000 AXNT20 KNHC 091736 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED DEC 09 2015 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. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N10W TO 04N30W TO 05N39W THEN RESUMES FROM 04N43W TO 01N49W. A SURFACE TROUGH IS ANALYZED FROM 10N38W TO 01N42W. SCATTERED MODERATE CONVECTION IS FROM 02N-07N BETWEEN 22W-31W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH REACHES FROM THE TENNESSEE VALLEY TO THE SOUTH ACROSS WESTERN ALABAMA THEN ACROSS EASTERN LOUISIANA THROUGH THE NW GULF NEAR 27N96W TO ACROSS NORTHERN MEXICO. A SURFACE TROUGH IS IN THE EASTERN GULF ANALYZED FROM 27N85W TO 23N85W. A STATIONARY FRONT EXTENDS FROM THE STRAITS OF FLORIDA TO THE YUCATAN CHANNEL WHERE IT HAS BEEN MEANDERING FOR DAYS. ISOLATED SHOWERS AND TSTMS ARE OCCURRING NEAR THE FRONTAL BOUNDARY. SURFACE HIGH PRESSURE AT 1019 MB IS LOCATED IN THE NORTHERN GULF NEAR 29N87W WITH BROAD RIDGING DOMINATING THE REMAINDER OF THE BASIN. THE FRONT WILL DISSIPATE OR SHIFT SOUTH TONIGHT AS THE HIGH AND RIDGING BUILD SOUTHWARD AS WITH WANING UPPER LEVEL SUPPORT. GENTLE ANTICYCLONIC FLOW WITH 1-3 FT SEAS WILL PREVAIL THROUGH THE END OF THE WEEK...EXCEPT MODERATE TO LOCALLY FRESH RETURN FLOW WILL DEVELOP IN THE WESTERN GULF THU NIGHT THROUGH FRI. SEAS WILL BUILD TO 4-6 FT IN THE WESTERN GULF AS A RESULT. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE EASTERN DOMINICAN REPUBLIC NEAR 18N69W TO ACROSS THE CENTRAL CARIBBEAN TO WESTERN COLOMBIA NEAR 08N76W. MAINLY DRY AND STABLE CONDITIONS PREVAIL E OF 80W...WHILE DIVERGENT FLOW ALOFT IS W OF 80W AROUND A LARGE UPPER LEVEL ANTICYCLONE CENTERED IN THE TROPICAL NORTHEAST PACIFIC OCEAN SW OF CENTRAL AMERICA. A WEAKENING STATIONARY FRONT REACHES FROM THE YUCATAN CHANNEL NEAR 22N85.5W TO 1013 MB LOW PRESSURE NEAR 19N87W WITH A SURFACE TROUGH EXTENDING FROM THE LOW TO NEAR THE HONDURAS/GUATEMALA BORDER. THIS FRONT IS RAPIDLY LOSING ITS UPPER LEVEL SUPPORT AND WILL LIKELY FINALLY DISSIPATE TONIGHT. ISOLATED TSTMS ACTIVITY HAS DEVELOPED BETWEEN EASTERN JAMAICA AND SW HAITI AS A WEAK UPPER LEVEL IMPULSE ROTATES THROUGH THE AREA. FRESH TO STRONG TRADES AND 7-9 FT SEAS PREVAIL IN THE S CENTRAL CARIBBEAN DUE TO A TIGHT PRESSURE GRADIENT BETWEEN 1008 MB LOW PRESSURE OVER NORTHERN COLOMBIA NEAR 09.5N74.5W AND CENTRAL ATLC HIGH PRESSURE RIDGING NE OF THE AREA. MODERATE TO LOCALLY FRESH TRADES PREVAIL ELSEWHERE...EXCEPT IN THE NW CARIBBEAN WHERE LIGHT AND VARIABLE WINDS ARE ON EITHER SIDE OF THE SURFACE FEATURES. THESES CONDITIONS WILL NOT VARY MUCH THROUGH THE NEXT 24-48 HOURS... EXCEPT MODERATE TRADES WILL TAKE OVER IN THE NW CARIBBEAN AS WELL ONCE THE STATIONARY FRONT AND LOW PRESSURE AREA DISSIPATE. ...HISPANIOLA... MOSTLY CLEAR SKIES AND FAIR CONDITIONS ARE NOTED ACROSS THE ISLAND THIS MORNING INTO THE EARLY AFTERNOON HOURS. A MIDDLE TO UPPER LEVEL TROUGH IS EXITING THE AREA TO THE EAST WITH UPPER LEVEL RIDGING BUILDING IN ITS WAKE. A MAINLY DRY AND STABLE ATMOSPHERE IS ANTICIPATED...HOWEVER AN ISOLATED AFTERNOON TSTM CANNOT BE RULED OUT. ATLANTIC OCEAN... SOUTHWESTERLY FLOW ALOFT PREVAILS ACROSS MUCH OF THE SW NORTH ATLC REGION EAST OF A MIDDLE TO UPPER LEVEL TROUGH NOTED ON WATER VAPOR IMAGERY WHICH IS MOVING INTO THE NORTHERN GULF AND APPROACHING THE SE GEORGIA/NE FLORIDA COAST. A WEAKENING MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS TO THE SOUTHEAST EXTENDING FROM NEAR 29N76W TO JUST EAST OF THE TURKS AND CAICOS ISLANDS NEAR 21N70W. BOTH OF THESE FEATURES ALOFT ARE SUPPORTING A COLD FRONT WHICH EXTENDS FROM 32N59W TO 26N74W WHERE IT BECOMES STATIONARY ACROSS THE NORTHERN BAHAMAS TO THE STRAITS OF FLORIDA. A SURFACE TROUGH IS ANALYZED NW OF THE FRONT EXTENDING FROM NEAR 30N69W TO 27N78W. NUMEROUS SHOWERS AND SCATTERED TSTMS ARE OCCURRING ACROSS THE MAJORITY OF THE AREA N OF 23N/24N W OF 62W. WEAK LOW PRESSURE MAY DEVELOP ALONG THE FRONT NEAR 29N71W BY SUNRISE THU LIFTING NE OF THE AREA TO NEAR 33N59W BY SUNRISE FRI TAKING THE TRAILING COLD FRONT IN ITS WAKE. THE FRONT WILL EXTEND FROM THE LOW THROUGH 27N65W TO NEAR THE TURKS AND CAICOS ISLANDS BY SUNRISE FRI WITH SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. MAINLY LIGHT TO MODERATE WINDS WILL PREVAIL THROUGH THE END OF THE WEEK...EXCEPT FRESH TO LOCALLY STRONG IN AREAS OF CONVECTION. ANOTHER COLD FRONT IS LOCATED TO THE EAST REACHING FROM 32N42W TO 28.5N50W. THIS FRONT WILL CONTINUE EASTWARD WITH NW SWELLS OF 8-11 FT PROPAGATING IN BEHIND IT. A 1023 MB SURFACE HIGH IS LOCATED SOUTH OF THE COLD FRONT NEAR 27N52W WITH A RIDGE AXIS EXTENDING FROM EAST TO WEST THROUGH THE HIGH. A SURFACE TROUGH IS LOCATED TO THE SOUTH IN THE DEEP TROPICS AS IS DESCRIBED IN THE CONVECTION SECTION ABOVE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LEWITSKY