000 AXNT20 KNHC 121754 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM PATTY IS CENTERED NEAR 25.5N 72.0W AT 12/1500 UTC OR ABOUT 240 NM ENE OF THE CENTRAL BAHAMAS MOVING NE AT 2 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC. THE LOW LEVEL CENTER IS BECOMING EXPOSED TO THE SW OF THE DEEP CONVECTION. CLUSTERS OF SCATTERED/ISOLATED STRONG CONVECTION ARE FROM 25N-28N BETWEEN 65W-72W. A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A WEAK 1006 MB LOW IS CENTERED W OF THE LESSER ANTILLES ABOUT 87 NM W OF DOMINICA. AN UPPER RIDGE IS TO THE E OF THE LESSER ANTILLES PROVIDING DIFFLUENCE ALOFT ENHANCING AN AREA OF SCATTERED/NUMEROUS STRONG CONVECTION WITHIN A 120 NM RADIUS OF 14.5N60.5W INCLUDING THE ISLANDS FROM SAINT LUCIA TO DOMINICA. SURFACE OBSERVATIONS INDICATE THAT THIS SYSTEM IS PRODUCING WINDS TO TROPICAL STORM FORCE IN RAINBANDS...HOWEVER SATELLITE IMAGERY AND SURFACE OBSERVATIONS STILL SUGGEST THAT THE LOW LACKS A CLOSED SURFACE CIRCULATION. UPPER LEVEL WINDS ARE EXPECTED TO BECOME MORE CONDUCIVE FOR DEVELOPMENT AND IT IS LIKELY THAT A TROPICAL DEPRESSION OR TROPICAL STORM WILL FORM DURING THE NEXT DAY OR TWO. IF THIS OCCURS...A TROPICAL STORM WARNING WOULD BE REQUIRED FOR PORTIONS OF THE LEEWARD ISLANDS. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES NW OR N-NW AT 9 TO 13 KT. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM THE CAPE VERDE ISLANDS NEAR 16N24W TO 6N27W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM OF LINE FROM 5N16W TO 10N34W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 14N16W TO E OF THE TROPICAL WAVE NEAR 12N20W. THE ITCZ AXIS BEGINS W OF THE TROPICAL WAVE NEAR 7N31W ALONG 8N41W TO 9N52W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120 NM S OF THE ITCZ BETWEEN 39W-44W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE COVERS THE GULF THIS AFTERNOON W OF 86W ANCHORED INLAND OVER MEXICO NEAR MEXICO CITY EXTENDING A RIDGE AXIS NNE OVER TEXAS AND THE CENTRAL PLAIN STATES. AN UPPER TROUGH COVERS THE REMAINDER OF THE GULF E OF 86W WITH THE TROUGH AXIS IN THE W ATLC. DRY STABLE UPPER AIR DOMINATES MOST OF THE GULF. A WEAK SURFACE TROUGH IS IN THE SW GULF EXTENDING FROM 22N96W TO THE S COAST OF MEXICO NEAR 18N94W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM ALONG THE COAST OF TEXAS AND MEXICO S OF CORPUS CHRISTI TEXAS AND W OF COATZACOALCOS MEXICO. A SURFACE RIDGE IS BUILDING S OVER THE GULF ANCHORED OVER CENTRAL GEORGIA. DRIER AIR HAS SETTLED OVER THE AREA IN WAKE OF THE RECENT FRONTAL PASSAGE LEAVING THE REMAINDER OF THE GULF WITH FAIR WEATHER THIS AFTERNOON. SURFACE RIDGE WILL REMAIN OVER THE GULF SHIFTING E ON MON MAKING WAY FOR A WEAK FRONTAL TROUGH TO SWEEP ACROSS THE FAR N GULF MON AND TUE. A SECOND SURFACE RIDGE WILL MOVE E IN WAKE OF THE FRONTAL TROUGH. CARIBBEAN SEA... A WEAK 1006 MB LOW IS W OF THE LESSER ANTILLES...SEE SPECIAL FEATURES ABOVE. THE UPPER TROUGH OVER THE E GULF OF MEXICO DIPS S OVER THE NW CARIBBEAN N OF 17N W OF 76W TO OVER THE YUCATAN PENINSULA WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AT THE BASE OF THE UPPER TROUGH FROM 15N-19N W OF 82W TO INLAND OVER HONDURAS AND THE YUCATAN PENINSULA. SIMILAR ACTIVITY IS N OF JAMAICA TO INLAND OVER CUBA BETWEEN 74W-78W. THE UPPER RIDGE OVER THE W GULF OF MEXICO EXTENDS A RIDGE AXIS W ACROSS CENTRAL AMERICA INTO THE CARIBBEAN NEAR THE TIP OF NICARAGUA/HONDURAS TO 16N74W. AN UPPER LOW IS S OF THE MONA PASSAGE NEAR 16N68W COVERING THE REMAINDER OF THE CARIBBEAN AND GENERATING ISOLATED SHOWERS/THUNDERSTORMS N OF 16N BETWEEN 64W-69W INCLUDING PUERTO RICO AND THE VIRGIN ISLANDS. AN UPPER RIDGE OVER THE W TROPICAL ATLC IS GENERATING A BROAD AREA OF SCATTERED/NUMEROUS SHOWERS WITH SCATTERED THUNDERSTORMS FROM OVER THE LESSER ANTILLES EASTWARD AND INCLUDING THE AREA ASSOCIATED WITH THE 1006 MB LOW IN THE SPECIAL FEATURES. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N75W ALONG 11N80W THEN ACROSS COSTA RICA INTO THE E PACIFIC REGION NEAR 10N85W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 11N ALONG THE COAST OF COLOMBIA AND INLAND OVER W PANAMA. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH FAIR WEATHER THIS AFTERNOON. STRONG WINDS...ROUGH SEAS...AND NUMEROUS SQUALLS WILL ACCOMPANY THE 1006 MB LOW OVER THE LEEWARD AND VIRGIN ISLANDS AS THIS LOW MOVES NNW TO OVER THE VIRGIN ISLANDS SAT MORNING AND INTO THE W ATLC E OF THE TURKS AND CAICOS BY SUN MORNING. ATLANTIC OCEAN... T.S. PATTY REMAINS E OF THE BAHAMA ISLANDS THIS AFTERNOON...SEE SPECIAL FEATURES ABOVE. THE UPPER TROUGH OVER THE E GULF OF MEXICO AND THE NW CARIBBEAN EXTENDS TO OVER THE FAR W ATLC WITH A DISSIPATING STATIONARY FRONT ENTERING THE REGION NEAR 32N69W TO N OF T.S. PATTY NEAR 28N71W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 28N BETWEEN 65W AND THE FRONTAL BOUNDARY. SIMILAR ACTIVITY IS WITHIN 120 NM OF LINE FROM OVER CUBA NEAR 21N75W TO OVER THE TURKS AND CAICOS TO NEAR 23N74W. THE SURFACE RIDGE BUILDING S OVER THE GULF OF MEXICO COVERS THE W ATLC W OF 77W ANCHORED OVER CENTRAL GEORGIA AND LEAVING THE REMAINDER OF THE W ATLC W OF THE T.S. PATTY WITH FAIR WEATHER THIS AFTERNOON. AN UPPER LOW IS IN THE CENTRAL ATLC NEAR 27N58W GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 25N-31N BETWEEN 53W-59W. A SECOND UPPER LOW IS IN THE E ATLC CENTERED NEAR 23N31W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 21N-24N BETWEEN 31W-34W. THE REMAINDER OF THE ATLC BASIN N OF THE TROPICS IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH JUST N OF THE DISCUSSION AREA NEAR 34N42W. AN UPPER RIDGE IN THE W TROPICAL ATLC EXTENDS FROM ALONG 53W FROM 10N-23N PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 10N-17N BETWEEN 56W-62W INCLUDING A PORTION OF THE LESSER ANTILLES. ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS COVER THE REMAINDER OF THE AREA FROM 7N-21N BETWEEN 41W-55W. PATTY WILL DRIFT SLOWLY E AND WEAKEN TO TROPICAL DEPRESSION LATE THIS AFTERNOON THEN WEAKEN TO A REMNANT LOW CENTERED BY SUN NEAR 23.5N 75.0W. THE 1006 MB LOW WILL MOVE OUT OF THE NE CARIBBEAN LATE SAT/EARLY SUN TO E OF THE CENTRAL BAHAMAS BY MON MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW