000 AXNT20 KNHC 061803 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI DEC 06 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... A GALE WARNING EXISTS FOR A PORTION OF THE ATLANTIC OCEAN. THE 6- HOUR FORECAST CONSISTS OF...A COLD FRONT FROM 31N40W TO 26N41W TO 22N50W THEN WEAKENING FRONT TO 18N68W. N OF 27N BETWEEN 43W AND 52W NW TO N WINDS 30 TO 35 KT. SEAS 12 TO 17 FT IN MERGING NE AND NW SWELL. GALE CONDITIONS AND HIGH SEAS WILL CONTINUE THROUGH 36 HOURS. PLEASE READ THE HIGH SEAS FORECAST ...MIAHSFAT2/FZNT02 KNHC...FOR MORE DETAILS. ...THE ITCZ/THE MONSOON TROUGH... THE ITCZ EXTENDS FROM THE COAST OF SIERRA LEONE AT 7N12W TO 4N40W IN THE ATLANTIC. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE ITCZ. THE NORTHEAST PACIFIC MONSOON TROUGH EXTENDS ACROSS SOUTHERN CENTRAL AMERICA ALONG 9N83W TO THE COAST OF COLOMBIA AT 9N76W. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE MONSOON TROUGH OVER CENTRAL AMERICA OR THE CARIBBEAN SEA. ...DISCUSSION... THE GULF OF MEXICO... A COLD FRONT IS MOVING SLOWLY SOUTHWARD IN THE NORTHWESTERN PORTION OF THE GULF. IT EXTENDS FROM LOUISIANA TO EASTERN MEXICO WITH COOL AIR BANKING UP ALONG THE SIERRA MADRE MOUNTAINS. SOUTH TO SOUTHEASTERLY WINDS AHEAD OF THE FRONT ARE GENERALLY MODERATE TO FRESH BREEZE CONDITIONS. BEHIND THE FRONT...THE NORTHERLY WINDS ARE STRONGER WITH UP TO STRONG BREEZE CONDITIONS OCCURRING. LOW CLOUD CEILINGS...VISIBILITIES OF A FEW MILES OR LESS WITH FOG...AND SCATTERED SHOWERS CONTINUE BEHIND THE FRONT. HOWEVER...NO THUNDERSTORM ACTIVITY IS ASSOCIATED WITH THE FRONTAL BOUNDARY. IN THE UPPER LEVELS...SUBSIDENT ANTICYCLONIC FLOW AROUND A HIGH IN THE NORTHWESTERN CARIBBEAN SEA DOMINATES THE FLOW OVER THE GULF OF MEXICO. A SURFACE RIDGE FROM THE ATLANTIC EXTENDING ACROSS THE FLORIDA PENINSULA EXTENDS INTO THE GULF OF MEXICO TO 28N88W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT4/FZNT24 KNHC...FOR MORE DETAILS. ...HISPANIOLA... NO ORGANIZED DEEP CONVECTION IS EXPECTED FOR HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF DAYS. SOME SHOWERS ARE POSSIBLE OVER THE EASTERN-FACING TERRAIN OF DOMINICAN REPUBLIC DUE TO UPSLOPE FLOW FROM THE NORTHEASTERLY TRADEWINDS. DRY SUBSIDENT AIR IN THE UPPER LEVELS IS PRESENT OVER THE ISLAND. THE REST OF THE CARIBBEAN SEA... A NORTHEAST TO SOUTHWEST ORIENTED UPPER LEVEL TROUGH EXTENDS FROM THE CENTRAL ATLANTIC INTO THE NORTHEASTERN CARIBBEAN SEA. THIS ALONG WITH THE WESTERN END OF A COLD FRONTAL BOUNDARY JUST NORTH OF THE LESSER ANTILLES IS CONTRIBUTING TOWARD SHOWER AND THUNDERSTORM ACTIVITY OVER PORTIONS OF THE NORTHERN LESSER ANTILLES. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT 05/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...WAS 1.65 IN SAN JUAN PUERTO RICO AND 1.44 IN ST THOMAS VIRGIN ISLANDS. CONTINUED POTENTIAL FOR SOME HEAVY RAINFALL IS POSSIBLE DURING THE NEXT TWO DAYS OVER THE NORTHERN LESSER ANTILLES. A MODEST PRESSURE GRADIENT IS FORCING MODERATE TO FRESH BREEZE EASTERLY TRADEWINDS OVER MOST OF THE CARIBBEAN WITH THE EXCEPTION OF STRONG BREEZE IN THE WINDWARD PASSAGE AND THE CENTRAL CARIBBEAN. THESE CONDITIONS SHOULD CONTINUE DURING THE NEXT COUPLE OF DAYS. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS. THE REST OF THE ATLANTIC OCEAN... A COLD FRONT CURRENTLY EXTENDS FROM A 1004 MB LOW NORTH OF OUR AREA AT 34N43W TO 31N40W THEN SOUTHWESTWARD TO 20N64W JUST NORTH OF THE LESSER ANTILLES. WEST OF 56W...SCATTERED DEEP CONVECTION IS OCCURRING WITHIN 90 NM OF THE FRONT. AS MENTIONED ABOVE ...SHOWERS AND THUNDERSTORMS ARE ALSO BEING SUPPORTED BY A VIGOROUS UPPER LEVEL TROUGH. EAST OF 56W...SCATTERED SHOWERS ARE OCCURRING WITHIN 60 NM OF THE FRONT. A TROUGH EXTENDING FROM 14N41W SOUTHWARD TO 8N42W OVER THE CENTRAL ATLANTIC IS PRODUCING SCATTERED SHOWERS WITHIN 240 NM EAST OF THE TROUGH AXIS. THIS FEATURE MAY BECOME ABSORBED BY THE ADVANCING FRONTAL BOUNDARY IN THE NEXT DAY OR TWO. AN ATLANTIC OCEAN 1029 MB HIGH PRESSURE CENTER IS NEAR 33N63W. A SURFACE RIDGE EXTENDS FROM THE 1029 MB HIGH CENTER...ACROSS BERMUDA...THROUGH 31N74W...TO FLORIDA NEAR 29N81W. A WEAK 1018 MB HIGH CENTER IS CENTERED AT 22N35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CWL