000 AXNT20 KNHC 041800 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT SEP 04 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM EARL IS CENTERED NEAR 45.8N 63.2W AT 04/1800 UTC OR ABOUT 25 NM S OF CHARLOTTETOWN PRINCE EDWARD ISLAND MOVING NE AT 35 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 965 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 KT. NUMEROUS SHOWERS ARE FROM 44N-47N BETWEEN 61W-69W...INCLUDING FAR EASTERN MAINE...AND PORTIONS OF THE EASTERN CANADIAN MARITIMES. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/ WTNT32 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. THE REMNANT 1008 MB LOW OF GASTON IS CENTERED NEAR 16N46W MOVING WNW AT 10 KT. THE LOW-LEVEL CENTER REMAINS EXPOSED ON SATELLITE IMAGERY...HOWEVER CURVED BANDS OF CONVECTION SWIRL AROUND THE LOW WITH MOST OF THE CONVECTION SHEARED TO THE WEST. SCATTERED MODERATE CONVECTION IS LOCATED WITHIN 150 NM OF THE LOW CENTER IN THE WESTERN SEMICIRCLE. ...TROPICAL WAVES... TROPICAL WAVE IS OVER INTERIOR W AFRICA FROM 06N TO 14N ALONG 06W MOVING W AT 10 KT. A 1012 MB LOW IS CENTERED ALONG THE WAVE AXIS NEAR 09N06W. HOVMOLLER DIAGRAM EXAMINATION AND UPPER AIR TIME-SECTION ANALYSES INDICATE THIS WAVE PASSED NIAMEY NIGER AROUND 03/2100 UTC. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 10N-13N BETWEEN 07W-11W. TROPICAL WAVE EXTENDS FROM 18N19W TO A 1010 MB LOW CENTERED NEAR 14N22W THEN SSW TO 07N27W. THIS WAVE IS EMBEDDED WITHIN A BROAD AREA OF LOW-LEVEL CYCLONIC FLOW OVER THE EASTERN TROPICAL ATLC WITH SW MONSOONAL FLOW LOCATED S OF 10N THAT EXTENDS ALONG THE WAVE AXIS TO 06N30W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 240 NM W OF THE WAVE AXIS. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION MORE ASSOCIATED WITH THE SW MONSOONAL FLOW IS OCCURRING FROM 02N-09N BETWEEN 25W-36W. ...ITCZ... ITCZ AXIS EXTENDS ALONG 11N48W 08N59W 11N75W. ISOLATED MODERATE CONVECTION IS FROM 08N-11N BETWEEN 42W-49W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LONGWAVE TROUGH IS LOCATED OVER MUCH OF THE EASTERN CONUS THAT DIPS TO 29N. EMBEDDED WITHIN THIS TROUGHING...AN UPPER LEVEL SHORTWAVE TROUGH WITH AXIS ALONG 90W IS OVER THE CENTRAL GULF WATERS. THE LONGWAVE TROUGH SUPPORTS A COLD FRONT THAT EXTENDS ACROSS THE FLORIDA PANHANDLE AND ENTERS THE GULF NEAR 30N86W THEN WESTWARD TO 29N90W OVER SE LOUISIANA THEN TO THE TEXAS COAST NEAR 27N97W. THE SHORTWAVE TROUGH SUPPORTS A PAIR OF SURFACE TROUGHS. ONE IS ANALYZED FROM 28N86W TO 24N92W WITH SCATTERED SHOWERS AND TSTMS WITHIN 120 NM OF THE TROUGH AXIS. THE OTHER SURFACE TROUGH IS ANALYZED ALONG 28N93W 23N96W TO 19N95W WITH SCATTERED SHOWERS AND TSTMS WITHIN 120 NM OF THE MEXICO COAST S OF 25N AND OVER THE SW GULF S OF 24N W OF 92W. WHILE LOWER PRESSURE VALUES EXIST OVER THE SW GULF...GLOBAL MODELS ARE INDICATING CYCLOGENESIS IS POSSIBLE OVER THE NEXT 12-24 HOURS. ELSEWHERE...OVER THE REMAINDER OF THE GULF E OF 90W...AN UPPER LEVEL ANTICYCLONE IS ANCHORED OVER FLORIDA STRAITS NEAR 25N81W AND EXTENDS AN UPPER LEVEL RIDGE AXIS SW TO THE YUCATAN CHANNEL. WIDELY SCATTERED SHOWERS ARE OCCURRING FROM 23N-26N BETWEEN 78W-85W. CARIBBEAN SEA... NE UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY W OF 70W ON THE SOUTHERN PERIPHERY OF AN ANTICYCLONIC CIRCULATION CENTERED OVER THE FLORIDA STRAITS AND W ATLC NEAR 25N81W. THIS IS PROVIDING FOR AN UPPER LEVEL DIFFLUENT ENVIRONMENT ACROSS THE WESTERN CARIBBEAN WHICH IN TURN IS ENHANCING CONVECTION FOCUSED ALONG A SURFACE TROUGH ANALYZED FROM 10N75W TO 14N80W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 09N-15N BETWEEN 76W-83W. OTHER CONVECTIVE ACTIVITY IS LOCATED IN THE VICINITY OF JAMAICA WITH SCATTERED SHOWERS AND TSTMS FROM 15N-19N BETWEEN 75W-79W. E OF 70W...AN UPPER LEVEL LOW IS CENTERED NEAR 16N64W AND CONTINUES TO INTRODUCE MODERATELY DRY AIR OVER THE EASTERN CARIBBEAN AND LESSER ANTILLES. HOWEVER...OVER THE FAR SE CARIBBEAN THE UPPER LEVEL LOW IS ADVECTING MOISTURE NE WITH ISOLATED SHOWERS S OF 13N E OF 66W. ATLANTIC OCEAN... AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE STRAITS OF FLORIDA NEAR 25N81W AND EXTENDS AN UPPER LEVEL RIDGE AXIS NE TO 28N76W AND BEYOND 32N65W. THIS UPPER LEVEL RIDGE SUPPORTS A SURFACE RIDGE ALONG 25N THAT ENCOMPASSES THE W ATLC ANCHORED BY A 1018 MB HIGH CENTERED NEAR 26N67W. LOW- TO MID-LEVEL MOISTURE COUPLED WITH INSTABILITY W OF 65W IS GENERATING AREAS OF ISOLATED SHOWERS AND TSTMS N OF 20N W OF 65W. A SURFACE TROUGH...THE REMNANTS OF FIONA...IS ANALYZED FROM 30N63W 35N63W WITH SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 90 NM EITHER SIDE OF THE TROUGH AXIS. UPPER LEVEL TROUGHING COVERS THE CENTRAL ATLC WITH THE AXIS EXTENDING FROM AN UPPER LEVEL LOW CENTERED OVER THE NE CARIBBEAN NEAR 16N64W TO ANOTHER UPPER LEVEL LOW NEAR 33N53W. THE UPPER LOW IS GENERATING ISOLATED SHOWERS FROM 20N-24N BETWEEN 58W-62W. ELSEWHERE ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...A BROAD SURFACE RIDGE DOMINATES N OF 22N E OF 60W ANCHORED BY A 1023 MB HIGH CENTERED NEAR 32N35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN