000 AXNT20 KNHC 120539 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON SEP 12 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... TROPICAL STORM MARIA IS CENTERED NEAR 20.2N 65.9W AT 12/0300 UTC OR ABOUT 110 NM N OF SAN JUAN PUERTO RICO MOVING W-NW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. PLEASE SEE THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. MARIA CONTINUES TO BE UNDER WESTERLY SHEAR. SCATTERED/NUMEROUS STRONG CONVECTION IS E OF THE CENTER FROM 19N-21N BETWEEN 62W-65W WITH SCATTERED MODERATE/STRONG CONVECTION WITHIN 90 NM OF LINE FROM THE NE CARIBBEAN NEAR 15N64W ACROSS THE LEEWARD/VIRGIN ISLANDS TO 19N60W AND COVERING THE REMAINDER OF THE AREA FROM 19N-24N BETWEEN 60W-64W. MARIA IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 2-4 INCHES WITH ISOLATED MAXIMUM AMOUNTS OF 6 INCHES OVER THE THE VIRGIN ISLANDS...PUERTO RICO...AND PORTIONS OF THE NORTHERN LEEWARD ISLANDS DURING THE NEXT COUPLE OF DAYS. TROPICAL DEPRESSION NATE WAS DOWNGRADED TO A POST-TROPICAL LOW AT 12/0300 UTC. THE REMNANTS OF NATE IS CENTERED INLAND NEAR 20.5N 98.4W OR ABOUT 65 NM W-SW OF TUXPAN MEXICO MOVING W AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1012 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 30 KT. THIS IS THE LAST ADVISORY WRITTEN BY THE NATIONAL HURRICANE CENTER. ...TROPICAL WAVES... TROPICAL WAVE IS IN THE W/CENTRAL TROPICAL ATLC EXTENDING FROM 23N46W TO 12N50W MOVING NW NEAR 15 KT. WAVE IS EMBEDDED WITHIN DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS WELL DEFINED IN THE UPPER LEVEL SATELLITE WINDS AND IN THE CLOUD PATTERN ON THE SATELLITE IMAGERY. SCATTERED SHOWERS ARE WITHIN 180 NM EITHER SIDE OF THE WAVE AXIS MAINLY S OF 16N. TROPICAL WAVE IS IN THE W CARIBBEAN ALONG 84W/85W S OF 20N MOVING W 5-10 KT. WAVE IS EMBEDDED WITHIN DEEP LAYER MOISTURE THAT COVERS MOST OF THE CARIBBEAN AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE/ STRONG CONVECTION ARE FROM 14N-18N BETWEEN 81W-85W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA ENTERING THE E TROPICAL ATLC NEAR 19N16W ALONG 13N23W 8N37W. THE ITCZ CONTINUES FROM 8N37N 7N42W TO 8N47W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 120 NM OF LINE FROM 12N20W 7N25W TO 6N31W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-10N BETWEEN 40W-50W AND FROM 10N-12N BETWEEN 52-58W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH COVERS THE E CONUS INTO THE GULF N OF 25N GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 45 NM OF LINE FROM NE FLORIDA NEAR CEDAR KEY ALONG 26N90W TO LAGUNA MADRE MEXICO. AN INVERTED UPPER TROUGH IS OVER THE W BAY OF CAMPECHE EXTENDING FROM VERACRUZ TO NEAR 22N92W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 20N-23N W OF 95W TO THE COAST OF MEXICO. A BROAD UPPER RIDGE ANCHORED IN THE W CARIBBEAN EXTENDS OVER THE REMAINDER OF THE GULF. DIFFLUENT FLOW BETWEEN THE UPPER RIDGE IN THE CARIBBEAN AND THE UPPER TROUGH OVER THE W BAY OF CAMPECHE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 22N BETWEEN 84W-94W TO INLAND OVER MEXICO AND THE YUCATAN PENINSULA AND S OF 26N BETWEEN 80W-84W TO OVER THE FLORIDA KEYS AND ALONG THE N COAST OF CUBA. A WEAK SURFACE RIDGE COVERS THE N GULF ANCHORED BY A 1020 MB HIGH ALONG THE COAST OF LOUISIANA NEAR 29N91W LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES TONIGHT. SURFACE RIDGE WILL REMAIN NEARLY STATIONARY OVER THE N GULF THROUGH FRI. CARIBBEAN SEA... TROPICAL STORM MARIA IS PRODUCING THE SHOWERS/THUNDERSTORMS OVER THE NE CARIBBEAN...SEE SPECIAL FEATURES SECTION ABOVE. THE TROPICAL WAVE IN THE W CARIBBEAN IS PRODUCING THE SHOWERS/ THUNDERSTORMS OVER THE W CARIBBEAN...SEE TROPICAL WAVES SECTION ABOVE. AN UPPER RIDGE COVERS THE W CARIBBEAN ANCHORED NEAR 17N82W WHILE THE UPPER RIDGE ASSOCIATED WITH MARIA COVERS THE E CARIBBEAN INDUCING AN INVERTED UPPER TROUGH BETWEEN THAT EXTENDS FROM COLOMBIA NEAR 8N76W TO SW HAITI NEAR 18N74W. THE MONSOON TROUGH EXTENDS ACROSS THE N PORTION OF SOUTH AMERICA ENTERING THE SW CARIBBEAN FROM COLOMBIA NEAR 9N76W ALONG 11N81W INTO THE E PACIFIC REGION ALONG THE NICARAGUA/COSTA RICA BORDER GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS INLAND AND WITHIN 75 NM ALONG THE COAST OF COLOMBIA N OF 9N W OF 71W AND WITHIN 60 NM ALONG THE COAST OF VENEZUELA BETWEEN 64W-67W. WHILE TROPICAL STORM MARIA IS N OF THE VIRGIN ISLANDS AND PUERTO RICO...TROPICAL STORM CONDITIONS WILL CONTINUE N OF 20N W OF 63W TONIGHT. THE W CARIBBEAN TROPICAL WAVE WILL MOVE THROUGH THE GULF OF HONDURAS TONIGHT AND MON. THE TROPICAL ATLC TROPICAL WAVE WILL REACH THE LEEWARD ISLANDS TUE CROSSING INTO THE E CARIBBEAN TUE NIGHT THROUGH THU. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE E CONUS EXTENDS TO ALONG THE EASTERN SEABOARD GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 30N E OF 80W TO THE COAST OF FLORIDA AND INLAND OVER GEORGIA. AN UPPER RIDGE COVERS THE W ATLC EXTENDING FROM E CUBA NEAR HOLGUIN TO BEYOND 32N69W. AN UPPER LOW IS JUST TO THE E NEAR 25N65W WITH BENIGN UPPER LEVEL FEATURES ACROSS THE REMAINDER OF THE ATLC. A BROAD SURFACE RIDGE DOMINATES THE ATLC E OF 60W AND ANCHORED BY A PAIR OF 1024 MB HIGHS...ONE IN THE E ATLC NEAR 29N34W AND ONE IN THE CENTRAL ATLC NEAR 30N52W. A COLD FRONT IS ALONG THE N PERIPHERY OF THE DISCUSSION IN THE E/CENTRAL ATLC BETWEEN THE 1024 MB HIGHS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 31N BETWEEN 40W-46W. TROPICAL STORM MARIA WILL MOVE NW THROUGH EARLY TUE THEN TURN MORE NORTHERLY AND THEN STRENGTHEN TO A HURRICANE AS IT MOVES N OF THE AREA WED NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA THU AND FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW