000 AXNT20 KNHC 122343 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU APR 12 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. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 1N20W CROSSING THE EQUATOR BETWEEN 30W-40W INTO NE BRAZIL NEAR 2N47W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE WITHIN 100 NM N OF THE AXIS E OF 33W. SIMILAR CONVECTION IS OVER SW AFRICA AND NE BRAZIL. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT EXTENDS FROM THE WEST ATLC ACROSS N-CENTRAL FLORIDA AND THE CENTRAL GULF OF MEXICO TO THE DEEP SOUTH...WHERE IT BECOMES STATIONARY. THE COLD FRONT IS GENERALLY MARKED BY A CHANGE IN DEW POINT AND NARROW LINES OF LOW LEVEL CLOUDS. MOST OF THE CONVECTIVE ACTIVITY IS ASSOCIATED WITH THE PRE-FRONTAL TROUGH THAT CROSSED SOUTH FLORIDA THIS MORNING GENERATING STRONG SHOWERS/TSTMS WITH GUSTY WINDS OF AROUND 50 KT. AS OF 21Z...THE PRE-FRONTAL TROUGH RUNS FROM THE NW BAHAMAS TO WEST-CENTRAL CUBA. ONCE AGAIN...THE KEY WEST DOPPLER RADAR SHOWS RAINFALL AMOUNTS OF 2-3 INCHES (50-75 MM) IN SOME SPOTS OVER CUBA AND THE STRAIT OF FLORIDA. THE FRONT IS FORECAST TO RAPIDLY DISSIPATE AS IT CONTINUES TO MOVES SE. VERY DRY AIR FOLLOWS THIS COLD FRONT COVERING THE SE US AND THE N GULF WATERS N OF 25N. SELY RETURN FLOW IS EXPECTED TO INCREASE IN ADVANCE OF A SECOND COLD FRONT FORECAST TO ENTER THE GULF ON SATURDAY. WINDS AND SEAS WILL ALSO BE STRONGER BEHIND THE FRONT. ALOFT...W TO SW UPPER FLOW DOMINATES THE GULF WITH UPPER DIFFLUENCE ENHANCING THE CONVECTION OVER CUBA AND THE BAHAMAS. CARIBBEAN SEA... BROAD UPPER LEVEL RIDGE COVERS THE CARIBBEAN AND CENTRAL AMERICA ANCHORED BY AN UPPER HIGH CENTERED MIDWAY BETWEEN JAMAICA AND COSTA RICA. UPPER LEVEL MOISTURE IS BEING TRANSPORTED FROM THE E PACIFIC OVER CENTRAL AMERICA AND THE W CARIBBEAN BY THE SWLY FLOW AROUND THE RIDGE. UPPER DIFFLUENCE ON THE WEST SIDE OF THIS ANTICYCLONE AND THE CLOSE PROXIMITY OF THE EPAC ITCZ ARE SUPPORTING THE DEVELOPMENT OF CLUSTERS OF MODERATE CONVECTION FROM PANAMA/COSTA RICA TO HONDURAS. DRY MID TO UPPER AIR AND MOSTLY FAIR WEATHER DOMINATE MUCH OF THE REMAINDER OF THE REGION. SFC HIGH PRESSURE NE OF THE AREA IS PRODUCING MODERATE E/NE WINDS IN THE E AND CENTRAL ATLC...THAT VEER MORE SE IN THE NW PORTION AROUND THE SW PORTION OF THE RIDGE. HI PRES WILL BUILD MORE N OF THE AREA INTO FRI...ALLOWING FOR A MORE TYPICAL MODERATE TO FRESH TRADE REGIME TO TAKE OVER MUCH OF THE BASIN TOMORROW. ATLANTIC OCEAN... AS OF 21Z...A COLD FRONT ENTERS THE FORECAST AREA NEAR 32N75W THEN CONTINUES SW AND MAINLY W OVER N-CENTRAL FLORIDA AND THE GULF OF MEXICO. NUMEROUS SHOWERS/THUNDERSTORMS ARE MOVING ACROSS THE BAHAMAS AND WEST-CENTRAL CUBA ASSOCIATED WITH THE AFOREMENTIONED PRE-FRONTAL TROUGH. A BROAD UPPER RIDGE FROM THE CARIBBEAN ALSO EXTENDS ACROSS THE WEST ATLC. A DEEP LAYERED TROUGH OVER THE N/CENTRAL ATLC N OF THE REGION IS DRAPING A FRONTAL BOUNDARY INTO THE AREA ALONG 32N40W 28N50W TO A 1011 MB SFC LOW LOCATED NEAR 30N65W. THE FRONT COMBINED WITH UPPER LEVEL DIFFLUENCE IS CREATING A BAND OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS N OF 26N BETWEEN 40W AND THE 1011MB LOW. A SURFACE RIDGE COVERS THE REMAINDER OF THE E-CENTRAL ATLC WITH A 1024 MB HIGH LOCATED NW OF THE MADEIRA ISLANDS NEAR 34N20W. THIS FEATURE IS PROVIDING FAIR WEATHER AND LIGHT TO MODERATE TRADES THROUGHOUT THE E ATLC. A BROAD BAND OF UPPER LEVEL MOISTURE/HIGH CLOUDS EXTENDS FROM N SOUTH AMERICA ALL THE WAY ENE TO W AFRICA CROSSING SOUTH OF THE CAPE VERDE ISLANDS. THIS UPPER LEVEL MOISTURE IS RELATED TO A TROPICAL JETSTREAM WITH CORE WINDS OF 70-90 KT. $$ GR