000 AXNT20 KNHC 201052 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU MAR 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...THE ITCZ... FROM THE LIBERIA COAST NEAR 6N10W TO 4N20W 1N30W...IN BETWEEN THE EQUATOR AND 1N BETWEEN 30W AND 38W...CROSSING THE EQUATOR AT 39W...AND GOING INTO NORTHEASTERN BRAZIL NEAR 4S47W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS SOUTH OF 6N BETWEEN AFRICA AND 46W. ...DISCUSSION... THE GULF OF MEXICO... UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS THE AREA...AS A COLD FRONT MOVES EASTWARD THROUGH THE AREA. THE DEEP LAYER TROUGH THAT IS SUPPORTING THIS FRONT HAS MOVED NORTH OF 30N AND INTO THE NORTHEASTERN U.S.A. THE CURRENT MIDDLE TO UPPER LEVEL SOUTHWESTERLY WIND FLOW IN THE AREA IS A RESULT OF THE DISPLACEMENT OF THE TROUGH TO THE NORTHEAST OF THE AREA. THE COLD FRONT PASSES THROUGH NORTHEASTERN FLORIDA TO 25N86W...TO THE NORTH CENTRAL YUCATAN PENINSULA COAST... INTO MEXICO EAST OF THE ISTHMUS OF TEHUANTEPEC. A STATIONARY FRONT STARTS IN MEXICO JUST WEST OF THE ISTHMUS OF TEHUANTEPEC AND CONTINUES TO 21N99W. NEAR GALE-FORCE WINDS ARE BLOWING FROM THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO ACROSS THE INTERIOR OF MEXICO ALONG 94W INTO THE GULF OF TEHUANTEPEC...BECOMING GALE-FORCE ON THE EASTERN PACIFIC OCEAN SIDE OF MEXICO. THE STRONG SHOWERS AND THUNDERSTORMS FROM SIX HOURS AGO IN THE YUCATAN PENINSULA AND GUATEMALA HAVE WEAKENED WITH REMNANT CLOUDS. SHOWERS ARE POSSIBLE WITHIN 90 NM ON EITHER SIDE OF THE LINE THROUGH 31N79W TO 28N82W IN WEST CENTRAL FLORIDA...TO 25N85W IN THE GULF OF MEXICO TO THE NORTHEASTERN CORNER OF THE YUCATAN PENINSULA. THE ATLANTIC OCEAN WEST OF 54W... UPPER LEVEL ANTICYCLONIC WIND FLOW WEST OF 54W IS COURTESY OF AN ATLANTIC OCEAN RIDGE FROM EASTERN CUBA BEYOND 32N69W. THE CARIBBEAN SEA... THE TAIL END OF A WEAKENING COLD FRONT CUTS ACROSS THE EASTERN CARIBBEAN SEA ISLANDS THROUGH 14N60W TO 14N62W. COOLER AND DRIER AIR FROM THE SURFACE UPWARD INTO THE ATMOSPHERE HAS SPREAD WELL SOUTHWARD INTO THE EASTERN CARIBBEAN SEA BEHIND THIS MOST RECENT COLD FRONT. TEMPERATURES THIS MORNING AT 20/0600 UTC RANGED FROM 18 DEGREES CENTIGRADE TO 25 DEGREES CENTIGRADE BEHIND THE FRONT. DEWPOINTS RANGED FROM THE MIDDLE TEENS CENTIGRADE TO THE LOW 20'S CENTIGRADE. ANOTHER BIG STORY IS THE TREMENDOUS NORTHERLY SWELLS AFFECTING THE CARIBBEAN SEA ISLANDS FROM THE CONTINUOUS FETCH DRIVEN BY A LARGE LINGERING AND ONCE VERY POWERFUL NORTHERN ATLANTIC OCEAN LOW PRESSURE CENTER. SHOWERS ARE POSSIBLE EAST OF 70W IN CLUSTERS OF LOW CLOUDS MOVING INTO THE AREA FROM THE ATLANTIC OCEAN. THE REST OF THE CARIBBEAN SEA IS EXPERIENCING A STRONGLY SUBSIDENT MIDDLE TO UPPER LEVEL ENVIRONMENT. THE TIGHT SURFACE PRESSURE GRADIENT BETWEEN SEMI-PERMANENT LOW PRESSURE IN NORTHERN SECTIONS OF SOUTH AMERICA AND A 1024 MB ATLANTIC OCEAN HIGH NEAR 29N67W IS HELPING TO PRODUCE GALE FORCE TRADEWINDS NEAR THE COAST OF COLOMBIA. THESE CONDITIONS ARE EXPECTED TO SUBSIDE IN ABOUT 24 HOURS. THE REST OF THE ATLANTIC OCEAN EAST OF 54W... BROAD DEEP LAYER CYCLONIC WIND FLOW ACCOMPANIES THE CENTRAL ATLANTIC OCEAN TROUGH. THIS TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 31N40W TO 29N40W 20N46W 15N54W...DISSIPATING FROM 15N54W TO 14N60W AND 14N62W IN THE EASTERN CARIBBEAN SEA. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE NORTH OF 27N BETWEEN 35W AND 40W. OTHER SHOWERS ARE POSSIBLE WITHIN 180 NM ON EITHER SIDE OF 16N61W 19N50W 27N40W. BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA SOUTH AND SOUTHEAST OF THE CENTRAL ATLANTIC TROUGH. $$ MT