000 AXNT20 KNHC 291139 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC ...THE ITCZ... FROM THE SIERRA LEONE ALONG 10W TO 6N20W 5N30W 4N40W CURVING SOUTHWESTWARD...CROSSING THE EQUATOR ALONG 49W AND INTO NORTHEASTERN BRAZIL IN THE ILHA DE MARAJO NEAR 1S50W. ISOLATED MODERATE TO WIDELY SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE MOSTLY SOUTH OF 8N EAST OF 53W/SOUTH AMERICA. UPPER LEVEL SOUTHWESTERLY WIND FLOW IS SOUTH OF 10N60W 12N50W 20N32W 27N19W CROSSING OVER SOUTHERN WESTERN SAHARA. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW FROM THE CARIBBEAN SEA RIDGE COVERS THE GULF OF MEXICO SOUTHEAST OF 22N98W 27N90W AND BEYOND 31N80W. DRY AIR/SUBSIDENCE ALSO SOUTH OF THIS 22N98W 31N80W LINE. MIDDLE TO UPPER LEVEL MOISTURE IS WITHIN 250 NM IN TEXAS TO 400 NM IN GEORGIA AND ALABAMA NORTH AND NORTHWEST OF THE DRY AIR/SUBSIDENCE...COVERING THE U.S.A. GULF COAST STATES FROM TEXAS TO FLORIDA AND GEORGIA. A MIDDLE TO UPPER LEVEL TROUGH HAS DUG INTO NORTHERN MEXICO/NEW MEXICO/TEXAS AND THE SOUTHWESTERN U.S.A. ALONG 26N105W BEYOND 33N106W. THE ANTICYCLONIC FLOW ON WATER VAPOR IMAGERY THAT IS PREVALENT IS ON TOP OF A SHALLOW COLD FRONT THAT PASSES THROUGH SOUTHERN ALABAMA TO THE WATERS JUST OFF THE SOUTHEASTERN COAST OF LOUISIANA TO 25N94W TO THE SOUTHWESTERN CORNER OF THE AREA NEAR 19N96W. SHOWERS WERE EAST OF THE FRONT IN A SQUALL LINE WITHIN 15 TO 20 NM ON EITHER SIDE OF 27N90W 29N87W BEYOND 31N86W. THIS FRONT IS FORECAST TO MOVE EASTWARD IN THE GULF OF MEXICO DURING THE NEXT 24 HOURS...DISSIPATE AFTER 48 HOURS SOUTH OF 25N...AND THEN WEAKEN INTO A TROUGH FROM THE WESTERN ATLANTIC OCEAN TO FLORIDA AT 72 HOURS. A NEW FRONT MOVES TO A POSITION FROM THE FLORIDA PANHANDLE-NORTH CENTRAL GULF OF MEXICO-MEXICO JUST SOUTH OF TEXAS AT 72 HOURS. 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 BETWEEN 81W AND 82W IN THE WATERS NORTH OF PANAMA. BROKEN TO OVERCAST REMNANT CONVECTIVE DEBRIS CLOUDS ARE FROM 10N TO 12N BETWEEN 81W AND THE COAST OF CENTRAL AMERICA. MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW 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 11N65W 14N74W 19N87W. AN ALREADY DISSIPATED TROUGH IS ALONG 21N40W 16N50W 14N59W 13N64W. CLUSTERS OF MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE WITHIN 120 NM NORTH OF THIS 21N40W 13N64W LINE. SHOWERS MAY BE REACHING THE EASTERN CARIBBEAN SEA AT THIS TIME. 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 DISSIPATING STATIONARY FRONT CONTINUES ALONG 32N55W TO 32N60W 29N66W TO 28N71W. 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 27N38W 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. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 23N TO 30N BETWEEN 34W AND 40W. A NARROW LINE OF CLOUDS IS ALONG 25N35W 22N35W 20N37W 18N40W 12N50W 10N55W TO EXTREME NORTHEASTERN COASTAL VENEZUELA ALONG 60W FROM 8N/9N. SHOWERS ARE POSSIBLE IN THIS LINE OF CLOUDS. A SECONDARY TROUGH CURVES AWAY FROM THE GALE LOW PRESSURE CENTER ALONG 26N37W 22N40W 20N46W 19N54W. AN ALREADY DISSIPATED TROUGH IS ALONG 21N40W 16N50W 14N59W 13N64W. CLUSTERS OF MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE WITHIN 120 NM NORTH OF THIS 21N40W 13N64W LINE. SHOWERS MAY BE REACHING THE EASTERN CARIBBEAN SEA AT THIS TIME. $$ MT