE COAST OF COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... AN UPPER LEVEL LOW IS SPINNING OVER THE NW BAHAMAS NEAR 25N77W WITH AXIS EXTENDING INTO THE THE WESTERN CARIBBEAN. WHILE MOSTLY DRY AIR ACCOMPANIES THE UPPER LOW...A FEW ISOLATED SHOWERS/THUNDERSTORMS HAVE STILL POPPED UP FROM 24N-26N BETWEEN 75W-79W. TROPICAL STORM LESLIE IS PRODUCING A LARGE AREA OF STRONG SHOWERS/THUNDERSTORMS IN THE CENTRAL ATLC N OF THE LEEWARD ISLANDS. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. AN UPPER LEVEL RIDGE IS CENTERED JUST W OF THE STORM CENTER...AND SUPPORTS A WEAK 1021 MB SURFACE HIGH NEAR 27N50W. HOWEVER...AN UPPER LEVEL SHORTWAVE TROUGH MOVING THROUGH A LONGWAVE TROUGH TO THE NORTH IS HELPING SUPPORT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 23N-26N BETWEEN 50W-52W...AND FROM 25N-29N BETWEEN 52W-57W. AN UPPER LEVEL LOW TO THE E CENTERED NEAR 27N39W SUPPORTS A 1015 MB SURFACE LOW AT 26N40W. A SURFACE TROUGH EXTENDS THROUGH THE LOW CENTER FROM 32N40W TO 22N38W. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE TROUGH AXIS N OF 25N. THE REMAINDER OF THE E ATLC IS DOMINATED BY SURFACE RIDGING EXTENDING FROM A 1027 MB AZORES HIGH. THE HIGH IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED BOTH N OF THE AZORES NEAR 46N23W...AND SOUTH OF THE AZORES CENTERED NEAR 21N24W. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY ALONG WITH GOES-R ENHANCEMENT IMAGERY INDICATE A LARGE ARE OF DUST EXTENDS FROM THE COAST OF AFRICA AROUND THE WAVE AND MONSOON TROUGH IN THE E ATLC TO NEAR 50W. THIS DRY AIR MASS IS HELPING SUPPORT FAIR WEATHER IN THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON