000 AXNT20 KNHC 180008 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU JAN 17 2013 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH SOUTHERN COASTAL LIBERIA NEAR 4N8W TO 4N13N 4N17W. THE ITCZ CONTINUES FROM 4N17W TO 3N23W 2N30W 1N43W. MODERATE ISOLATED SHOWERS ARE BETWEEN THE ITCZ AND MONSOON TROUGH FROM 2N TO 6N. ...DISCUSSION... THE GULF OF MEXICO... SURFACE RIDGING BUILDS OVER THE GULF OF MEXICO WEST OF THE COLD FRONT AS A 1031 MB HIGH STARTS TO COME OFF THE MEXICO EAST COAST NEAR TAMPICO. AS 2100 UTC...THE COLD FRONT EXTENDS FROM JACKSONVILLE AND ENTERS THE GULF WATERS NEAR FORT MYERS...FROM THERE THE COLD FRONT CONTINUES SOUTHWESTWARD TO 25N83W 20N85W AND ENTERS THE YUCATAN PENINSULA NEAR 17N88W. A GALE WARNING IS JUST WEST OF THE COLD FRONT N OF 27N E OF 87W. BESIDES THE AREA OF GALE WARNING WHERE WINDS ARE FROM THE NW...NORTHERLY WINDS OF 15-25 KT SPREAD WEST OF THE COLD FRONT. BROKEN TO OVERCAST LOW CLOUDS AND LIGHT RAIN AS INDICATED BY THE RADAR IS WITHIN 110 NM EAST OF THE FRONT. FOG OR LOW VISIBILITY IS INDICATED FROM NAPLES FLORIDA SOUTHWESTWARD ALONG THE FRONT TO OVER THE YUCATAN PENINSULA. IN THE MIDDLE TO UPPER LEVELS A BROAD TROUGH WITH AXIS CROSSING THE EASTERN CONUS TO THE WEST ATLC SUPPORTS THE COLD FRONT AND ASSOCIATED SHOWERS ACTIVITY. WITHIN THE NEXT 24 HOURS...THE FRONT WILL BE OUT OF THE GULF. WINDS WILL BECOME NORTHEASTERLY COMING FROM A BROAD SURFACE HIGH THAT WILL BUILD OVER THE SOUTHEAST STATES AS WELL AS THE LOWEST MISSISSIPPI AND TENNESSEE VALLEY. THE CARIBBEAN SEA... WEAK PRESSURE GRADIENT IS OVER THE REGION. LIGHT TRADE WINDS OF MAINLY 10-15 KT COVER THE EASTERN AND CENTRAL CARIBBEAN. WINDS OF 20 KT CAN BE FOUND SOUTH OF THE HISPANIOLA AND OFF THE COLOMBIA COAST WHERE THE WINDS TURN NORTHEASTERLY. IN THE WESTERN CARIBBEAN...THE COLD FRONT FROM THE GULF STARTS TO ENTER THE AREA AND EXTENDS FROM THE WEST COAST OF CUBA NEAR 21N84W TO THE EAST COAST OF THE YUCATAN PENINSULA NEAR 17N88W. NORTHERLY AND NORTHEASTERLY WINDS OF 5-15 KT SPREAD OVER THE WESTERN CARIBBEAN. BESIDES LIGHT SHOWERS IN THE WESTERN CARIBBEAN ALONG THE FRONTAL BOUNDARY...THE REST OF THE REGION ENJOYS FROM FAIR WEATHER CONDITIONS BEING SUPPORTED BY UPPER LEVEL RIDGING AND DRY AIR SUBSIDENCE. EXPECT SIMILAR WIND CONDITIONS WITHIN 24 HOURS AND FOR THE COLD FRONT TO MOVE NORTH OF THE REGION. THE ATLANTIC OCEAN... IN THE WESTERN ATLC...A COLD FRONT STARTS TO MOVE OFF THE NORTHERN COAST OF FLORIDA AND ENTERS THE REGION NEAR 30N81W. AHEAD OF THE FRONT A SURFACE TROUGH IS ALONG 30N79W 28N79W THEN ENTERS THE FLORIDA PENINSULA SOUTH OF FORT PIERCE ALL THE WAY SOUTH TO NORTH OF THE FLORIDA KEYS. A GALE IS EXPECTED TO DEVELOP N OF 29N WITHIN 150 NM E OF THE FRONT. THE COLD FRONT AND SURFACE TROUGH ARE BEING SUPPORTED BY A BROAD TROUGH WITH AXIS CROSSING THE EASTERN CONUS TO THE WEST ATLC. LIGHT SHOWERS ACTIVITY ARE WEST OF 68W NORTH OF 24N. THE REMAINDER OF THE WEST ATLC IS BEING INFLUENCED BY SURFACE RIDGING FROM A 1024 MB HIGH NORTH OF THE REGION AND FAIR CONDITIONS PREVAILS SUPPORTED BY UPPER LEVEL RIDGING AND DRY AIR SUBSIDENCE. IN THE CENTRAL ATLC...A SURFACE LOW WITH EMBEDDED TROUGH IS NEAR 21N41W. THE TROUGH EXTENDS FROM THE LOW TO 17N40W 13N45W. SCATTERED SHOWERS ARE EAST OF THE LOW FROM 17N TO 24N BETWEEN 31W AND 41W. THIS LOW SYSTEM IS BEING SUPPORTED BY A CUT-OFF LOW IN THE UPPER LEVELS. IN THE EASTERN ATLC RIDGING FROM A 1027 MB HIGH LOCATED NEAR 32N16W DOMINATES. WIDESPREAD MODERATE TO ISOLATED STRONG SHOWERS ARE FROM 3N TO 16N BETWEEN 21W AND 41W. THIS CONVECTIVE ACTIVITY IS ASSOCIATED TO MOISTURE BEING ADVECTED FROM SOUTH OF THE EQUATOR. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS