000 AXNT20 KNHC 040001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU DEC 3 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... A COLD FRONT EXTENDS FROM CENTRAL FLORIDA TO THE BAY OF CAMPECHE AND CONTINUES INLAND ACROSS THE ISTHMUS OF TEHUANTEPEC. A STRONG PRESSURE GRADIENT BETWEEN THE FRONT AND 1030 MB HIGH PRESSURE IN NE MEXICO IS GENERATING GALE FORCE N-NW WINDS S OF 21N W OF 94W. 20-30 KT NORTHERLY WINDS PREVAIL ELSEWHERE W OF THE FRONT S OF 26N. THE AREA OF GALES IS EXPECTED TO SHIFT SLOWLY SOUTHWARD THE REST OF TONIGHT. SEE THE LATEST FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THERE IS NO MONSOON TROUGH PRESENT ACROSS THE W AFRICAN REGION. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM SIERRA LEONE NEAR 08N13W TO 05N37W TO 07N48W TO THE COAST OF SURINAME NEAR 06N57W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 32W-44W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS UPPER TROUGH EXTENDS OVER THE MID-MISSISSIPPI RIVER VALLEY AND SOUTHERN PLAINS TO NORTHERN MEXICO THEN S OF BAJA CALIFORNIA. THE TROUGH IS SUPPORTING A COLD FRONT EXTENDING FROM CENTRAL FLORIDA TO THE BAY OF CAMPECHE. BROKEN TO OVERCAST MULTILAYERED CLOUDS BLANKET A LARGE PORTION 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. 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. N TO N-NE WINDS OF 15-20 KT GENERALLY PREVAIL BEHIND THE FRONT N OF 26N. SEAS ARE BUILDING QUICKLY BEHIND THE FRONT. MODERATE NORTH TO NORTHEAST WINDS PRECEDE THE COLD FRONT. THE FRONT WILL MOVE SOUTHEAST THROUGH TONIGHT THEN STALL FROM THE FLORIDA KEYS TO THE 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 200-250 NM N OF THE STALLED FRONT THROUGH SAT. CARIBBEAN SEA... A TUTT LOW LINGERS OVER THE WINDWARD PASSAGE AND HAITI NEAR 19N73W...AND IS BEGINNING TO DRIFT EASTWARD AS THE LONG WAVE TROUGH ACROSS THE CENTRAL U.S. SHIFTS E. THE LOW IS ENHANCING WIDELY SCATTERED SHOWERS NEAR HISPANIOLA. SHARP UPPER LEVEL RIDGING TO THE WEST IS NOTED ON WATER VAPOR IMAGERY TO ENHANCE SCATTERED TO NUMEROUS SHOWERS AND TSTMS ALONG AND WITHIN 180 NM E OF A LINGERING SURFACE TROUGH ACROSS THE NW CARIBBEAN AND THE GULF OF HONDURAS. SCATTEROMETER DATA SHOWS FRESH TO STRONG E TRADES IN THE CENTRAL PORTION OF THE BASIN. A STRONG ATLANTIC RIDGE PROMOTING THESE TRADES WILL SHIFT 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 WEAKENED SLIGHTLY...BUT STILL SUPPORTS WIDELY SCATTERED SHOWERS OVER HISPANIOLA. THE TUTT LOW WILL SHIFT SLOWLY E TODAY TO MAINTAIN UNSTABLE BUT IMPROVING CONDITIONS TONIGHT. AMPLE MOISTURE EMBEDDED IN THE E-SE LOW LEVEL FLOW WILL FOCUS DIURNAL CONVECTION ACROSS PREFERRED REGIONS OF INTERIOR AND N CENTRAL HISPANIOLA DURING THE DAY...WITH NOCTURNAL SHOWERS AND ISOLATED TSTORMS TONIGHT ALONG EASTERN COASTAL PORTIONS. ATLANTIC OCEAN... A COLD FRONT EXTENDS FROM 31N75W TO CENTRAL FLORIDA. CONVERGENT LOW-LEVEL MOISTURE SE OF THE FRONT PRODUCING SCATTERED MODERATE CONVECTION UP TO 150 NM AHEAD OF THE FRONTAL BOUNDARY. THE FRONT WILL CONTINUE TO SHIFT E-SE THROUGH FRI...REACHING FROM NEAR BERMUDA TO PALM BEACH FLORIDA LATER TONIGHT...THEN STALL FROM 31N65W TO THE FLORIDA KEYS THROUGH SAT. THE SUBTROPICAL RIDGE WILL SHIFT E-NE AND WEAKEN THROUGH SAT AS THE FRONT CONTINUES MOVING EWD AT MID LATITUDES. CONDITIONS ACROSS THE FAR WESTERN SW NORTH ATLC WATERS NEAR THE FRONT WILL REMAIN UNSTABLE UNTIL FRONTAL PASSAGE FRI MORNING. 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 EXPECTED AS THE PRESSURE GRADIENT STRENGTHENS N OF 27N W OF 67W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MUNDELL