000 AXNT20 KNHC 141733 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM DEAN...UPGRADED FROM TROPICAL DEPRESSION FOUR AT 1500 UTC...IS CENTERED NEAR 11.7N 39.4W AT 14/1500 UTC MOVING W AT 20 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. THE ASSOCIATED DEEP CONVECTION REMAINS DISPLACED TO THE WEST AND SOUTH OF THE CENTER DUE TO EASTERLY SHEAR OVER THE SYSTEM. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 9N-12N BETWEEN 38W-41W. DEAN IS FORECAST TO GRADUALLY STRENGTHEN AS THE EASTERLY SHEAR DECREASES. THE SYSTEM WILL CONTINUE TO MOVE IN A GENERALLY WESTWARD MOTION ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYER RIDGE WITH A GRADUAL DECREASE IN FORWARD SPEED DURING THE NEXT COUPLE OF DAYS. A 1007 MB LOW IS CENTERED NEAR 23N90W...APPROXIMATELY 80 NM NORTH OF THE YUCATAN PENINSULA. THE ASSOCIATED TROPICAL WAVE IS SOUTH OF 19N ALONG 90W/91W. THE SYSTEM CONTINUES TO PRODUCE WIDESPREAD CLOUDINESS WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE CENTRAL GULF...S OF 28N BETWEEN 85W-92W. THE SYSTEM HAS BECOME BETTER ORGANIZED THIS MORNING AND TROPICAL DEPRESSION FORMATION IS POSSIBLE LATER THIS AFTERNOON AS THE LOW MOVES TO THE WNW NEAR 10-15 KT. INTERESTS IN THE NORTHWESTERN GULF OF MEXICO SHOULD CONTINUE TO MONITOR THE PROGRESS OF THIS SYSTEM. A RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THIS SYSTEM THIS AFTERNOON. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 25W S OF 19N MOVING W 15-20 KT WITH A 1010 MB LOW JUST SW OF THE CAPE VERDE ISLANDS NEAR 15N25W. THIS WAVE HAS A WELL DEFINED LOW/MID LEVEL ROTATION WITH SCATTERED MODERATE CONVECTION FROM 11N-13N BETWEEN 23W-27W. TROPICAL WAVE IS ALONG 50W S OF 16N MOVING W 15 KT. WEAK LOW/MID LEVEL ROTATION IS EMBEDDED WITHIN THE ITCZ WITH LOW AMPLITUDE INVERTED-V CURVATURE OBSERVED. NO ASSOCIATED SHOWER ACTIVITY/CONVECTION. A TROPICAL WAVE ASSOCIATED WITH THE 1007 MB LOW IN THE SPECIAL FEATURES SECTION HAS MOVED INTO THE EAST PACIFIC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 12N30W 13N35W 10N46W 10N60W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE SOUTH OF THE ITCZ FROM 3N-10N E OF 27W. ADDITIONAL CONVECTION ASSOCIATED WITH TROPICAL STORM DEAN IS DESCRIBED IN THE SPECIAL FEATURES SECTION ABOVE. DISCUSSION... GULF OF MEXICO... THE MAIN FOCUS THIS MORNING CONTINUES TO BE THE 1007 MB SFC LOW JUST OFF THE N COAST OF THE YUCATAN AS DESCRIBED IN THE SPECIAL FEATURES SECTION. AN UPPER HIGH NEAR 24N87W...E OF THE SURFACE LOW...IS ENHANCING THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE LOW. A MID/UPPER LEVEL LOW IS IN THE NW GULF NEAR 26N97W AND IS SUPPORTING A BAND OF THUNDERSTORMS ALONG THE COAST FROM THE MEXICO/TEXAS BORDER TO CORPUS CHRISTI. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS EXTEND FROM THE COAST TO 92W NORTH OF 25N. ISOLATED SHOWERS/THUNDERSTORMS CONTINUE TO PERSIST IN THE BAY OF CAMPECHE S OF 21N. CARIBBEAN SEA... A CLUSTER OF MODERATE CONVECTION WITH EMBEDDED THUNDERSTORMS IS MOVING OVER THE CARIBBEAN S OF 13N FROM A 1010 MB SFC LOW CENTERED OVER COLOMBIA. AN UPPER HIGH N OF THE YUCATAN CHANNEL IS GIVING THE W CARIBBEAN WIDESPREAD CLOUDINESS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MAINLY W OF 82W. DRY STABLE AIR AND MODERATE TRADES DOMINATE THE REMAINDER OF THE CARIBBEAN. ATLANTIC OCEAN... A DEEP LAYERED TROUGH OVER THE W ATLC EXTENDS SOUTH TO 27N. A SURFACE TROUGH STRETCHES FROM THE SOUTHERN TIP OF FRONTAL BOUNDARY NEAR 31N66W TO 28N77W GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 100/150 NM OF LINE FROM THE BAHAMAS NEAR 26N78W NE TO BEYOND 32N60W. A LARGE CLUSTER OF THUNDERSTORMS IS FROM 29N-32N BETWEEN 75W-79W BETWEEN THE SFC TROUGH AND A COLD FRONT NORTH OF THE AREA. A SURFACE RIDGE ANCHORED BY A 1025 MB SFC HIGH NEAR 33N36W DOMINATES THE CENTRAL AND EAST ATLC PROVIDING FAIR WEATHER CLOUDS AND LITTLE CHANCE OF SHOWER ACTIVITY EAST OF 57W. SEE SPECIAL FEATURES SECTION ABOVE FOR INFORMATION ON TROPICAL STORM DEAN. $$ WADDINGTON