000 AXNT20 KNHC 101718 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU DEC 10 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 MONSOON TROUGH AXIS EXTENDS FROM 03N AND THE PRIME MERIDIAN TO 02N04W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N09W TO 05N25W TO 06N35W TO 05N44W. SCATTERED MODERATE CONVECTION IS S OF 01N E OF 03W...FROM 02N-12N BETWEEN 17W-26W... AND FROM 04N-08N BETWEEN 26N-43W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE NORTHERN FLORIDA PENINSULA NEAR 30N82W TO THE CENTRAL GULF OF MEXICO NEAR 26N81W TO 23N98W. DRY AND STABLE AIR IS FILLING IN BEHIND THE TROUGH WHILE DEEP TROPICAL MOISTURE IS BEING ADVECTED FROM THE TROPICAL NORTHEAST PACIFIC OCEAN TO ACROSS SOUTHEAST MEXICO AND THEN NORTHEAST ACROSS THE SOUTHERN GULF OF MEXICO AHEAD OF THE TROUGH. A WEAK SURFACE TROUGH IS OVER THE SOUTHEAST GULF FROM 26N85W TO 23N83W WITH SCATTERED SHOWERS AND ISOLATED TSTMS IN THE VICINITY. THE SURFACE TROUGH WILL WEAKEN AND DRIFT TO THE EAST THROUGH TONIGHT. OTHERWISE 1018 MB HIGH PRESSURE IS IN THE CENTRAL GULF NEAR 25N88W WITH RIDGING EXTENDING FROM THE FLORIDA BIG BEND TO NEAR VERACRUZ MEXICO WHICH IS DOMINATING THE WEATHER AT THE SURFACE. GENTLE TO MODERATE ANTICYCLONIC FLOW AND 1-3 FT SEAS ARE FOUND ACROSS THE BASIN. THE HIGH CENTER WILL GRADUALLY SHIFT NORTHEAST THROUGH FRIDAY MORNING ALLOWING FOR RETURN FLOW IN THE WESTERN GULF TO INCREASE TO MODERATE TO FRESH. BY SATURDAY MORNING RETURN FLOW CONTINUES TO INCREASE TO FRESH TO STRONG IN THE WESTERN GULF AS LOW PRESSURE MOVES INTO NORTHERN TEXAS WHILE DEEPENING INCREASING THE PRESSURE GRADIENT. CARIBBEAN SEA... A FLATTENING MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE NORTHEAST CARIBBEAN NEAR THE ANEGADA PASSAGE TO ACROSS NORTHERN COLOMBIA. WATER VAPOR SATELLITE IMAGERY INDICATES MAINLY DRY AND STABLE AIR S OF 18N. WEST OF THE TROUGH...MIDDLE TO UPPER LEVEL RIDGING IS MOVING IN FROM THE SOUTHWEST WITH MOISTURE BEING ADVECTED UP AROUND THE RIDGE ACROSS THE NORTHWEST CARIBBEAN. THE TAIL END OF A COLD FRONT EXTENDS ACROSS WESTERN CUBA THEN BECOMES A TROUGH FROM 22N81W TO THE YUCATAN PENINSULA NEAR 19.5N87W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FOUND N OF 20N...AND ALSO BETWEEN CUBA AND JAMAICA...AND HAITI AND ACROSS THE WINDWARD PASSAGE WHERE A WEAK UPPER LEVEL IMPULSE IS ROTATING THROUGH. THE SURFACE TROUGH WILL LINGER IN THE NORTHWEST CARIBBEAN THROUGH FRIDAY WHILE DRIFTING TO THE EAST. FRESH TO STRONG TRADES ARE IN THE SOUTH CENTRAL CARIBBEAN DUE TO A TIGHT PRESSURE GRADIENT BETWEEN 1008 MB LOW PRESSURE OVER NORTHERN COLOMBIA NEAR 09N75W AND CENTRAL ATLC RIDGING NE OF THE AREA. MAINLY MODERATE TO LOCALLY FRESH TRADES ARE FOUND ELSEWHERE...EXCEPT GENTLE N-NE FLOW IN THE NORTHWEST CARIBBEAN EARLY THIS AFTERNOON. LITTLE CHANGE IN THESE CONDITIONS IS EXPECTED DURING THE NEXT 24-48 HOURS...EXCEPT IN THE NORTHWEST CARIBBEAN WHERE MODERATE NE-E TRADES WILL BECOME ESTABLISHED FRIDAY NIGHT THROUGH SATURDAY. ...HISPANIOLA... A WEAK UPPER LEVEL DISTURBANCE IS MOVING ACROSS THE AREA WHICH MAY CREATE ENOUGH INSTABILITY TO SUPPORT ISOLATED TSTMS THIS AFTERNOON WHILE SCATTERED SHOWERS ARE ALREADY SPREADING EASTWARD ACROSS HAITI. MORE STABLE CONDITIONS SHOULD MOVE IN LATER TODAY AND TONIGHT AS THE DISTURBANCE LIFTS OUT. A MIDDLE TO UPPER LEVEL TROUGH MAY MOVE CLOSE ENOUGH TO THE ISLAND BY SATURDAY TO INCREASE THE POSSIBILITY OF CONVECTION. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH IS MOVING INTO THE NW PORTION EXTENDING FROM NEW ENGLAND SOUTHWARD THROUGH 32N72W TO NEAR CAPE CANAVERAL FLORIDA. WATER VAPOR SATELLITE IMAGERY SHOWS DRY AND STABLE AIR MOVING IN BEHIND THE TROUGH WHILE PLENTIFUL MOISTURE IS BEING ADVECTED FROM THE NORTHEAST PACIFIC OCEAN ACROSS THE SOUTHEAST GULF OF MEXICO AND NORTHWEST CARIBBEAN TO OVER THE REMAINDER OF THE SW N ATLC BASIN. A SOMEWHAT COMPLEX WEATHER PATTERN IS FOUND AT THE SURFACE WITH A COLD FRONT REACHING FROM 32N45W TO 30N56W WHERE IT BECOMES STATIONARY TO 30.5N61W...THEN AS A WARM FRONT THROUGH 31N67W TO 1012 MB LOW PRESSURE NEAR 28N70W. A WEAK COLD FRONT CONTINUES FROM THE LOW TO N CENTRAL CUBA. NUMEROUS SHOWERS AND SCATTERED TSTMS UNDER UPPER LEVEL DIFFLUENCE ARE N OF 25N BETWEEN 60W-69W. A NEW FRONT IS IN THE PROCESS OF FORMING FROM OFFSHORE OF THE CAROLINAS THROUGH 32N76W TO 29N80W...WHILE A PRE-FRONTAL TROUGH EXTENDS FROM 31N73W TO 28N80W. ISOLATED SHOWERS AND TSTMS ARE IN THE VICINITY OF BOTH OF THESE FEATURES. ADDITIONAL CONVECTION IS MOVING ACROSS THE BAHAMAS AND STRAITS OF FLORIDA. THE SURFACE LOW WILL MOVE NE TO NEAR 31N64W THIS EVENING DRAGGING THE COLD FRONT IN ITS WAKE. THE LOW WILL QUICKLY MOVE NE-E REACHING 32N48W BY SATURDAY MORNING. MEANWHILE THE SOUTHERN PORTION OF THE FRONT WILL GET LEFT BEHIND FROM 26N65W TO 23N77W BY SAT MORNING WITH HIGH PRESSURE BUILDING IN NORTH OF THERE. FRESH TO STRONG SOUTHERLY FLOW WILL MOVE OUT AHEAD OF THE LOW AND COLD FRONT WITH MAINLY GENTLE TO MODERATE WINDS ELSEWHERE ACROSS THE SW N ATLC. THESE CONDITIONS CONTINUE THROUGH FRIDAY NIGHT WITH AN AREA OF FRESH TO STRONG NE-E WINDS LIKELY DEVELOPING JUST NORTH OF THE REMNANT FRONTAL PORTION WHERE A TIGHT PRESSURE GRADIENT WILL DEVELOP. ELSEWHERE...A DISSIPATING COLD FRONT REACHES FROM 32N35W TO 27N43W. HIGH PRESSURE AT 1022 MB NEAR 27N50W DOMINATES THE REMAINDER OF THE AREA N OF 10N. THIS HIGH WILL SHIFT SE REACHING 26N45W TONIGHT INTO FRIDAY. A SURFACE TROUGH IS EMBEDDED IN THE ITCZ FROM 09N44W TO 01N46W WITH SCATTERED SHOWERS S OF 10N BETWEEN 40W-50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LEWITSKY