000 AXNT20 KNHC 122357 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAY 12 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... TROPICAL WAVE IS ALONG 53W/54W S OF 10N MOVING W 10-15 KT. THE WAVE COUPLED WITH THE ITCZ IS ENHANCING CONVECTION OVER THE GUYANAS REGION. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM EQUATOR TO 7N BETWEEN 51W AND 58W. AN EARLIER QUIKSCAT PASS SHOWED LOW-LEVEL NE FLOW OF 15 TO 20 KT ACROSS THIS AREA. THE GFS MODEL HAS MOISTURE FROM THIS TROPICAL WAVE SPREADING OVER THE SOUTHERN WINDWARD ISLANDS ON WED. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 2N25W 3N45W 4N51W. A CLUSTER OF MODERATE TO STRONG CONVECTION IS NEAR 4N15W. SCATTERED MODERATE CONVECTION IS WITHIN 300 NM N OF AXIS BETWEEN 39W AND 45W. ...DISCUSSION... GULF OF MEXICO... A STRONG EXTRATROPICAL CYCLONE IS JUST OFFSHORE THE MID-ATLANTIC STATES MOVING SE ACROSS THE OCEAN. AS OF 2100 UTC...THE ASSOCIATED COLD FRONT ENTERS THE FORECAST AREA NEAR 31N73W THEN CONTINUES SW ACROSS SOUTH FLORIDA AND THE EASTERN GULF TO NEAR 25N87W. AT THIS POINT...THE FRONT BECOMES STATIONARY AND EXTENDS ALONG 26N90W 27N97W. UNUSUAL MODERATE TO STRONG WLY WINDS WERE BLOWING AHEAD OF THE FRONT OVER SOUTH FLORIDA DURING THE WEEKEND BUT PARTICULARLY ON SUN...ALLOWING TEMPERATURES TO CLIMB INTO THE MID 90S. LATEST VIS IMAGERY FOR THE DAY SHOW A VERY WELL DEFINED ROPE CLOUD LINE AND EMBEDDED ISOLATED SHOWERS ASSOCIATED WITH THE FRONTAL BOUNDARY. HIGH PRES WITH A COOLER AND MUCH DRIER AIR MASS IS BUILDING INTO THE AREA BEHIND THE FRONT. NLY WINDS OF 15-20 KT FOLLOW THE FRONTAL SYSTEM IN THE E PORTION OF THE GULF. THIS FRONT IS EXPECTED TO REACH WEST-CENTRAL CUBA LATE TUE MORNING. ALOFT...A MID/UPPER RIDGE ANCHORED ON A HIGH OVER THE GULF OF HONDURAS DOMINATES THE ENTIRE GULF REGION. SWLY UPPER LEVEL WINDS ON THE WESTERN SIDE OF THE RIDGE ARE ENHANCING CONVECTION ACROSS NORTH-CENTRAL MEXICO. CARIBBEAN SEA... A MID TO UPPER HIGH CENTERED OVER THE GULF OF HONDURAS EXTENDS A RIDGE OVER THE WEST AND CENTRAL CARIBBEAN WHILE UPPER TROUGHING RUNS FROM THE NRN LEEWARD ISLANDS TO THE N COAST OF COLOMBIA. MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY/STABLE AIR MASS IS WITHIN THE RIDGE SUPPRESSING THE DEVELOPMENT OF ANY SIGNIFICANT CONVECTION. AT THE SURFACE...HIGH PRES OVER THE EASTERN ATLANTIC NEAR 29N31W EXTENDS A RIDGE TO THE EASTERN CARIBBEAN INCLUDING PUERTO RICO AND THE VIRGIN ISLANDS. THIS RIDGE IS GIVING THE AREA MOSTLY FAIR WEATHER AND A PREVAILING SOUTHEAST WIND FLOW. MODERATE TRADE WINDS OF 15 TO 20 KT ARE FOUND OVER THE CENTRAL CARIBBEAN MAINLY JUST OFFSHORE THE COLOMBIAN COAST WITH LIGHT TO MODERATE E TO SE WINDS ELSEWHERE. ACCORDING TO THE COMPUTER MODEL...THE TROPICAL WAVE CURRENTLY ALONG 53W/54W WILL PROBABLY BRING SOME MOISTURE TO THE SRN WINDWARD ISLANDS ON WED. ATLANTIC OCEAN... THE LARGE EXTRATROPICAL CYCLONE THAT HAS BEEN PRODUCING COLD AND RAINY CONDITIONS AS WELL AS STRONG WINDS OVER THE NE OF U.S. AND THE MID ATLC STATE IS FINALLY MOVING AWAY FROM THE AREA. AS A RESULT...COASTAL WINDS ARE FORECAST TO STEADILY DIMINISH TONIGHT THROUGH TUE. THE ATTENDANT COLD FRONT ENTERS THE FORECAST AREA NEAR 31N73W THEN CONTINUES SW ACROSS SOUTH FLORIDA AND THE EASTERN GULF. A BAND OF SHOWERS AND ISOLATED TSTMS IS AHEAD OF THE FRONT AFFECTING THE AREA N OF 27N BETWEEN 60W AND 70W. A DIFFLUENT PATTERN ALOFT...BETWEEN THE UPPER TROUGH THAT SUPPORTS THE FRONT AND AN UPPER-LEVEL RIDGE OVER THE CENTRAL ATLC IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. THE REMAINDER OF THE DISCUSSION AREA IS UNDER THE INFLUENCE OF A 1025 MB SFC HIGH PRES SYSTEM CENTERED NEAR 29N31W. BROAD MID TO UPPER RIDGE COVERS THE DEEP TROPICS. THIS UPPER FEATURE IS ENHANCING CONVECTION ALONG THE ITCZ WEST OF 38W. $$ GR.