000 AXNT20 KNHC 040604 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...SPECIAL FEATURES... HURRICANE EARL WAS DOWNGRADED TO TROPICAL STORM AT 04/0300 UTC. TROPICAL STORM EARL IS CENTERED NEAR 40.6N 68.3W AT 04/0600 UTC OR ABOUT 90 NM E-SE OF NANTUCKET MASSACHUSETTS AND ABOUT 210 NM SW OF CAPE SABLE NOVA SCOTIA MOVING NE AT 26 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 960 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 KT. 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. HEAVY RAIN AND POSSIBLE ISOLATED THUNDERSTORMS COVER THE AREA N OF 35N BETWEEN 66W-73W INCLUDING THE PORTIONS OF NEW ENGLAND FROM RHODE ISLAND TO MAINE. TROPICAL DEPRESSION FIONA IS CENTERED NEAR 31.4N 64.9W AT 04/0300 UTC OR ABOUT 50 NM S OF BERMUDA MOVING N-NE AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1013 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. THIS IS THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER. FOR ADDITIONAL INFORMATION SEE LATEST HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE UNDER AWIPS/WMO HEADERS NFDHSFAT1/ FZNT01 KWBC. THERE IS NO DEEP CONVECTION REMAINING FOR FIONA ONLY A SMALL LOW LEVEL CLOUD SWIRL. THE REMNANT LOW OF GASTON IS CENTERED NEAR 15N43W ABOUT 1000 NM E OF THE LEEWARD ISLANDS MOVING W NEAR 9 KT. THE LOW LEVEL CENTER APPEARS TO B JUST UNDER THE SE PORTION OF THE DEEP CONVECTION. LOW IS EMBEDDED WITHIN AN AREA OF DEEP LAYERED MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED STRONG CONVECTION IS FROM 15N-18N BETWEEN 43W-46W. ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR GRADUAL DEVELOPMENT. IF THUNDERSTORMS CONTINUE TO FORM NEAR THE CENTER...THEN ADVISORIES COULD BE RE-INITIATED ON THIS SYSTEM LATER TODAY. THERE IS A HIGH CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS. A TROPICAL WAVE IS APPROACHING THE CAPE VERDE ISLANDS EXTENDING FROM 20N20W THROUGH A 1006 MB LOW NEAR 17N21W TO 10N24W. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY E OF A LINE FROM WESTERN SAHARA ACROSS THE CAPE VERDE ISLANDS TO NEAR 10N29W. SCATTERED/NUMEROUS STRONG CONVECTION IS TO THE E OF THE WAVE AXIS WITHIN 45/60 NM OF LINE FROM 19N18W TO 16N21W WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 200 NM W OF THE WAVE AXIS FROM 10N-15N. THE ACTIVITY ASSOCIATED WITH THIS ELONGATED AREA OF LOWER PRESSURE HAS CHANGED LITTLE TONIGHT. ENVIRONMENTAL CONDITIONS ARE MARGINALLY CONDUCIVE FOR SOME SLOW DEVELOPMENT DURING THE NEXT COUPLE OF DAYS. THERE IS A MEDIUM CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES NORTHWESTWARD NEAR 10 MPH. ...ITCZ... ITCZ AXIS EXTENDS FROM 9N21W 7N28W 11N35W THEN RESUMES NEAR 12N40W 10N51W 8N61W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-9N BETWEEN 26W-33W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 6N-10N BETWEEN 40W-46W. ...DISCUSSION... GULF OF MEXICO... AN ELONGATED CUT-OFF UPPER LOW IS OVER THE W GULF EXTENDING FROM VERMILION BAY LOUISIANA TO THE W BAY OF CAMPECHE NEAR 20N95W. A SURFACE TROUGH IS JUST TO THE E OF THE UPPER TROUGH EXTENDING FROM 26N88W ALONG 22N93W TO THE COAST OF S MEXICO NEAR 18N94W. AN UPPER RIDGE COVERS THE REMAINDER OF THE GULF WATERS ANCHORED IN THE FLORIDA STRAITS NEAR 25N80W AND EXTENDING AN AXIS NNW TO OVER S GEORGIA. DIFFLUENCE ALOFT COMBINED WITH SURFACE CONVERGING FLOW CONTINUES TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 29N87W TO 20N93W AND SCATTERED SHOWERS/THUNDERSTORMS ARE S OF 20N TO INLAND OVER S MEXICO E OF 95W TO THE YUCATAN PENINSULA. A DEEP LAYERED TROUGH COVERS MOST OF THE E HALF U.S. WITH THE EXCEPTION OF THE FAR SE SUPPORTING A COLD FRONT THAT EXTENDS ACROSS CENTRAL ALABAMA...S MISSISSIPPI...TO JUST INLAND ALONG THE COAST OF LOUISIANA AND TEXAS. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM LAKE CHARLES LOUISIANA ALONG 27N96W TO INLAND OVER MEXICO NEAR 24N98W WITH ISOLATED SHOWERS W OF SURFACE TROUGH. THE COLD FRONT IS EXPECTED TO ENTER THE GULF LATER THIS MORNING BRINGING DRIER AIR IN ITS WAKE...AS THE S GULF WILL CONTINUE TO EXPERIENCE SHOWERS/THUNDERSTORMS AS TROPICAL DEPRESSION ELEVEN-E CURRENTLY IN THE GULF OF TEHUANTEPEC MOVES NW TO OVER MEXICO. CARIBBEAN SEA... A BROAD UPPER RIDGE ANCHORED IN THE FLORIDA STRAITS NEAR 25N80W COVERS THE CARIBBEAN W OF 73W AND EXTENDS TO OVER THE GULF OF MEXICO PROVIDING MOSTLY E TO SE UPPER LEVEL FLOW. ABUNDANCE OF TROPICAL MOISTURE ALOFT REMAINS ACROSS THE W CARIBBEAN AND COMBINED WITH DIFFLUENCE ALOFT ARE GENERATING AN AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N TO OVER CUBA BETWEEN 77W-85W. A SURFACE TROUGH EXTENDS ACROSS THE CENTRAL CARIBBEAN FROM 16N76W TO PANAMA NEAR 9N79W. DENSE HIGH CLOUDS DOMINATE THE W CARIBBEAN FROM 70W-84W WITH UNDERLYING SCATTERED SHOWERS BENEATH. A BROAD UPPER TROUGH EXTENDING OVER THE CENTRAL ATLC COVERS THE E CARIBBEAN E OF 73W TO THE COAST OF VENEZUELA. THIS IS FUNNELING IN DRY STABLE AIR ALOFT N OF 13N E OF 70W LEAVING THE AREA REMARKABLY CLEAR TONIGHT INCLUDING THE LESSER ANTILLES AND PUERTO RICO. THE SURFACE RIDGE THAT COVERS THE W ATLC EXTENDS OVER THE NE CARIBBEAN N OF 17N E OF JAMAICA. ATLANTIC OCEAN... TROPICAL STORM EARL IS RAPIDLY MOVING NE BUT STILL REMAINS A CONCERN FOR NEW ENGLAND STATES AND THE CANADIAN MARITIMES. SEE SPECIAL FEATURES ABOVE. BROAD UPPER RIDGE THAT COVERS THE GULF OF MEXICO AND THE W CARIBBEAN IS ANCHORED IN THE FLORIDA STRAITS NEAR 25N80W COVERING THE W ATLC W OF 73W. AN UPPER TROUGH COVERS THE CENTRAL ATLC WITH THE AXIS EXTENDING FROM 30N49W THROUGH AN UPPER LOW NEAR 20N58W CONTINUING INTO THE E CARIBBEAN ACROSS THE N LEEWARD ISLANDS. THE UPPER LOW IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 45 NM OF LINE FROM 22N56W TO 19N59W. A BROAD E/W UPPER RIDGE COVERS THE REMAINDER OF ATLC S OF 30N E OF 50W ANCHORED NEAR 23N36W. A BROAD SURFACE RIDGE DOMINATES THE ATLC N OF 20N E OF 60W ANCHORED N OF THE DISCUSSION AREA AND FROM 18N-28N BETWEEN 60W-78W ANCHORED BY A 1019 MB HIGH NEAR 23N65W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW