000 AXNT20 KNHC 152345 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU MAY 15 2008 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. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 24W/25W S OF 11N MOVING W 10-15 KT. SATELLITE IMAGERY SHOWS A BROAD AREA OF LOW LEVEL CYCLONIC TURNING ALONG THE WAVE NEAR 5N. SCATTERED SHOWERS AND TSTMS ARE WITHIN 200 NM AHEAD OF THE WAVE AXIS. MORE SHOWER AND TSTM ACTIVITY IS OBSERVED BEHIND THE WAVE AXIS FROM 2N-10N BETWEEN 15W AND 22W. THIS CONVECTIVE ACTIVITY IS BEING ENHANCED BY UPPER DIFFLUENCE ASSOCIATED WITH AN UPPER-LEVEL HIGH LOCATED NEAR 9N18W. A TROPICAL WAVE IS ALONG 48W S OF 11N MOVING W 10-15 KT. AN INVERTED-V PATTERN IS PRETTY WELL DEFINED ON SATELLITE IMAGERY WITH SOME LOW-LEVEL CYCLONIC TURNING ALONG THE WAVE AXIS NEAR 7N. SCATTERED SHOWERS AND TSTMS ARE WITHIN 160 NM EITHER SIDE OF THE AXIS S OF 8N. THE SSMI-DERIVED TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS SUPPORTS THE POSITION OF THE WAVE. THE THIRD TROPICAL WAVE IS OVER WESTERN VENEZUELA/EASTERN COLOMBIA WITH IT AXIS ALONG 71W/72W. A SMALL BULGE OF MOISTURE ON THE MIMIC TPW ANIMATION BETWEEN THE ABC ISLANDS AND THE GUAJIRA PENINSULA CONFIRMS THE PRESENCE OF THIS WAVE THAT IS ENHANCING SOME SHOWER/TSTM ACTIVITY ACROSS THE AREA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 7N23W 5N26W 3N36W 5N47W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE OVER SIERRA LEONE AND GUINEA. THE REST OF THE CONVECTIVE ACTIVITY IS MAINLY ASSOCIATED WITH THE TROPICAL WAVES PREVIOUSLY DESCRIBED. ...DISCUSSION... GULF OF MEXICO... THE GULF REMAINS UNDER THE INFLUENCE OF A RIDGE...BOTH AT THE SURFACE AND ALOFT. A COASTAL TROUGH IS ON THE 21Z MAP EXTENDING FROM 27N96W TO NEAR TAMPICO MEXICO. THIS PATTERN IS PRODUCING SOUTHERLY WINDS OF 15 TO 20 KT OVER MOST OF THE GULF. A COLD FRONT IS CURRENTLY MOVING OFF THE TEXAS COAST. THE FRONT WILL EXTEND FROM NORTH FLORIDA TO NEAR 25N91W TO BAY OF CAMPECHE FRIDAY NIGHT AND BECOME STATIONARY AND WEAKEN ON SATURDAY. AHEAD OF THE FRONT...A SQUALL LINE IS MOVING EWD ACROSS THE FLORIDA PANHANDLE. IN THE UPPER LEVELS...A LARGE UPPER HIGH CENTERED OVER THE NW CARIBBEAN DOMINATES THE ENTIRE GULF REGION AND THE STATE OF FLORIDA WHILE A DEEP LAYERED TROUGH IS OVER THE SW CONUS AND MEXICO. SWLY AND THEN WLY WINDS BETWEEN THESE TWO UPPER LEVEL FEATURES ARE TRANSPORTING ABUNDANT UPPER LEVEL MOISTURE FROM THE EPAC THROUGH MEXICO INTO THE NORTHERN GULF WATERS. CARIBBEAN SEA... THE TAIL END OF A COLD FRONT FROM THE CENTRAL ATLC REMAINS WELL DEFINED ACROSS HISPANIOLA AND JAMAICA WHERE IT IS PRODUCING BROKEN LOW/MID CLOUDS AND MAINLY LIGHT SHOWERS. THE REMAINDER OF THE BASIN IS PRETTY QUIET DUE TO THE PRESENCE OF A MID/UPPER RIDGE OVER THE WEST AND CENTRAL CARIBBEAN AND UPPER TROUGHING OVER THE E CARIBBEAN. THIS UPPER PATTERN IS PRODUCING MODERATE TO STRONG SUBSIDENCE SUPPRESSING THE DEVELOPMENT OF ANY SIGNIFICANT CONVECTION. A PLUME OF TRANSVERSE HIGH CLOUDS IS OVER THE SW CARIBBEAN. CONVECTION HAS DEVELOPED AGAIN EARLY THIS EVENING NEAR THE COLOMBIA/PANAMA BORDER DUE TO THE CLOSE PROXIMITY OF THE EPAC ITCZ. WEAK HIGH PRES N OF THE AREA COMBINED WITH THE ABOVE MENTIONED FRONTAL SYSTEM IS PRODUCING FAIRLY MODEST TRADE WINDS ACROSS THE REGION. THESE WINDS ARE EXPECTED TO INCREASE SLIGHTLY DURING THE UPCOMING WEEKEND AS THE ATLC RIDGE EXTENDS WWD ACROSS THE BASIN. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH OVER THE CENTRAL ATLC SUPPORTS A COLD FRONT THAT EXTENDS FROM A 1010 MB LOW NEAR 33N56W TO HISPANIOLA. LOW-LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY COUPLED WITH A DIFFLUENT PATTERN ALOFT IS PRODUCING A 200 NM WIDE BAND OF SCATTERED SHOWERS AND TSTMS E OF THE FRONT N OF 24N. A 1022 MB HIGH PRES LOCATED NEAR 31N75W IS BEHIND THE FRONT PRODUCING MOSTLY FAIR WEATHER ACROSS THE BAHAMAS. THIS HIGH IS FORECAST TO MOVE ESE OVER THE W ATLC DURING THE NEXT 24 HOURS. THE REMAINDER OF THE CENTRAL AND E ATLC IS DOMINATED BY A 1024 MB SFC HIGH LOCATED NEAR 33N40W. THE TIGHT PRES PATTERN BETWEEN THE HIGH AND THE AFOREMENTIONED FRONT IS PRODUCING SLY WINDS OF 20-30 KT WITHIN 300 NM E OF THE COLD FRONT N OF 23N. IN THE UPPER LEVELS...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES DE DISCUSSION AREA. IN THE DEEP TROPICS...AN ELONGATED RIDGE REMAINS BETWEEN AFRICA AND THE WINDWARD ISLANDS ENHANCING CONVECTION ALONG THE ITCZ. $$ GR