000 AXNT20 KNHC 121750 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... ITCZ AXIS EXTENDS IS CENTERED ALONG 7N9W 3N20W 2N34W 1N48W. CLUSTERS OF MODERATE/STRONG CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE AXIS BETWEEN 18W-35W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM OF THE AXIS W OF 41W AND INTO SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT EXTENDS FROM THE WEST ATLC ACROSS THE FLORIDA PANHANDLE THROUGH THE N/CENTRAL GULF AND CONNECTS TO A STATIONARY FRONT IN THE WEST GULF NEAR 26N94W. THE STATIONARY FRONT CONTINUES WEST THROUGH THE TEXAS/MEXICO BORDER THEN EXTENDS NORTH WELL INLAND OVER S TEXAS AND NEW MEXICO. A PREFRONTAL TROUGH EXTENDING FROM CENTRAL FLORIDA TO NEAR 24N86W IS GENERATING NUMEROUS SHOWERS/THUNDERSTORMS ACROSS SOUTH FLORIDA AND THE STRAITS OF FLORIDA. THE COLD FRONT IS GENERALLY MARKED BY A CHANGE IN DEW POINT WITH THE CONVECTION CONSTRAINED TO THE NEAR PREFRONTAL THROUGH. THE FRONT IS EXPECTED TO STALL FROM FLORIDA BIG BEND TO NW BAY OF CAMPECHE LATE THIS AFTERNOON AND RAPIDLY DISSIPATE. LIGHT TO MODERATE WINDS ARE EXPECTED TO INCREASE IN ADVANCE OF A SECOND COLD FRONT FORECAST TO ENTER THE GULF FRIDAY. ALOFT...WIDE SPREAD W TO SW UPPER FLOW DOMINATES THE GULF WITH UPPER DIFFLUENCE ENHANCING THE CONVECTION OVER S FLORIDA. OTHERWISE...MODERATE SUBSIDENCE AND DRY AIR COVER THE REMAINDER OF THE GULF. CARIBBEAN SEA... BROAD UPPER LEVEL RIDGE COVERS THE CARIBBEAN ANCHORED BY AN UPPER HIGH CENTERED OVER THE SW CARIBBEAN NEAR 14N78W. UPPER LEVEL MOISTURE IS BEING TRANSPORTED FROM THE E PACIFIC OVER THE W CARIBBEAN BY THE SWLY FLOW AROUND THE RIDGE. DRY MID TO UPPER AIR AND MOSTLY FAIR WEATHER DOMINATE MUCH OF THE REMAINDER OF THE CARIBBEAN. A SMALL CLUSTER OF MODERATE CONVECTION LIKELY TIED TO THE EPAC EXTENSION OF THE ITCZ IS NOTED IN THE SW CARIBBEAN NEAR 10N82W. 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... A COLD FRONT EXTENDS FROM A LOW WELL NORTH OF THE AREA HUGGING THE EAST COAST OF THE US AND CROSSING THE FLORIDA PANHANDLE INTO THE GULF OF MEXICO. NUMEROUS SHOWERS/THUNDERSTORMS ARE MOVING INTO THE WEST ATLC FROM S FLORIDA AHEAD OF THE PREFRONTAL TROUGH THAT EXTENDS FROM CENTRAL FLORIDA IN THE GULF. A BROAD UPPER RIDGE FROM THE CARIBBEAN ALSO EXTENDS ACROSS THE W ATLC INTO THE S/CENTRAL ATLC. A DEEP LAYERED TROUGH OVER THE N/CENTRAL ATLC N OF THE REGION IS DRAPING A COLD FRONT INTO THE AREA ALONG 32N40W TO 27N56W THEN NW TO A 1012 MB LOW NEAR 30N65W. THE FRONT COMBINED WITH UPPER LEVEL DIFFLUENCE IS CREATING OVERCAST SKIES WITH POSSIBLE SHOWERS N OF 26N BETWEEN 40W AND THE 1012MB LOW. A SURFACE RIDGE COVERS THE ATLC E OF THE CENTRAL ATLC COLD FRONT ANCHORED BY A 1025 MB HIGH NEAR 34N20W AND EXTENDS S INTO THE TROPICS PROVIDING FAIR WEATHER AND LIGHT TO MODERATE TRADES THROUGHOUT THE E ATLC. $$ MW/RJW