000 AXNT20 KNHC 011157 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE SEP 01 2009 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A 1007 MB LOW ROUGHLY CENTERED NEAR 16N56W OR ABOUT 240 NM E OF THE LEEWARD ISLANDS CONTINUES TO SHOW SIGNS OF ORGANIZATION BUT NOT A WELL-DEFINED SURFACE CIRCULATION CENTER. A SURFACE TROUGH EXTENDS FROM 20N52W THROUGH THE SURFACE LOW TO 11N63W. SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN A 60 NM RADIUS OF 16.5N53.5W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 14N-20N BETWEEN 51W-55W AND CLUSTERS OF SIMILAR CONVECTION WITHIN 45 NM OF LINE FROM 14N53W TO 12N57W. THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION OR TROPICAL STORM AT ANY TIME OVER THE NEXT COUPLE OF DAYS AS IT MOVES WNW NEAR 8 KT. INTERESTS IN THE LEEWARD ISLANDS...THE U.S. AND BRITISH VIRGIN ISLANDS...AND PUERTO RICO SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 17N31W TO 9N29W MOVING W NEAR 10 KT. WAVE REMAINS ALONG THE LEADING EDGE OF DEEP LAYERED MOISTURE AS INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...THIS WAVE IS ALSO EMBEDDED WITHIN SAHARAN DUST THUS LIMITING ANY SHOWERS/CONVECTION. TROPICAL WAVE IS ALONG 81W/82W S OF 17N MOVING W NEAR 15 KT. THIS WAVE REMAINS EMBEDDED WITHIN AN AREA OF LIGHT MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY AND WITH DRY STABLE AIR AT THE LOWER LEVELS...THERE ARE NO SHOWERS/CONVECTION. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 14N16W 9N23W 7N36W 10N47W 13N53W. THE ITCZ IS BEING DISTORTED BY THE LOW IN THE SPECIAL FEATURES SECTION ABOVE. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 90/120 NM OF LINE FROM 19N18W TO 13N22W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT CONTINUES TO MEANDER ALONG THE N GULF COAST AND AT 0600 UTC EXTENDS INTO THE GULF WATERS OVER PENSACOLA FLORIDA ACROSS THE MISSISSIPPI DELTA OF LOUISIANA TO INLAND OVER OVER TEXAS NEAR CORPUS CHRISTI. A SURFACE TROUGH IS TO THE S OF THE FRONT EXTENDING FROM 28N86W TO 27N94W WITH A SECOND TROUGH FURTHER TO THE E EXTENDING FROM THE W ATLC ACROSS CENTRAL FLORIDA BETWEEN MELBOURNE AND DAYTONA BEACH ACROSS TO TAMPA CONTINUING SW TO 26N85W. A BROAD UPPER RIDGE ANCHORED IN THE E PACIFIC EXTENDS ACROSS MEXICO INTO THE GULF NEAR TAMPICO TO NEAR 27N85W WITH A SHORTWAVE UPPER TROUGH OVER THE FLORIDA PENINSULA EXTENDING FROM A BROAD UPPER TROUGH COVERING THE E HALF OF THE U.S. THROUGH SW GEORGIA TO THE UPPER FLORIDA KEYS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS THE N GULF N OF 26N WITH CLUSTERS OF SIMILAR ACTIVITY S OF 21N INTO THE BAY OF CAMPECHE BETWEEN 92W-96W. ISOLATED SHOWERS DOT THE REMAINDER OF THE GULF WATERS. CARIBBEAN SEA... AN UPPER LEVEL RIDGE COVERS THE W AND CENTRAL CARIBBEAN W OF 76W ANCHORED NEAR 17N82W. DIFFLUENCE ALOFT IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ACROSS THE NW CARIBBEAN N OF 17N W OF 77W TO INLAND OVER CUBA...CENTRAL AMERICA...AND THE YUCATAN PENINSULA. AN UPPER TROUGH OVER THE W/CENTRAL ATLC EXTENDS S OVER THE GREATER ANTILLES TO THE COAST OF VENEZUELA/COLOMBIA BETWEEN THE E CUBA AND THE VIRGIN ISLANDS PRODUCING CLUSTERS OF ISOLATED SHOWERS N OF 16N TO OVER HISPANIOLA AND THROUGH THE WINDWARD PASSAGE. MODERATE/STRONG EASTERLY TRADE WINDS CONTINUE ACROSS THE AREA. LOW MENTIONED IN THE SPECIAL FEATURES IS EXPECTED TO MOVE JUST TO THE NE OF THE LEEWARD/VIRGIN ISLANDS OVER THE NEXT COUPLE OF DAYS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE MOVING OVER THE LESSER ANTILLES MAINLY FROM 13N-15N W OF 60W WITH ISOLATED SHOWERS ELSEWHERE OVER THE ISLANDS. ATLANTIC OCEAN... THE MAIN FOCUS THIS MORNING IS THE LOW E OF THE LESSER ANTILLES THAT HAS THE POTENTIAL OF DEVELOPING...SEE SPECIAL FEATURES ABOVE. IN THE W ATLC...A SURFACE TROUGH EXTENDS FROM 30N78W ACROSS THE FLORIDA PENINSULA BETWEEN MELBOURNE AND DAYTONA BEACH CONTINUING INTO THE GULF OF MEXICO. NARROW UPPER RIDGE IS OVER THE FAR W ATLC EXTENDING FROM W CUBA NEAR 23N81W TO 31N75W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS W OF A LINE FROM FLORIDA NEAR FORT LAUDERDALE NEAR 26N80W TO BEYOND 32N72W TO 80W. AN UPPER TROUGH EXTENDS ACROSS THE ATLC BASIN FROM THE E ATLC THROUGH 32N19W AND A SERIES OF UPPER LOWS CENTERED NEAR 30N22W...26N341...32N61W... TO AN ILL-DEFINED LOW NEAR 25N71W. A SURFACE TROUGH IS ALONG THE WESTERN BOUNDARY OF THIS UPPER TROUGH EXTENDING FROM THE WINDWARD PASSAGE NEAR 20N74W ACROSS THE TURKS AND CAICOS ALONG 25N73W TO 30N71W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE E OF THE SURFACE TROUGH WITHIN 150 NM OF LINE FROM 20N71W TO 26N67W AND N OF 31N BETWEEN 55W-63W. OTHERWISE THE REMAINDER OF THE ATLC BASIN REMAINS TRANQUIL AGAIN THIS MORNING AS A SURFACE RIDGE CONTINUES TO DOMINATE THE BASIN BETWEEN 20W-70W ANCHORED BY A 1027 MB HIGH WELL N OF THE REGION WSW OF THE AZORES. $$ WALLACE