000 AXNT20 KNHC 290555 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT DEC 29 2007 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 0515 UTC ...THE ITCZ... FROM THE SIERRA LEONE ALONG 11W TO 6N20W 5N30W 4N40W CURVING SOUTHWESTWARD...CROSSING THE EQUATOR ALONG 48W AND INTO NORTHEASTERN BRAZIL IN THE NORTHEASTERN ILHA DE MARAJO. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE SOUTH OF 7N EAST OF 53W/SOUTH AMERICA. UPPER LEVEL SOUTHWESTERLY WIND FLOW IS SOUTH OF 10N60W 13N48W 20N33W 26N20W CROSSING OVER SOUTHERN MOROCCO. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW FROM THE CARIBBEAN SEA RIDGE COVERS THE GULF OF MEXICO SOUTHEAST OF 22N98W 20N90W AND BEYOND 31N80W. DRY AIR/SUBSIDENCE ALSO SOUTH OF THIS 22N98W 31N80W LINE. MIDDLE TO UPPER LEVEL MOISTURE IS WITHIN 300 NM TO 360 NM NORTH AND NORTHWEST OF THE DRY AIR/SUBSIDENCE... COVERING THE U.S.A. GULF COAST STATES FROM TEXAS TO FLORIDA/ GEORGIA. A MIDDLE TO UPPER LEVEL TROUGH HAS DUG INTO MEXICO AND THE SOUTHWESTERN U.S.A. ALONG 26N104W BEYOND 32N108W. THE ANTICYCLONIC FLOW ON WATER VAPOR IMAGERY THAT DOMINATES THE AREA IS ON TOP OF A SHALLOW COLD FRONT THAT PASSES THROUGH SOUTHEASTERN MISSISSIPPI/SOUTHEASTERN LOUISIANA...INTO THE WEST CENTRAL GULF OF MEXICO AND TO THE SOUTHWESTERN CORNER OF THE AREA NEAR 19N96W. A SQUALL LINE HAS BEEN TO THE EAST OF THE FRONT AND IS ALONG 29N88W BEYOND 32N84W. ISOLATED MODERATE SHOWERS ARE WITHIN 15 TO 30 NM ON EITHER SIDE OF 28N90W 30N86W. THIS FRONT IS FORECAST TO MOVE EASTWARD IN THE GULF OF MEXICO AND DISSIPATE AFTER 48 HOURS. A NEW FRONT STARTS TO DEVELOP AT 72 HOURS IN THE NORTHWESTERN GULF OF MEXICO. THE CARIBBEAN SEA... MIDDLE TO UPPER LEVEL ANTICYCLONIC WIND FLOW EXTENDS FROM THE WEST CENTRAL CARIBBEAN SEA NORTHWARD IN ORDER TO COVER FLORIDA...AND NORTHEASTWARD BEYOND 32N69W IN ORDER TO COVER THE WESTERN ATLANTIC OCEAN. UPPER LEVEL MOISTURE THAT HAS BEEN CONFINED MOSTLY TO THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA IS BEING PUSHED NORTHWESTWARD ACROSS THE COASTAL PLAINS/COASTAL WATERS OF CENTRAL AMERICA AND EVENTUALLY ACROSS CUBA AND EVEN TO THE NORTHERN ISLANDS OF THE BAHAMAS. SOME CELLS OF SHOWERS IN THE WATERS JUST NORTH OF THE CENTRAL PANAMA COAST HAVE BEEN DISSIPATING AND MOVING SLIGHTLY NORTHWARD. SCATTERED STRONG SHOWERS REMAIN INTACT FROM 9N TO 10N BETWEEN 82W AND 83W AT THE WESTERN END OF PANAMA. MIDDLE TO UPPER LEVEL ANTICYCLONIC EVENTUALLY HAS BECOME SUCH THAT IT COVERS THE ENTIRE CARIBBEAN SEA BASIN. SHOWERS ARE POSSIBLE IN BROKEN LOW CLOUDS IN SURFACE EASTERLY WIND FLOW...NORTH OF 11N63W 14N74W 19N86W. AN ALREADY DISSIPATED ATLANTIC OCEAN TROUGH IS ALONG THE LINE 19N43W 15N54W 14N62W. CLUSTERS OF MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE WITHIN 120 NM NORTH OF THIS 19N43W 14N62W LINE. SHOWERS MAY BE REACHING THE EASTERN CARIBBEAN SEA AT THIS TIME MOVING SOUTHWESTWARD FROM THE ATLANTIC OCEAN. THE ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL ANTICYCLONIC WIND FLOW EXTENDS FROM THE WEST CENTRAL CARIBBEAN SEA NORTHWARD IN ORDER TO COVER FLORIDA...AND NORTHEASTWARD BEYOND 32N69W IN ORDER TO COVER THE ATLANTIC OCEAN NORTH OF 16N WEST OF 54W. A COLD FRONT PASSES THROUGH 32N59W TO 31N61W. A DISSIPATING STATIONARY FRONT CONTINUES ALONG 31N61W 29N65W 28N68W. THE MIDDLE TO UPPER LEVEL SUPPORT FOR THIS FEATURE HAS DISAPPEARED BECAUSE OF THE RIDGE. A DEEP LAYER CYCLONIC CIRCULATION CENTER REMAINS IN THE CENTRAL ATLANTIC OCEAN NEAR 26N38W ON WATER VAPOR IMAGERY...AND A 1008 MB GALE LOW PRESSURE CENTER IS NEAR 26N38W. THE DEEP LAYER TROUGH RUNS FROM THE 26N37W CYCLONIC CENTER TO 21N38W 14N45W TO 13N60W. A NARROW LINE OF CLOUDS IS ALONG 24N35W 20N37W 18N40W 12N50W 10N54W TO EXTREME NORTHEASTERN COASTAL VENEZUELA ALONG 60W FROM 8N/9N. SHOWERS ARE POSSIBLE IN THIS LINE OF CLOUDS. A SECONDARY TROUGH COMES FROM THE GALE LOW PRESSURE CENTER ALONG THE LINE 25N37W 22N40W 20N45W 19N53W. AN ALREADY DISSIPATED TROUGH IS ALONG THE LINE 19N43W 15N54W 14N62W. CLUSTERS OF MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE WITHIN 120 NM NORTH OF THIS 19N43W 14N62W LINE. SHOWERS MAY BE REACHING THE EASTERN CARIBBEAN SEA AT THIS TIME. $$ MT