000 AXNT20 KNHC 161744 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON FEB 16 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 4N8W 2N20W 1N30W CROSSING THE EQUATOR AT 37W...AND INTO NE BRAZIL NEAR 2S47W WHERE SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FIRED UP. ELSEWHERE... ISOLATED MODERATE CONVECTION IS WITHIN 100 NM EITHER SIDE OF AXIS BETWEEN 8W AND 15W. SIMILAR CONVECTION IS WITHIN 130 NM N OF AXIS BETWEEN 20W AND 24W...AND BETWEEN 30W AND 40W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A COLD FRONT ENTERS THE GULF OF MEXICO THROUGH THE STRAITS OF FLORIDA THEN CONTINUES MAINLY WEST TO NEAR 23N86W WHERE IT BEGINS TO DISSIPATE. VIS SATELLITE IMAGERY SHOWS A ROPE CLOUD AT THE LEADING EDGE OF THE FRONT...WHILE DOPPLER RADAR REVEALS ISOLATED SHOWERS BETWEEN THE FLORIDA KEYS AND THE COAST OF CUBA. HIGH PRESSURE CURRENTLY OVER THE CENTRAL CONUS IS INVADING THE NORTHERN GULF WATERS PRODUCING N TO NE WINDS OF 15 TO 20 KT. THESE WINDS ARE USHERING IN A RELATIVELY COOLER AND DRIER AIR MASS. COLD AIR STRATOCUMULUS CLOUDS ARE BEHIND THE FRONT WHICH IS EXPECTED TO MOVE S OF THE AREA EARLY THIS AFTERNOON. THE FRESH NE WINDS WILL VEER MORE SE TO S TONIGHT AS THE HIGH PRES SHIFTS EAST OVER THE EASTERN U.S. SOUTHERLY RETURN FLOW IS FORECAST TO DEVELOP OFF THE TEXAS COAST ON TUE. IN THE UPPER LEVELS...A RIDGE...ANCHORED ON A HIGH OVER THE EPAC NEAR 11N97W...DOMINATES THE ENTIRE GULF PRODUCING STRONG NW FLOW AND ALSO STRONG SUBSIDENCE S OF 26N INCLUDING SE MEXICO AND THE YUCATAN PENINSULA. A 130-150 KT UPPER LEVEL JET IS INLAND OVER THE NORTH GULF STATES. 90-110 KT UPPER LEVEL WINDS ARE OVER THE N GULF N OF 26N. CARIBBEAN SEA... MAIN WEATHER FEATURE ACROSS THE BASIN EARLY THIS AFTERNOON IS THE SURFACE TROUGH PRESENTLY AFFECTING THE WINDWARD ISLANDS AND THE FAR SE CARIBBEAN. THE TROUGH AXIS EXTENDS FROM MARTINIQUE TO NE VENEZUELA NEAR 8N63W. TRINIDAD REPORTED 1.39 INCHES OF RAIN FOR THE PAST 24 HOURS ENDING THIS MORNING AT 7 AM. SFC DATA AND A RECENT QSCAT PASS CLEARLY INDICATE THE WIND SHIFT ASSOCIATED WITH THE TROUGH. IN ADDITION...THE CLOUD PATTERN IS EXHIBITING SOME CYCLONIC TURNING. THE MOISTURE THAT ACCOMPANIES THIS TROUGH WILL CONTINUE TO AFFECT THE SE CARIBBEAN SPREADING OVER THE ABC ISLANDS LATER TODAY INTO TUE. ON THE OTHER HAND...THE COLD FRONT CURRENTLY OVER THE STRAITS OF FLORIDA AND THE SOUTHERN GULF OF MEXICO WILL MOVE ACROSS WESTERN CUBA THIS AFTERNOON FOLLOWED BY MODERATE NLY WINDS...THEN THE FRONT WILL MOVE QUICKLY EWD REACHING THE WINDWARD PASSAGE BY TUE MORNING AND AFFECTING HISPANIOLA TUE AFTERNOON. THE FRONT IS FORECAST BY THE COMPUTER MODELS TO MOVE ACROSS PUERTO RICO AND THE VIRGIN ISLANDS TUE EVENING INTO WED. IN THE MEAN TIME...PATCHES OF LOW LEVEL MOISTURE CARRIED BY THE TRADE WINDS ARE NOTED OVER THE CENTRAL AND WESTERN CARIBBEAN...MORE CONCENTRATED IN A BAND EXTENDING FROM E CUBA TO THE GULF OF HONDURAS. MODERATE TO FRESH TRADE WINDS ARE BLOWING ACROSS THE REGION WITH THE STRONGEST WINDS OF UP TO 25 KT NEAR THE COAST OF COLOMBIA. IN THE UPPER LEVELS... A RIDGE/TROUGH/RIDGE PATTERN COVERS THE AREA WITH STRONG SUBSIDENCE OVER THE WEST AND CENTRAL CARIBBEAN. ATLANTIC OCEAN... A GALE CENTER IS TAKING SHAPE OVER THE W ATLC NEAR 31.5N71W. THE TRAILING COLD FRONT EXTENDS SW ACROSS THE NW BAHAMAS AND THE STRAITS OF FLORIDA INTO THE GULF OF MEXICO. THE FRONT IS FORECAST TO QUICKLY MOVE EWD AS THE EXTRATROPICAL LOW RAPIDLY INTENSIFIES BECOMING A 1001 MB GALE CENTER NEAR BERMUDA THIS EVENING. THIS LOW PRES CENTER WILL CONTINUE TO DEEPEN TO A 998 MB STORM CENTER IN ABOUT 24 HOURS...LIKELY REACHING NEAR HURRICANE FORCE WINDS OVER THE CENTRAL ATLC TUE AFTERNOON. TIGHT PRES GRADIENT BETWEEN THIS EXTRATROPICAL CYCLONE AND HIGH PRES OVER THE EASTERN CONUS WILL PRODUCE A LARGE AREA OF FRESH TO STRONG WINDS N OF 25N BETWEEN 47W-67W. THE REMAINDER OF THE ATLANTIC DISCUSSION AREA IS UNDER THE INFLUENCE OF A RIDGE ANCHORED BY A 1023 MB HIGH LOCATED NEAR 27N34W. THIS SYSTEM IS GENERATING MOSTLY FAIR WEATHER...AND A WIDESPREAD SWATH OF 20 TO 25 KT OVER THE TROPICS...PARTICULARLY BETWEEN 35W AND 55W. STRONG WLY FLOW ALOFT IS NOTED OVER THE N SECTION OF THE W AND CENTRAL ATLC DUE TO THE PRESENCE OF A JET-STREAM WHICH ALSO CROSSES THE N GULF STATES. AN UPPER-LEVEL TROUGH RUNS FROM THE MADEIRA ISLANDS TO THE CAPE VERDE ISLANDS. A JET-STREAM BRANCH WITH CORE WINDS OF 90-110 KT IS AROUND THE BASE OF THIS TROUGH CROSSING OVER AND JUST SOUTH THE CAPE VERDE ISLANDS...AND ENTERING W AFRICA THROUGH SENEGAL. $$ GR