000 AXNT20 KNHC 241730 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE APR 24 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N10W 3N18W 5N47W 4N59W. ISOLATED MODERATE/STRONG CONVECTION FROM 3N-7N BETWEEN 9W-15W. WIDELY SCATTERED MODERATE S OF 6N BETWEEN 22W-43W. ISOLATED SHOWERS/ TSTMS FROM 5N-9N BETWEEN 48W-54W. ...DISCUSSION... GULF OF MEXICO... MAINLY FAIR CONDITIONS DOMINATE THE GULF WATERS TODAY BUT THE LEADING EDGE OF CLOUDS ASSOCIATED WITH A FRONTAL BOUNDARY OVER TEXAS IS JUST STARTING TO MOVE OFF THE COAST. THE COLD FRONT/DRYLINE IS STILL LOCATED OVER W TEXAS WITH ISOLATED TO WIDELY SCATTERED SHOWERS BREAKING OUT ACROSS E/CENTRAL TEXAS WITH SOME POTENTIALLY BRUSHING THROUGH THE COASTAL WATERS. AN UPPER RIDGE AXIS LIES FROM THE BAY OF CAMPECHE TO THE SE U.S. WITH THE E HALF OF THE GULF AND FLORIDA DOMINATED BY MODERATE/STRONG SUBSIDENCE...AND INCREASING UPPER LEVEL MOISTURE OVER THE W PART STREAMING ACROSS NE MEXICO. THE COLD FRONT IS EXPECTED TO EASE ITS WAY TO THE COAST BY WED NIGHT/EARLY THU BUT THEN STALL DUE TO LACK OF UPPER SUPPORT. THIS SCENARIO WOULD THEN ONLY SUPPORT SCATTERED SHOWERS/TSTMS OVER THE FAR NRN GULF WED THROUGH FRI AS THE MAIN ENERGY ASSOCIATED WITH THE FRONT SKIRTS BY TO THE N. CARIBBEAN... AN UPPER LEVEL TROUGH LOCATED OVER THE W/CENTRAL ATLC DRAPES SW INTO THE W CARIBBEAN FROM THE WINDWARD PASSAGE SW TO NICARAGUA AND HONDURAS. STRONG CONFLUENCE INTO THE TROUGH AXIS IS PRODUCING MODERATE TO VERY STRONG SUBSIDENCE OVER THE W CARIBBEAN...FOCUSED MOST STRONGLY FROM E CUBA TO THE CAYMAN ISLANDS. TO THE E...BROAD SW FLOW ALOFT LIES AHEAD OF THE TROUGH AND IS PULLING SLIGHTLY MORE MOIST AIR UP FROM SOUTH AMERICA. THE PATTERN IS SOMEWHAT DECEIVING DUE TO A MOIST LOW-LEVEL ENVIRONMENT AND A WEAKENING SURFACE TROUGH EXTENDING FROM NEAR ANGUILLA AND THE BRITISH VIRGIN ISLANDS SW TO 15N74W. WIDELY SCATTERED SHOWERS LIE TO THE N OF THE TROUGH...SOME OF WHICH ARE MOVING E TO W ACROSS PUERTO RICO AND THE VIRGIN ISLANDS... HISPANIOLA...AND JAMAICA. A FEW TSTMS ARE ALSO LOCATED OVER THE WATERS NEAR THE COLOMBIA/PANAMA JUNCTURE WWD TO THE PANAMA CANAL...PARTLY AIDED BY OUTFLOW ALOFT. SE OF THE TROUGH...DRIER LOW-LEVEL AIR AND SUBSIDENCE IN THE MID/UPPER LEVELS IS PRODUCING A MAINLY CLEAR DAY ACROSS THE SRN LEEWARD AND WINDWARD ISLANDS AS WELL AS ACROSS THE VENEZUELA COAST. ATLANTIC... A 1028 MB HIGH IS CENTERED OVER THE W ATLC NEAR 31N74W WITH A RIDGE ALIGNED FROM BERMUDA TO N FLORIDA. AN UPPER LEVEL TROUGH IS LOCATED OVER THE SAME AREA WITH THE AXIS FROM 31N63W TO THE WINDWARD PASSAGE...AND THIS IS PRODUCING MAINLY DRY CONDITIONS AT ALL LEVELS OF THE ATMOSPHERE. ONLY A FEW VERY ISOLATED SHOWERS ARE NOTED IN THE TRADES JUST TO THE E OF THE BAHAMAS. FARTHER E...THE UPPER TROUGH AND AN ASSOCIATED UPPER LOW NEAR 33N54W HAVE SUPPORTED THE DEVELOPMENT OF A WEAK 1020 MB LOW NEAR 30N52W ALONG THE FRONTAL BOUNDARY WHICH HAS BEEN OVER THE CENTRAL ATLC FOR A FEW DAYS. A STATIONARY FRONT STILL EXTENDS SW OF THE LOW TO THE NRN LEEWARD ISLANDS WITH WIDELY SCATTERED SHOWERS UP TO 180 NM OF THE BOUNDARY. TO THE E OF THE LOW...THE FRONT HAS MOVED N AS A WARM FRONT TO 30N48W 28N43W THEN CONNECTED TO A STATIONARY FRONT TO 31N27W. OVER THE E ATLC...A STRONG MID-LEVEL HIGH IS CENTERED NEAR 20N40W WHICH IS KEEPING MOST OF THE HIGH CLOUDINESS STREAMING N OF THE AREA TOWARDS THE AZORES...AND MODERATE/STRONG SUBSIDENCE SWD TO 6N. THE DEVELOPMENT OF THIS SUBSIDENCE IS BEING AIDED BY AN UPPER LOW IN THE TROPICS NEAR 10N27W...WHICH SEPARATES DRY AIR TO THE NW WITH A DEEP TROPICAL MOISTURE PLUME TO THE E AND SE. THE ITCZ HAS COME CONVECTION NEAR ITS AXIS TODAY...BUT NONE OF IT IS REALLY ALL THAT FOCUSED AS IT HAD BEEN IN PREVIOUS DAYS. $$ BERG