000 AXNT20 KNHC 142359 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE AUG 14 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM DEAN WAS CENTERED NEAR 11.6N 41.0W...OR ABOUT 1200 NM E OF THE LESSER ANTILLES AT 14/2100 UTC MOVING W AT 18 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. SOME STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS AS DEAN CONTINUES MOVING W OR WNW SOUTH OF A DEEP-LAYERED RIDGE. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. SCATTERED MODERATE CONVECTION IS MOSTLY STRETCHED TO THE W OF THE CENTER FROM 10N-12N BETWEEN 41W-45W. HOWEVER...A NEW CLUSTER OF MODERATE TO STRONG CONVECTION HAS FORMED CLOSER TO THE CENTER WITHIN 30NM OF 11.5N41W. A 1007 MB LOW IS OVER THE SOUTHERN GULF OF MEXICO NEAR 23N91W MOVING WEST-NORTHWEST OR NORTHWEST NEAR 10 KT. DATA FROM AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT EARLIER THIS AFTERNOON INDICATED THAT THE SYSTEM DID NOT YET HAVE A WELL DEFINED CIRCULATION CENTER. HOWEVER...UPPER-LEVEL WINDS CONTINUE TO BECOME MORE FAVORABLE FOR DEVELOPMENT AND A TROPICAL DEPRESSION COULD FORM AT ANY TIME TONIGHT OR TOMORROW. AIRCRAFT DATA INDICATE THAT MAXIMUM WINDS WITH THE LOW ARE CURRENTLY AROUND 25 MPH. ALL INTERESTS IN THE NORTHWESTERN GULF OF MEXICO...INCLUDING THE COASTAL AREAS OF TEXAS AND NORTHEASTERN MEXICO...SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM...AS TROPICAL STORM WARNINGS WOULD LIKELY BE REQUIRED IMMEDIATELY UPON THE INITIATION OF ADVISORIES. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 26W S OF 19N MOVING W 15-20 KT. A 1010 MB LOW IS ALONG THE WAVE AXIS NEAR 15N OR ABOUT 150 NM SW OF THE WRN CAPE VERDE ISLANDS. THIS WAVE CONTINUES TO SHOW UP WELL IN SATELLITE IMAGERY WITH A BROAD AREA OF CYCLONIC TURNING NOTED IN THE SURROUNDING LOW AND MID CLOUDS. THERE IS ONE SMALL CLUSTER OF MODERATE CONVECTION WITHIN 30NM OF 15.5N27W BUT OVERALL SHOWER AND TSTM ACTIVITY REMAINS MINIMAL NEAR THE WAVE. TROPICAL WAVE PREVIOUSLY ALONG 50W WAS ADJUSTED SLIGHTLY TO THE WEST TO 54W S OF 17N...MOVING W 10-15 KT. THE RELOCATION WAS WARRANTED DUE TO THE EVIDENCE OF AN INVERTED V SHAPE IN THE SURROUNDING LOWER TO MID LEVEL CLOUDS. IN ADDITION THE WAVE SHOWS UP WELL AS A WWD PROPAGATING SURGE OF MOISTURE IN THE UW-CIMSS TPW PRODUCT. THERE DOES APPEAR TO BE A SMALL CYCLONIC SWIRL JUST TO THE W OF T.S. DEAN NEAR 11N49W. I SUSPECT THIS IS EITHER NORMAL VORTICITY EMBEDDED IN THE ITCZ...OR THE LOW AMPLITUDE WAVE THAT WAS DROPPED YESTERDAY BEGINNING TO SHOW ITS FACE AGAIN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 13N24W 13N37W 10N48W 10N56W 9N63W. ISOLATED CLUSTERS OF MODERATE CONVECTION ARE FROM 8N-13N BETWEEN 25W-33W. OUTSIDE OF THIS ACTIVITY AND THAT ASSOCIATED WITH T.S. DEAN...NOT MUCH ELSE IS NOTED. DISCUSSION... GULF OF MEXICO... THE MAIN FOCUS CONTINUES TO BE THE SPECIAL FEATURE IN THE SRN GULF. THIS SYSTEM...IN ADDITION TO DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LOW MOVING THROUGH DEEP SOUTH TEXAS AND AN UPPER HIGH OVER THE NRN GULF NEAR 27N88W...IS PRODUCING WIDESPREAD CLOUDINESS/SHOWERS AND ISOLATED TSTMS OVER MUCH OF THE GULF S OF 28N BETWEEN 85W-95W. THIS MOISTURE WILL CONTINUE MOVING WNW/NW TOWARDS THE NE MEXICO AND TEXAS COASTS OVER THE NEXT DAY OR SO. THE OTHER INTERESTING FEATURE THIS EVENING IS THE SQUALL LINE MOVING QUICKLY N FROM WRN CUBA THROUGH THE STRAITS OF FLORIDA. CARIBBEAN SEA... THE CARIBBEAN IS QUIET IN COMPARISON TO THE GULF ALTHOUGH ISOLATED TSTMS PERSIST IN THE FAR NW AND SW PORTIONS. TRADES ARE MOSTLY MODERATE 10-20 KT AND BEND MORE SE IN THE NW PORTION BEHIND THE LOW IN THE GULF. SIMILAR TRADES EXPECTED THROUGH THU BUT T.S. DEAN MAY AFFECT THE ERN PORTION LATER IN THE WEEK AND INTO THE WEEKEND. INTERESTS IN THE LESSER ANTILLES SHOULD MONITOR THE PROGRESS OF DEAN. UPPER NE FLOW AROUND RIDGING FROM THE GULF DOMINATES THE NW PORTION OF THE CARIB TONIGHT WHILE UPPER CYCLONIC FLOW IS OVER THE ERN PORTION...AROUND AN UPPER LOW JUST N OF PUERTO RICO. ATLANTIC OCEAN... A REMNANT FRONTAL TROUGH EXTENDS SW FROM 31N64W TO THE BAHAMAS NEAR 26N78W. THIS ALONG WITH UPPER DIFFLUENCE BETWEEN AN UPPER TROUGH OFF THE EASTERN SEABOARD AND A NARROW RIDGE EXTENDING ENE FROM THE CENTRAL BAHAMAS TO 27N68W...IS SUPPORTING WIDESPREAD CLOUDINESS...SCATTERED SHOWERS...AND ISOLATED TSTMS WITHIN 90NM EITHER SIDE OF THE LINE 24N80W 26N71W 32N62W. SKIES ARE MUCH CLEARER BEHIND THE BOUNDARY OFFSHORE NORTH FLORIDA. DEEP LAYER RIDGING DOMINATES MUCH OF THE REMAINDER OF THE CENTRAL AND EASTERN ATLC WHICH IS PUSHING T.S. DEAN QUICKLY TO THE W. BENIGN UPPER LOWS NOTED NEAR 32N46W AND 26N30W. A 1024 MB SFC HIGH NEAR 33N39W HAS MODERATE TRADES AND FAIR WEATHER N OF 18N E OF 45W. NE FLOW REMAINS A BIT STRONGER OFF THE COAST OF NW AFRICA WHERE A TIGHTER GRADIENT EXISTS BETWEEN RIDGING AND THERMAL TROUGHING OVER THE LAND. FIND DETAILS ON T.S. DEAN IN SPECIAL FEATURE SECTION ABOVE. $$ WILLIS