000 AXNT20 KNHC 311144 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST THR DEC 31 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 1130 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED FROM WEST AFRICA...OVER THE SOUTH COAST OF SIERRA LEONE NEAR 7N12W...THROUGH 5.5N20W 4N30W 3.5N40W...TO NORTHEAST BRAZIL NEAR THE CITY OF BELEM AT 1S45W. THE ITCZ HAS BEEN RELATIVELY CALM OVER THE PAST 6 HOURS. ONLY SCATTERED WEAK CONVECTION IS OBSERVED WITHIN 150 NM OF THE ITCZ BETWEEN 17W AND 30W. ...DISCUSSION... THE GULF OF MEXICO... A 1016 MB LOW IS CENTERED OVER THE WESTERN COAST OF ALABAMA NEAR 30N87W. A COLD FRONT EXTENDS SOUTHWEST FROM THE LOW CENTER ALONG 25N90W 23N92W 22N94W. THIS FRONT IS SLOWLY MOVING EASTWARD INTO THE EASTERN BASIN. SHIP AND BUOY OBSERVATION SHOW NORTHWEST WINDS 5 TO 10 KTS BEHIND THE FRONT. TO THE EAST OF THE FRONT NORTH OF 23N...OBSERVATIONS SHOW SOUTHEAST WINDS 10 TO 20 KTS. A WARM FRONT IS ANALYZED EXTENDING SOUTHEAST FROM THE LOW CENTER ALONG 29N85W 28N83W. THIS LOW PRESSURE SYSTEM WILL CONTINUE A NORTHEAST TRAJECTORY OVER THE NEXT 24 HOURS. IN THE UPPER LEVELS OF THE ATMOSPHERE...A WIDE TROUGH COVERING MUCH OF THE CENTRAL CONTINENTAL US IS PRODUCING LIGHT SOUTHWEST UPPER LEVEL FLOW OVER THE ENTIRE GULF. WATER VAPOR IMAGERY SHOWS THIS UPPER LEVEL FLOW TRANSPORTING MOISTURE FROM THE EASTERN TROPICAL PACIFIC INTO THE GULF OF MEXICO TO SUPPORT CONVECTION IN THIS REGION. RADAR IMAGERY SHOWS A BROAD LINE OF WEAK TO MODERATE SHOWERS MOVING ALONG THE NORTHEAST GULF COAST. THIS SHOWERS ARE MOVING PARALLEL TO THE 30N LINE THROUGH THE FLORIDA PANHANDLE. PRECIPITATION WILL MOVE ACROSS NORTHERN FLORIDA INTO THE WESTERN ATLANTIC OCEAN OVER THE NEXT 24 TO 36 HOURS. THE CARIBBEAN SEA... UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE MOST OF THE CARIBBEAN BASIN...BRINGING STRONG SUBSIDENCE OF AIR ALOFT AND SUPPRESSING DEEP CONVECTION ACROSS THE BASIN. NEVERTHELESS...THE SOUTH END TIP OF A ATLANTIC COLD FRONT IS PASSING 50 NM SOUTH OF THE ISLAND OF PUERTO RICO TO NEAR 15N70W. THUS...WEAK CONVECTION IS OBSERVED NORTH OF 15N BETWEEN 62W AND 72W. DOPPLER RADAR IMAGERY SHOWS AN AREA OF WEAK ISOLATED SHOWERS MOVING IN SOUTHWEST DIRECTION 30 NM SOUTH OF PUERTO RICO. SATELLITE IMAGERY INDICATES THESE SHOWERS MAY EXTEND SOUTHWESTWARD TO 15N70W. SHIP AND BUOY OBSERVATIONS SHOW NORTHEAST WINDS 10 TO 20 KTS BEHIND OF THE FRONTAL BOUNDARY. ELSEWHERE...EASTERLY WINDS 10 TO 20 KTS ARE REPORTED ACROSS THE BASIN. THE ACTIVITY IN THE NORTHEAST BASIN WILL LESSEN AS THE FRONT SLOWLY MOVES OUT OF THE AREA. HIGH PRESSURE WILL KEEP DEEP CONVECTION FROM HAPPENING OVER THE CARIBBEAN. THEREFORE...EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... AN UPPER LEVEL RIDGE IS OVER THE WESTERN ATLANTIC...MOVING ALONG A SURFACE HIGH PRESSURE OF 1030 MB INTO THE WESTERN BASIN. THUS LIGHT SURFACE ANTICYCLONIC FLOW IS OBSERVED IN THIS REGION. A SHARP UPPER LEVEL TROUGH IS MOVING ACROSS THE CENTRAL ATLANTIC. THE TAIL END OF A COLD FRONT ENTERS THE CENTRAL ATLANTIC NEAR 30N40W AND EXTENDS SOUTHWEST ALONG 21N50W 18N60W TO SOUTH OF THE ISLAND OF PUERTO RICO. BROKEN COLD AIR STRATOCUMULUS CLOUDS ARE WEST OF THE FRONT TO 70W. WEAK CONVECTION IS OCCURRING WITHIN 120 NM EAST OF THE COLD FRONT. GALE FORCE WINDS ARE EXPECTED TO DEVELOP OVER THE NEXT 24 TO 36 HOURS WITHIN 300 NM WEST OF THE COLD FRONT NORTH OF 29N. AN UPPER LEVEL RIDGE OVER THE EASTERN ATLANTIC IS FEEDING A 1022 MB HIGH NEAR 30N26W. EXPECT OVER THE NEXT 24 TO 36 HOURS FOR THE COLD FRONT TO MOVE EAST INTO THE EASTERN ATLANTIC NEAR 35W WITH CONVECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ GARCIA