000 AXNT20 KNHC 251820 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE SEP 25 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 1745 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM KAREN AT 25/1500 UTC WAS NEAR 10.8N 38.7W OR ABOUT 1316 NM/2440 KM EAST OF THE WINDWARD ISLANDS. KAREN IS MOVING WEST-NORTHWEST 13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. PLEASE READ THE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/ WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. KAREN IS EXHIBITING SOME BANDING FEATURES ON VISIBLE SATELLITE IMAGERY...BUT THE DEEP CONVECTION IS NOT THAT STRONG OR CONCENTRATED NEAR THE CENTER. THE ENVIRONMENT TO THE WEST OF KAREN IS QUESTIONABLE FOR STRENGTHENING. THE UPPER LEVEL OUTFLOW OF KAREN IS BEING RESTRICTED OVER THE NORTHWESTERN QUADRANT DUE TO A NEARBY UPPER-LEVEL CYCLONIC SHEAR AXIS. GLOBAL MODELS DEPICT A COUPLE OF UPPER-LEVEL TROUGHS OVER THE CENTRAL SUBTROPICAL ATLANTIC DURING THE NEXT FEW DAYS THAT SHOULD CAUSE INCREASING SOUTHWESTERLY VERTICAL SHEAR OVER KAREN. SCATTERED STRONG SHOWERS AND THUNDERSTORMS IN A BAND FROM 8N TO 10N BETWEEN 36W AND 38W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 9N TO 13N BETWEEN 35W AND 41W. SATELLITE IMAGES INDICATE THAT A TROPICAL DEPRESSION MAY BE FORMING IN THE SOUTHWESTERN GULF OF MEXICO ABOUT 180 MILES EAST OF TAMPICO MEXICO. AN AIR FORCE RECONNAISSANCE PLANE IS SCHEDULED TO INVESTIGATE THE AREA THIS AFTERNOON. THIS SYSTEM IS EXPECTED TO MOVE LITTLE DURING THE NEXT 24 HOURS. A 1009 MB LOW PRESSURE CENTER IS NEAR 22.5N95W...ALONG A TROUGH THAT RUNS FROM MEXICO NEAR 19N91W IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO TO THE LOW CENTER...AND TO 26N96W. SCATTERED TO NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 20N TO 22N BETWEEN 94W AND 96W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE ELSEWHERE FROM 20N TO 24N BETWEEN 86W AND 96W. A CONTINUALLY-WEAKENING MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN THE GULF OF MEXICO WATERS JUST OFF THE UPPER TEXAS COAST. ISOLATED MODERATE SHOWERS ARE FROM 25N TO 30N BETWEEN 90W AND 94W. AN UPPER LEVEL RIDGE IS ON TOP OF THE AREA OF THE 1009 MB LOW PRESSURE CENTER AND TROUGH. ...TROPICAL WAVES... AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 62W MOVING WEST 10 TO 15 KT. A 1012 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 17N. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN A 30 NM RADIUS OF 16N63.5W. OTHER STRONG SHOWERS ARE FROM 16N TO 17N BETWEEN 61W AND 64W. ISOLATED MODERATE SHOWERS FROM 20N TO 24N BETWEEN 59W AND 62W. THIS SYSTEM HAS CHANGED LITTLE IN ORGANIZATION DURING THE PAST SEVERAL HOURS AND UPPER-LEVEL WINDS ARE BECOMING LESS FAVORABLE FOR DEVELOPMENT. THE LOW SHOULD MOVE TOWARD THE NORTHWEST...BRINGING SQUALLY WEATHER TO THE NORTHERN LEEWARD ISLANDS...THE BRITISH AND US VIRGIN ISLANDS AND PUERTO RICO DURING THE NEXT 24 HOURS. RESIDENTS IN THESE AREAS SHOULD CONTINUE TO MONITOR THE PROGRESS OF THIS SYSTEM. A TROPICAL WAVE IS ALONG 92W SOUTH OF 17N MOVING WEST 10 TO 15 KT. NO DEEP CONVECTIVE PRECIPITATION THAT IS RELATED TO THIS WAVE IS OCCURRING IN THE GULF OF MEXICO NOR IN MEXICO OR THE REST OF CENTRAL AMERICA. ...THE ITCZ... 8N12W 6N16W 10N34W 8N40W 4N50W 6N58W. SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS FROM 4N TO 8N BETWEEN 20W AND 30W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 6N TO 10N BETWEEN AFRICA AND 16W. DISCUSSION... THE REST OF THE GULF OF MEXICO AWAY FROM THE 1009 MB LOW PRESSURE CENTER IN THE SOUTHWESTERN CORNER OF THE AREA... A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS JUST OFF THE COAST OF SOUTHWESTERN FLORIDA. A TROUGH EXTENDS FROM THIS CYCLONIC CENTER INTO THE NORTHWESTERN CARIBBEAN SEA. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 20N TO CUBA AND THE YUCATAN CHANNEL BETWEEN 80W AND THE YUCATAN PENINSULA. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORM ALSO ARE OVER THE BAHAMAS FROM 23N TO 26N BETWEEN 74W AND 81W...INCLUDING IN THE STRAITS OF FLORIDA. THE CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS JUST SOUTH OF JAMAICA NEAR 17N77W. UPPER LEVEL ANTICYCLONIC NORTHERLY WIND FLOW MOVES FROM THE GULF OF MEXICO...AND ULTIMATELY BLENDS INTO THE FLOW ON THE WESTERN SIDE OF THE 17N77W CYCLONIC CENTER. A TROUGH EXTENDS FROM THE 17N77W CYCLONIC CENTER TO THE COAST OF COSTA RICA/PANAMA. STRONG SHOWERS AND THUNDERSTORMS HAVE MOVED OUT OF THE GULF OF URABA AWAY FROM COLOMBIA AND NOW ARE FROM 10N TO 11.5N BETWEEN 76W AND 78W. LINGERING SHOWERS ARE POSSIBLE IN THE GULF OF URABA. WARMING CLOUD TOP TEMPERATURES AND DISSIPATING PRECIPITATION ARE ON THE SOUTHERN SIDE OF PANAMA AND ITS COASTAL WATERS. THE ITCZ PASSES RIGHT ON TOP OF PANAMA. ISOLATED MODERATE SHOWERS ARE WITHIN 30 NM ON EITHER SIDE OF THE LINE FROM THE MONA PASSAGE TO 15N71W ON THE EASTERN SIDE OF THE 17N77W CYCLONIC CENTER. THIS PRECIPITATION IS OCCURRING IN AN AREA OF UPPER LEVEL DIFFLUENT FLOW. UPPER LEVEL ANTICYCLONIC COVERS THE REST OF THE CARIBBEAN SEA TO THE EAST OF THE 17N77W CYCLONIC CENTER. THE ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE WESTERN ATLANTIC OCEAN NEAR 29N60W TO A 29N77W CYCLONIC CIRCULATION CENTER... TO THE CYCLONIC CENTER OFF THE SOUTHWEST FLORIDA COAST IN THE GULF OF MEXICO. BROAD LARGE-SCALE CYCLONIC FLOW ON WATER VAPOR IMAGERY COVERS THE ATLANTIC OCEAN NORTH OF 20N WEST OF 60W. THE SURFACE PRESSURES ARE NOT FALLING AT THIS TIME AND ANY TYPE OF ADDITIONAL DEVELOPMENT WILL BE SLOW TO OCCUR. IT IS POSSIBLE THAT THIS SYSTEM MAY BRING LOCALLY HEAVY RAINS TO SOUTH FLORIDA AND THE FLORIDA KEYS DURING THE NEXT DAY OR TWO. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS ARE FROM 24N TO 32N ELSEWHERE BETWEEN 60W AND 80W. A SURFACE TROUGH IS ALONG 29N66W 27N67W 24N67W. THE BASE OF A DEEP LAYER CENTRAL ATLANTIC OCEAN TROUGH STILL IS NORTH OF 30N. THIS TROUGH SUPPORTS A COLD FRONT THAT GOES FROM 32N60W...ACROSS BERMUDA TO 32N68W. A PERSISTENT SURFACE TROUGH PASSES THROUGH 32N40W 27N50W TO 26N56W. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS ARE WITHIN 60 TO 90 NM ON EITHER SIDE OF 31N38W 28N43W 27N52W 27N57W. A SURFACE TROUGH IS ALONG 51W/52W FROM 12N TO 18N. THIS TROUGH IS THE REMNANT OF A SURFACE LOW PRESSURE CENTER FROM 24 HOURS THAT ULTIMATELY DISSIPATED INTO AN OPEN TROUGH. ISOLATED MODERATE SHOWERS WITHIN A 15 NM RADIUS OF 14N51.5W. A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH 31N20W 22N22W TO 14N24W NEAR THE CAPE VERDE ISLANDS. A RIDGE IS ALONG 24N41W BEYOND 32N30W. $$ MT