000 AXNT20 KNHC 132344 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN APR 13 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. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 6N11W 3N24W THEN ALONG THE EQUATOR BETWEEN 35W AND 50W INTO NE BRAZIL. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE INLAND OVER GUINEA...SIERRA LEONE AND LIBERIA. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N OF AXIS BETWEEN 20W AND 25W...AND WITHIN 180 NM S OF AXIS BETWEEN 30W AND 36W. ...DISCUSSION... THE GULF OF MEXICO... A RATHER STRONG COLD FRONT FOR THIS TIME OF THE YEAR CONTINUES TO MOVE ACROSS SOUTH FLORIDA AND THE SE PORTION OF THE GULF EARLY THIS EVENING. AS OF 2100 UTC...THE FRONTAL BOUNDARY STRETCHES FROM SOUTH FLORIDA...JUST SOUTH OF LAKE OKEECHOBEE TO 22N89W WHERE IT BECOMES STATIONARY THEN CONTINUES SW INTO THE EASTERN PART OF THE BAY OF CAMPECHE. A BROKEN BAND OF LOW/MID CLOUDS WITH EMBEDDED SHOWERS IS ASSOCIATED WITH THE FRONT. COLD AIR HAS PENETRATED INTO THE SIERRA MADRE MOUNTAINS AS DEPICTED BY A RATHER UNIFORM STRATUS CLOUDS COVER AND A STATIONARY FRONT IS ALSO ANALYZED OVER CENTRAL MEXICO. MOSAIC DOPPLER RADAR FROM THE SE U.S. INDICATES A BAND OF SHOWERS AND ISOLATED TSTMS NEAR THE LAKE OKEECHOBEE REGION WITH STRONGER SHOWERS AND TSTMS OFFSHORE WEST PALM BEACH. A COOLER AND DRIER ATMOSPHERE IS IN THE WAKE OF THE FRONT WITH DEWPOINTS IN THE 40S AND FAIR SKIES OVER THE NORTHERN GULF WATERS. A SECONDARY PUSH OF COOLER AIR...DEPICTED ON THE SFC ANALYSIS AS A TROUGH OVER THE SE CONUS IS EXPECTED TO MOVE THROUGH THE GULF TONIGHT REACHING SOUTH FLORIDA MONDAY NIGHT. NLY WINDS OF 20 TO 25 KT WILL FOLLOW THE SECONDARY FRONT. GALE FORCE WINDS ARE BLOWING BEHIND THE MAIN FRONT OVER THE SW GULF...BUT ARE EXPECTED TO DIMINISH DURING THE NEXT 6-12 HOURS. A DEEP-LAYERED TROUGH EXTENDING OVER THE EASTERN U.S. SUPPORTS THE ABOVE MENTIONED COLD FRONT. MOSTLY ZONAL FLOW DOMINATES THE ENTIRE GULF. A 110-130 KT JETSTREAM IS OVER THE N GULF STATES. EXPECT THE COLD FRONT TO MOVE SOUTH OF AREA TONIGHT. THE CARIBBEAN SEA... STRONG SUBSIDENCE AND IMPLIED DRY STABLE CONDITIONS ALOFT REMAIN IN CONTROL OF THE WEATHER PATTER ACROSS MOST OF THE CARIBBEAN SEA THIS EVENING. AS USUAL...SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW IS PRODUCING ISOLATED TO SCATTERED SHOWERS ACROSS THE BASIN EXCEPT FOR THE LESSER ANTILLES...MAINLY SOUTH OF GUADALOUPE WHERE THE COMBINATION OF SFC TROUGH AND A DIFFLUENT PATTERN ALOFT IS HELPING TO PRODUCE MULTILAYERED CLOUDS WITH SCATTERED TO NUMEROUS SHOWERS...HEAVY AT TIMES. CONVECTION HAS ALSO DEVELOPED OVER EASTERN VENEZUELA. THE GFS COMPUTER MODEL HAS MOISTURE ASSOCIATED WITH THIS SFC TROUGH AFFECTING THE EASTERN CARIBBEAN...INCLUDING THE US/UK VIRGIN ISLANDS AND PUERTO RICO DURING THE NEXT 24 HOURS. FRESH TRADEWINDS ARE OVER THE CARIBBEAN SEA. AN ASCAT PASS SHOWED NELY WINDS OF 20 TO 25 KT NEAR THE COLOMBIAN COAST. THE COLD FRONT CURRENTLY MOVING OVER THE SE GULF AND SOUTH FLORIDA WILL ENTER THE NW CARIBBEAN TONIGHT AND IS FORECAST TO STALL FROM EASTERN CUBA TO THE GULF OF HONDURAS MON NIGHT. THE ATLANTIC OCEAN... THE PREVIOUSLY MENTIONED COLD FRONT ENTERS THE FORECAST AREA NEAR 31N75W THE CONTINUES SW THROUGH SOUTH FLORIDA AND THE GULF OF MEXICO. A BAND OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS IS RELATED TO THE FRONT OVER THE W ATLC. THIS FRONTAL SYSTEM WILL MOVE ACROSS THE CENTRAL BAHAMAS MONDAY MORNING REACHING THE SE BAHAMAS MONDAY EVENING. E OF FRONT...A 1023 MB HIGH IS NEAR 28N48W COVERING THE REMAINDER OF THE W ATLC AND THE THE CENTRAL ATLANTIC. THE TAIL END OF A COLD FRONT IS OVER THE E ATLANTIC ALONG 31N28W 28N31W 25N35W. SCATTERED SHOWERS ARE ASSOCIATED WITH THE FRONT. A RIDGE ANCHORED ON A HIGH NEAR PORTUGAL DOMINATES THE REMAINDER OF THE FORECAST AREA. ALOFT... A RIDGE/TROUGH/RIDGE PATTERN COVERS THE DISCUSSION AREA. A RIDGE IS OVER THE W ATLANTIC W OF 50W. AN ELONGATED UPPER TROUGH EXTENDS FROM THE E ATLC NEAR 31N20W ALL THE WAY WSW TO THE NE CARIBBEAN. WLY UPPER FLOW DOMINATES THE AREA BETWEEN AFRICA AND THE LESSER ANTILLES FROM 12N TO 20N. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE TROPICAL ATLANTIC NEAR 8N40W. $$ GR