000 AXNT20 KNHC 111719 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU DEC 11 2014 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 1645 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 07N12W TO 07N16W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 02N51W. SCATTERED MODERATE CONVECTION 02N-06N E OF 30W. ...DISCUSSION... GULF OF MEXICO... A 1027 MB HIGH CENTERED OVER ARKANSAS-MISSISSIPPI ALONG WITH A MODERATE N-S PRESSURE GRADIENT IS ALLOWING CONTINUED COLD AIR ADVECTION WITH WINDS OF 5 TO 15 KT ACROSS THE EASTERN TWO-THIRDS OF THE GULF OF MEXICO. WEAK SE RETURN FLOW HAS COMMENCED IN THE EXTREME NORTHWESTERN GULF. NO SIGNIFICANT DEEP CONVECTION IS OCCURRING UNDER GENERALLY DRY AND SUBSIDENT FLOW. LITTLE CHANGE IS EXPECTED AT THE SURFACE FOR THE NEXT COUPLE OF DAYS AS THE HIGH REMAINS RATHER LOCKED IN PLACE OVER THE SOUTHEAST UNITED STATES. IN THE UPPER-LEVELS...STRONG WESTERLIES AS PART OF THE SUBTROPICAL JET STREAM ARE OBSERVED OVER THE GULF...ADVECTING MOISTURE AND HIGH CLOUDS BUT NO SIGNIFICANT PRECIPITATION. CARIBBEAN SEA... A STATIONARY FRONTAL BOUNDARY IS LOCATED FROM HAITI SOUTHWESTWARD TO JUST OFFSHORE OF NICARAGUA. THE COMBINATION OF HIGH PRESSURE NORTHWEST OF THE FRONT ALONG WITH LOW PRESSURE OVER PANAMA AND COLOMBIA ARE CONTRIBUTING TOWARD 20-25 KT NE WINDS OVER THE SOUTHWESTERN CARIBBEAN...AS SEEN BY THE 1524Z ASCAT SCATTEROMETER PASS. ELSEWHERE...THE TRADEWINDS ARE GENERALLY 10-20 KT ACROSS THE CARIBBEAN. ADDITIONALLY... SCATTERED MODERATE CONVECTION IS OBSERVED FROM 10-12N BETWEEN 75- 80W AS A RESULT OF THE FRONTAL BOUNDARY INTERACTING WITH THE EASTERN END OF THE PACIFIC ITCZ. ELSEWHERE...NO SIGNIFICANT DEEP CONVECTION IS OCCURRING OVER THE CARIBBEAN UNDER TYPICALLY SUBSIDENT AND DRY MID TO UPPER LEVEL WESTERLY TO SOUTHWESTERLY FLOW. WHILE THE FRONTAL BOUNDARY SHOULD DISSIPATE WITHIN A DAY OR SO...CONTINUED COOL AIR ADVECTION SHOULD OCCUR ACROSS THE NW CARIBBEAN DURING THE NEXT TWO DAYS. HISPANIOLA... A STATIONARY FRONTAL BOUNDARY IS LOCATED OVER HAITI THIS MORNING. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH IT...THOUGH ISOLATED LOW-TOPPED SHOWERS ARE POSSIBLE DURING THE NEXT TWO DAYS. WINDS ARE NE 10-15 KT NEAR HAITI AND THE SOUTHERN COAST OF DOMINICAN REPUBLIC WITH WEAKER WINDS ALONG THE NORTHERN COAST OF DOMINICAN REPUBLIC. OVER THE NEXT TWO DAYS...ISOLATED SHOWERS ARE POSSIBLE BUT THESE SHOULD NOT WIDESPREAD NOR DEEP CONVECTION. THE COASTAL WINDS SHOULD DIMINISH SOME DURING THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... A COLD FRONT EXTENDS FROM 32N59W SOUTHWESTWARD TO HISPANIOLA. MODERATE CONVECTION EXISTS WITHIN 60 NM OF THE FRONT NORTH OF 29N. THE FRONT SHOULD DISSIPATE WITHIN THE NEXT DAY OR SO. A NEW COLD FRONTAL BOUNDARY SHOULD REACH OUR NORTHEASTERN BOUNDARY BY FRIDAY MORNING A QUICKLY PROGRESS SOUTHEASTWARD. A 1014 MB SURFACE LOW IS LOCATED NEAR 26N40W WITH A TROUGH EXTENDING SOUTHEASTWARD A FEW HUNDRED NM. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THIS LOW...THOUGH EASTERLY WINDS OF 20 KT ARE PRESENT WITHIN THE NORTHERN SEMICIRCLE. AN UPPER-LEVEL LOW IS HELPING TO PRODUCT MODERATE CONVECTION FROM 25-30N BETWEEN 27- 30W. IT IS ANTICIPATED THAT THE LOW AND UPPER-LEVEL WILL DISSIPATE IN ABOUT A DAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LANDSEA