000 AXNT20 KNHC 262357 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU APR 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 2N25W 3N40W EQ50W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2N-6N BETWEEN 11W-16W... AND WITHIN 80 NM N OF THE AXIS BETWEEN 24W-28W. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION ARE ALONG THE NE BRAZILIAN COAST...AS WELL AS OVER SW AFRICA. ...DISCUSSION... GULF OF MEXICO... AS OF 21Z...A WEAK COLD FRONT EXTENDS FROM MOBILE ALABAMA TO 25N92W WHERE IT BEGINS TO DISSIPATE. A SQUALL LINE IS AHEAD OF THE FRONT MOVING ACROSS THE FLORIDA PANHANDLE. MOSAIC DOPPLER RADAR FROM THE SE IS SHOWING A NARROW LINE OF STRONG TSTMS ALONG 31N85W 29N87W. SOME CONVECTIVE ACTIVITY IS ALSO FIRING UP OVER THE NE QUADRANT OF THE GULF. THE FRONT IS FORECAST TO STEADILY WEAKEN AND DISSIPATE IN THE NEXT 24-48 HOURS. MODERATE SLY RETURN FLOW IS AHEAD OF THE FRONT SHIFTING TO THE NE WITH THE FRONTAL PASSAGE. ALOFT...A SHARP UPPER LEVEL TROUGH IS MOVING EWD ACROSS THE EASTERN GULF EXTENDING SOUTH ACROSS THE YUCATAN PENINSULA AND GUATEMALA INTO THE EPAC. STRONG SWLY WINDS AHEAD OF THE TROUGH ARE TRANSPORTING UPPER LEVEL MOISTURE/HIGH CLOUDS ACROSS CENTRAL AMERICA INTO THE WESTERN CARIBBEAN. STRONG SUBSIDENCE AND DRY AIR DOMINATES THE WEST GULF. CARIBBEAN... A SHARP UPPER LEVEL TROUGH IS ENTERING THE NW CARIBBEAN WHILE AN UPPER RIDGE...ANCHORED ON A HIGH OVER VENEZUELA DOMINATES THE REMAINDER OF THE BASIN. SWLY WINDS BETWEEN THE TROUGH AND THE RIDGE ARE SUPPORTING CONVECTIVE ACTIVITY ACROSS CENTRAL AMERICA...FROM PANAMA TO BELIZE. THESE WINDS ARE ALSO ADVECTING UPPER LEVEL MOISTURE/HIGH CLOUDS ACROSS CENTRAL AMERICA INTO THE WESTERN CARIBBEAN/CUBA. THE BASE OF AN ATLC UPPER TROUGH CLIPS PUERTO RICO AND THE VIRGIN/LEEWARD ISLANDS ENHANCING THE SHOWER ACTIVITY OVER THE NE CARIBBEAN. A JET STREAM BRANCH WITH CORE WINDS OF 70 TO 90 KT EXTENDS NE AND THEN E FROM THE BASE OF THIS TROUGH ACROSS THE ATLC TO W AFRICA...CROSSING JUST NORTH OF THE CANARY ISLANDS. THIN HIGH CLOUDS ARE ASSOCIATED WITH THE JET. A SFC TROUGH...REMNANTS OF THE STATIONARY FRONT THAT PREVIOUSLY AFFECTED PUERTO RICO AND THE VIRGIN ISLANDS IS ANALYZED ON THE 18Z MAP OVER THE SAME ISLANDS. CLUSTERS OF MODERATE TO STRONG CONVECTION HAVE DEVELOPED OVER NORTHERN COLOMBIA EARLY THIS EVENING AND ARE BEING AIDED BY THE TYPICAL HEAT LOW THAT USUALLY RESIDES IN THIS AREA. HIGH PRES N OF THE AREA IS GENERATING MODERATE TO STRONG EASTERLY TRADE WINDS ACROSS THE ENTIRE CARIBBEAN. ATLANTIC... A BROAD DEEP LAYERED TROUGH COVERS THE CENTRAL ATLC WITH THE ASSOCIATED STATIONARY FRONT EXTENDING SOUTHWESTWARD FROM 31N36W TO 26N51W. FROM THERE...A SFC TROUGH EXTENDS TO THE VIRGIN ISLANDS. BROKEN LOW/MID CLOUDS ARE RELATED TO THE FRONT/TROUGH. AT THE SURFACE...A RIDGE IS BEHIND THE FRONT COVERING THE W ATLC THE BAHAMAS...CUBA AND THE STATE OF FLORIDA ANCHORED BY A 1024 MB HIGH LOCATED SE OF BERMUDAS NEAR 31N60W. ANOTHER 1024 MB HIGH LOCATED WELL N OF THE AREA EXTENDS A RIDGE OVER THE E-CENTRAL ATLC. PATCHES OF LOW LEVEL CLOUDS ARE SEEN ACROSS THE ATLC UNDER THE INFLUENCE OF THIS RIDGE SOME OF WHICH ARE NOW MOVING INTO THE EASTERN CARIBBEAN THROUGH THE LESSER ANTILLES. ALOFT... AN UPPER LOW REMAINS IN THE E TROPICAL ATLC SW OF THE CAPE VERDE ISLANDS NEAR 12N37W. $$ GR