000 AXNT20 KNHC 090545 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT JAN 09 2010 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N8W 3N21W 2N40W CROSSING THE EQUATOR NEAR 48W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2N-5N BETWEEN 9W-13W. ...DISCUSSION... GULF OF MEXICO... AS OF 0300 UTC...THE COLD FRONT CROSSES S FLORIDA NEAR FORT LAUDERDALE AND THE LOWER FLORIDA KEYS TO THE NE YUCATAN PENINSULA NEAR 21N87W. A DEEP LAYERED TROUGH IS OVER THE E US TO NEAR THE N GULF COAST BUT IS BEING OVERRIDDEN BY A STRONG UPPER RIDGE THAT IS ANCHORED IN THE CARIBBEAN COVERING THE GULF WATERS WITH SW UPPER FLOW. THIS UPPER FLOW IS DRAWING TROPICAL MOISTURE ACROSS S MEXICO AND THE GULF TO OVER THE SE US INCLUDING FLORIA...GEORGIA...ALABAMA...AND THE CAROLINAS GIVING THOSE STATES AND THE GULF DENSE CLOUD COVER WITH ISOLATED SHOWERS. A SURFACE RIDGE IS BUILDING BEHIND THE FRONT ANCHORED OVER THE CENTRAL PLAIN STATES PRODUCING THE STRONG NORTHERLY SURFACE FLOW OVER THE GULF BRINGING IN MORE COLD AIR AND COUPLED WITH THE INDUCTION OF MOISTURE COULD GIVE PORTIONS OF N FLORIDA SNOW FLURRIES LATER TONIGHT AND INTO SAT MORNING. THESE STRONG NORTHERLY WINDS WILL PERSIST BEHIND THE FRONT...WITH GALE FORCE WINDS OVER THE FAR SW GULF THROUGH TODAY THEN DIMINISH BY LATE SUN THROUGH WED AS HIGH PRESSURE CONTINUES TO BUILD S OVER THE GULF. CARIBBEAN SEA... AN UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE ENTIRE CARIBBEAN ANCHORED OVER N COLOMBIA PROVIDING A RELATIVELY SUBSIDENT ENVIRONMENT IN THE MID TO UPPER LEVELS ACROSS MOST OF THE BASIN WITH THE EXCEPTION OF THE FAR NW WHERE UPPER LEVEL MOISTURE IS BEING INTRODUCED FROM THE E PACIFIC REGION. A SURFACE TROUGH IS OVER THE FAR NW CARIBBEAN EXTENDING FROM W CUBA NEAR 22N84W TO THE GULF OF HONDURAS NEAR 17N87W WITH DENSE CLOUD COVER AND POSSIBLE ISOLATED SHOWERS ARE W OF THE TROUGH. A SHALLOW STATIONARY FRONT CLIPS THE FAR NE PORTION OF THE BASIN ACROSS THE VIRGIN ISLANDS AND SE PUERTO RICO TO NEAR 18N70W. A LOW LEVEL SHEAR AXIS EXTENDS FROM SW HAITI ACROSS JAMAICA THEN S TO OFF THE COAST OF NICARAGUA NEAR 13N83W DIVIDING THE LOW LEVEL EASTERLY WINDS TO THE E AND THE NORTHERLY WINDS TO THE W. THE COLD FRONT IN THE GULF OF MEXICO WILL MOVE INTO THE NW CARIBBEAN LATER THIS MORNING WITH STRONG TO NEAR GALE FORCE NORTHERLY WINDS BEHIND IT. THE FRONT WILL REACH THE MONA PASSAGE TO E COSTA RICA BY MON EVENING WHERE IT WILL STALL OUT AND DISSIPATE BY TUE. ATLANTIC OCEAN... AS OF 0300 UTC...A COLD FRONT ENTERS THE FAR W ATLC NEAR 32N73W AND EXTENDS INTO THE GULF OF MEXICO ACROSS FLORIDA NEAR FORT LAUDERDALE TO OVER THE LOWER FLORIDA KEYS. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC IS UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE ANCHORED BY A 1023 MB HIGH NEAR 28N48W. THIS SURFACE RIDGE IS BEING CUT OFF BY A SECOND COLD FRONT THAT ENTERS THE E/CENTRAL ATLC NEAR 32N34W EXTENDING SW ALONG 26N42W TO 23N49W THEN CONTINUES AS A STATIONARY FRONT ALONG 21N57W ACROSS THE VIRGIN ISLANDS INTO THE CARIBBEAN. ISOLATED SHOWERS ARE POSSIBLE WITHIN 150 NM EITHER SIDE OF THE COLD FRONT WITH POSSIBLE ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE STATIONARY FRONT. THIS FRONT IS SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH THAT IS N OF 23N BETWEEN 34W-55W. A WEAK 1022 MB HIGH IS E OF THE FRONT NEAR 25N29W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ WALLACE