000 AXNT20 KNHC 031754 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU DEC 03 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. ...SPECIAL FEATURES... A A COLD FRONT IS ANALYZED FROM CENTRAL FLORIDA JUST SOUTH OF TAMPA BAY SW TO NEAR 21.5N94.5W THEN TURNS SHARPLY SOUTHWARD ACROSS THE CENTRAL BAY OF CAMPECHE AND CONTINUES INLAND FROM ABOUT 20 MILES EAST OF COATZACOALCOS MEXICO TO EASTERN PORTIONS OF THE ISTHMUS OF TEHUANTEPEC. A STRONG PRESSURE GRADIENT BETWEEN THE FRONT AND 1028 MB HIGH PRESSURE ACROSS NE MEXICO IS GENERATING GALE FORCE NORTHERLY WINDS S OF 21N W OF 94W...WHILE NORTHERLY WINDS 20-30 KT PREVAIL ELSEWHERE W OF THE FRONT S OF 26N...AND GALES HAVE BEGUN ON THE PACIFIC SIDE OF THE ISTHMUS ACROSS THE GULF OF TEHUANTEPEC. THESE NORTHERLY GALES ARE EXPECTED TO SHIFT SLIGHTLY SOUTHWARD BY AFTERNOON...TO THE BAY OF CAMPECHE WATERS SOUTH OF 20N...AND INCREASE TO 40 KT BEFORE GRADUALLY DIMINISHING BELOW GALE FORCE TONIGHT. SEE THE LATEST FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... MODEL DATA AND OBSERVATIONS SUGGEST THAT THERE IS NO MONSOON TROUGH PRESENT ACROSS THE W AFRICAN REGION. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM CAMEROON NEAR 10N10E TO 02N05E TO 06N23W TO 03.5N38W TO NEAR THE MOUTH OF RIO OIPOQUE NEAR 04N52W. WIDELY SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 90 NM OF AXIS 05E-05W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM S AND 210 NM N OF AXIS FROM 31W-52W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS MIDDLE TO UPPER LEVEL LOW IS NOTED IN WATER VAPOR IMAGERY SHIFTING NE AND OUT OF THE GREAT LAKES REGION...WITH A SOMEWHAT BROAD MIDDLE TO UPPER TROUGH TRAILING SOUTHWEST OVER THE MID-MISSISSIPPI RIVER VALLEY AND SOUTHERN PLAINS TO NORTHERN MEXICO THEN THE SOUTHERN TIP OF BAJA MEXICO. THE TROUGH IS SUPPORTING A COLD FRONT EXTENDING CENTRAL FLORIDA JUST SOUTH OF TAMPA BAY SW TO NEAR 21.5N94.5W THEN TURNS SHARPLY SOUTHWARD ACROSS THE CENTRAL BAY OF CAMPECHE AND CONTINUES INLAND FROMALONG THE MEXICAN COAST NEAR 18N94W TO EASTERN PORTIONS OF THE ISTHMUS OF TEHUANTEPEC. BROKEN TO OVERCAST MULTILAYERED CLOUD COVER BLANKET MOST OF THE GULF NW OF THE FRONT...WHERE LIGHT TO MODERATE STRATOFORM PRECIP CONTINUES TO MOVE NE ACROSS THE BASIN. SATELLITE IMAGERY SUGGESTS ISOLATED MODERATE CONVECTION OCCURRING ALONG THE FRONT ACROSS CENTRAL AND SW SECTIONS. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM THE EXTREME NW BAHAMAS SW THROUGH THE STRAITS OF FLORIDA TO THE YUCATAN CHANNEL...WHERE ABUNDANT LOW LEVEL MOISTURE IS CONVERGING BOTH E AND W OF TROUGH. SCATTERED STRONG CONVECTION CONTINUES TO FIRE ALONG AND E OF THE TROUGH FROM THE FLORIDA KEYS S-SW ACROSS W CUBA AND INTO THE NW CARIBBEAN. OUTSIDE OF THE STRONG NORTHERLY WINDS S OF 26N MENTIONED ABOVE...N TO N-NE WINDS OF 15-20 KT GENERALLY PREVAIL BEHIND THE FRONT AND N OF 26N. SEAS ARE BUILDING QUICKLY BEHIND THE FRONT...WHERE BUOY 42055 IN THE SW GULF HAS ALREADY REACHED 15 FT. THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF GENTLE TO MODERATE NORTH TO NORTHEAST WINDS PRECEDING THE COLD FRONT. THE FRONT IS FORECAST TO MOVE SOUTHEAST THROUGH TONIGHT AND STALL FROM EXTREME SOUTH FLORIDA ACROSS NW PORTIONS OF THE STRAITS OF FLORIDA AND THROUGH THE W YUCATAN CHANNEL...WHERE IT WILL LIKELY MEANDER THROUGH SATURDAY. WINDS AND SEAS WILL SUBSIDE CONSIDERABLY ACROSS SW PORTIONS OF THE GULF TONIGHT THROUGH FRIDAY...WHILE NE WINDS 20-25 KT ARE EXPECTED TO PERSIST BEHIND THE STALLED FRONT FOR SOME 200-240 NM TO THE NW THROUGH SAT. CARIBBEAN SEA... A TUTT LOW LINGERS OVER THE WINDWARD PASSAGE AND WESTERN HISPANIOLA NEAR 19N73W...AND IS BEGINNING TO DRIFT EASTWARD AS THE LONG WAVE TROUGH ACROSS THE NE AND CENTRAL U.S. CONTINUES TO TO SHIFT E AND SE. THE ASSOCIATED DYNAMICAL LIFT CREATED BY THISLOW IS COMBINING WITH LOW LEVEL MOISTURE ACROSS HISPANIOLA AND THE SURROUNDING WATERS TO PRODUCE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ALL ALONG THE SRN COASTS OF HISPANIOLA WITH DYING OVERNIGHT CONVECTION ACROSS MUCH OF INTERIOR DOMINICAN REPUBLIC. TO THE WEST...SHARP UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY AND PROVIDING DIVERGENCE ALOFT TO ENHANCE SCATTERED TO NUMEROUS SHOWERS AND TSTMS ALONG AND WITHIN 180 NM E OF A LINGERING SURFACE TROUGH ANALYZED FROM 21N85W TO 16N88W AND THE GULF OF HONDURAS. MORNING SCATTEROMETER DATA SHOWS FRESH TO STRONG EASTERLY TRADEWINDS PREVAILING ACROSS CENTRAL PORTIONS OF THEBASIN...WITH MODEL GUIDANCE INDICATING THESE TRADES BETWEEN 64W AND 77W. A STRONG ATLANTIC RIDGE PROMOTING THESE TRADES WILLSHIFT E-NE DURING THE NEXT 36-48 HOURS WITH THE WEAKENING PRESSURE GRADIENT SUPPORTING A MODEST DECREASE IN THE TRADES FRI THROUGH SAT. ...HISPANIOLA... THE TUTT LOW OVER THE WINDWARD PASSAGE AND WESTERN HISPANIOLA HAS WEAKEN SLIGHTLY OVERNIGHT...BUT CONTINUES TO SUPPORT WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ALL ALONG THE SRN COASTS OF HISPANIOLA WITH DYING OVERNIGHT CONVECTION ACROSS MUCH OF INTERIOR DOMINICAN REPUBLIC. THE TUTT LOW WILL SHIFT SLOWLY E TODAY TO MAINTAIN UNSTABLE CONDITIONS BEFORE STABILIZING CONDITIONS BEGIN TO AFFECT HAITI TONIGHT. AMPLE MOISTURE EMBEDDED IN THE E-SE LOW LEVEL FLOW WILL FOCUS DIURNAL CONVECTION ACROSS PREFERRED REGIONS OF INTERIOR AND N CENTRAL HISPANIOLA THIS AFTERNOON AND EVENING...WITH NOCTURNAL SHOWERS AND ISOLATED TSTORMS TONIGHT ALONG EASTERN COASTAL PORTIONS. ATLANTIC OCEAN... MOIST SOUTHWESTERLY FLOW ALOFT PREVAILS OVER NW PORTIONS OF THE SW NORTH ATLC WITH A COLD FRONT ANALYZED ENTERING THE AREA NEAR 31N76.5W TO CENTRAL FLORIDA JUST N OF CAPE CANAVERAL. LOW-LEVEL MOISTURE SOUTHEAST OF THE FRONT IS CONVERGING ALONG A SURFACE TROUGH FROM 31N76W TO 25.5N80W THEN THROUGH THE STRAITS OF FLORIDA...WHERE SCATTERED MODERATE TO STRONG CONVECTION IS OCCURRING ALONG AND UP TO 90 NM SE OF THE TROUGH. THE FRONT WILL CONTINUE TO SHIFT E-SE THROUGH FRI...REACHING FROM NEAR BERMUDA TO PALM BEACH FLORIDA TONIGHT...WHERE W PORTIONS OF THE FRONT WILL STALL THROUGH SAT. CONDITIONS ACROSS THE FAR WESTERN SW NORTH ATLC WATERS NEAR THE FRONT WILL REMAIN UNSTABLE UNTIL FRONTAL PASSAGE BY FRIDAY MORNING. A BROAD HIGH PRESSURE RIDGE PREVAILS SE OF THE FRONT...ANCHORED ON A 1037MB HIGH NEAR 38N36W. THE RIDGE WILL SHIFT E-NE AND WEAKEN THROUGH SAT ASTHEFRONT CONTINUES MOVING EWD AT MID LATITUDES. THEN THROUGH THE WEEKEND THE FRONT WILL BECOME MORE EAST-WEST ORIENTED AND BECOME QUASISTATIONARY FROM ALONG 29N/30N TO THE NW BAHAMAS AND EXTREME S FLORIDA...WITH STRONG TO NEAR GALE NE WINDS ARE EXPECTED DUE TO A STRENGTHENED PRESSURE GRADIENT GENERALLY N OF 27N W OF 67W. FARTHER SE...THE TUTT LOW OVER WESTERN HISPANIOLA SUPPORTS A WEAK SURFACE FROM 22N71.5W TO THE WINDWARD PASSAGE. CONVECTIONACROSS HISPANIOLA AND THE ADJACENT ATLANTIC WATERS OVERNIGHT AND THIS MORNING WAS ASSOCIATED WITH MOISTURE ACCOMPANYING THIS TROUGH. THE TROUGH WILL BECOME DIFFUSE TODAY AS IT MOVES INTO THE W PERIPHERY OF THE ATLANTIC RIDGE. OTHERWISE...THE REMAINING SIGNIFICANT FEATURE ACROSS THE EASTERN AND CENTRAL ATLC IS A COLD FRONT ANALYZED WITHIN THE SOUTHERN PERIPHERY OF A RIDGE FROM 32N24W SW TO 25N40W BECOMING STATIONARY AND WEAKENING TO 23N46W. SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT E OF 35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ STRIPLING