000 AXNT20 KNHC 122338 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAR 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2230 UTC. ...SPECIAL FEATURES... A COLD FRONT EXTENDS FROM 30N91W NEAR NEW ORLEANS LOUISIANA SW TO 24N98W NEAR LA PESCA MEXICO. STRONG TO NEAR GALE FORCE NORTHERLY WINDS WITH FREQUENT GUSTS TO GALE FORCE CAN BE FOUND WEST OF THE FRONT. THE FRONT IS FORECAST TO SWEEP SOUTHWARD ALONG THE MEXICAN COAST. GALES WILL DIMINISH IN THE NW GULF THIS EVENING AND SHIFT TO ALONG THE COAST OF VERACRUZ THROUGH EARLY THU MORNING. AT THE SAME TIME...THE FRONT WILL MOVE INTO THE SW NORTH ATLC WITH GALE FORCE NW WINDS BEHIND THE FRONT. GALE CONDITIONS WILL DIMINISH AS THE FRONT MOVES TO 31N72W TO 23N80W NEAR NORTHERN CUBA JUST AFTER SUNRISE THU. SEE THE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 06N11W TO 03N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N14W TO THE EQUATOR AT 21W. ISOLATED MODERATE CONVECTION IS SOUTH OF 04N BETWEEN 12W-18W. SCATTERED MODERATE IS SOUTH OF 01N BETWEEN 23W AND 27W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY FROM THE NORTH CAROLINA COAST TO THE NORTHERN BAHAMAS. THIS TROUGH IS RAPIDLY MOVING NE AHEAD OF A BROAD TROUGH AMPLIFYING OVER THE MISSISSIPPI VALLEY. AT THE SURFACE...THE SHORTWAVE SYSTEM IS FORCING A TROUGH THAT EXTENDS OVER THE FORECAST AREA FROM NEAR JACKSONVILLE FLORIDA TO JUST NORTH OF THE YUCATAN PENINSULA NEAR 23N88W. MEANWHILE...THE BROAD TROUGH ALOFT IS REFLECTING A STRONG SURFACE COLD FRONT THAT HAS BROUGHT GALE CONDITIONS TO THE NW GULF OF MEXICO. PLEASE SEE THE SPECIAL FEATURES SECTION FOR DETAILS CONCERNING THE GALE CONDITONS. PRECIPITABLE WATER IMAGERY SHOWS THAT MOISTURE IS CONVERGED AHEAD OF THE SURFACE TROUGH...LEAVING RELATIVELY DRY CONDITONS TO THE WEST NEAR THE COLD FRONT. RADAR IMAGERY SHOWS A LINE OF SHOWERS OVER CENTRAL FLORIDA FROM 26N-29N AHEAD OF THE TROUGH...WITH LIGHTNING FOUND WITHIN 75 NM SE OF THE TAIL OF THE TROUGH NORTH OF THE YUCATAN CHANNEL. IN THE FORECAST PERIOD...THE BROAD UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL OVERTAKE THE SHORTWAVE SYSTEM AND ITS ASSOCIATED SURFACE TROUGH OVERNIGHT TONIGHT. AS THE FRONT SWEEPS SOUTHEASTWARD THROUGH THURSDAY...N-NE WINDS ARE FORECAST TO REMAIN IN THE 20 TO 30 KT RANGE...GRADUALLY DIMINISHING LATE THURSDAY INTO FRIDAY AS HIGH PRESSURE BUILDS INTO THE BASIN FROM THE SOUTHERN PLAINS. THE HIGH WILL SHIFT EASTWARD ALONG 30N/31N FRIDAY INTO SATURDAY WITH SOUTHERLY RETURN FLOW ESTABLISHING ITSELF ACROSS PORTIONS OF THE WESTERN GULF. CARIBBEAN SEA... CONDITIONS ACROSS THE CARIBBEAN REMAIN RELATIVELY TRANQUIL. WATER VAPOR IMAGERY SHOWS VERY DRY AIR ALOFT IMPLYING SUBSIDENT CONDITONS OVER THE BASIN. AN UPPER LEVEL RIDGE FROM NE VENEZUELA TO NICARAGUA WILL REMAIN IN PLACE THROUGH FRI. ISOLATED TRADE WIND SHOWERS CAN BE FOUND IN MUCH OF THE AREA...WITH MORE SCATTERED SHOWERS FOUND IN THE FAR EASTERN CARIBBEAN FROM 13N- 16N EAST OF 66W TO THE ISLANDS AND IN THE SW CARIBBEAN FROM 10N- 15N BETWEEN 79W AND 82W. WINDS AT THE SURFACE ARE RELATIVELY WEAK ACROSS THE CARIBBEAN ON THE SOUTHWESTERN PERIPHERY OF A SURFACE RIDGE STEMMING FROM HIGH PRES IN THE CENTRAL ATLC. THE RIDGING TO THE NORTHEAST OF THE BASIN IS FORECAST TO SHIFT E-NE AHEAD OF A COLD FRONT THAT WILL MOVE INTO THE NW CARIBBEAN EARLY THURSDAY. MOISTURE IS CURRENTLY POOLED AHEAD OF A PRE-FRONTAL TROUGH FOUND JUST NORTH OF THE YUCATAN CHANNEL. SCATTERED THUNDERSTORMS CURRENTLY ACCOMPANYING THIS TROUGH SHOULD MOVE INTO THE NORTHWEST CARIBBEAN OVERNIGHT TONIGHT AND ARE EXPECTED NEAR THE FRONT AS IT MOVES INTO THE NORTHWEST CARIBBEAN. THE FRONT WILL REACH FROM NEAR HAVANA CUBA TO CHETUMAL MEXICO THU MORNING AND FROM MANZANILLO CUBA TO BELIZE CITY FRI MORNING. OTHERWISE...FAIR WEATHER CONDITIONS SHOULD REMAIN RELATIVELY UNCHANGED FOR THE NEXT FEW DAYS. ...HISPANIOLA... SCATTERED SHOWERS ARE CLUSTERED CLOSE TO THE MOUNTAIN RANGES OVER HISPANIOLA...WITH LIGHT WINDS PREVENTING THEM FROM STRAYING FAR FROM THE AREA OF GREATEST OROGRAPHIC ENHANCEMENT. ELSEWHERE...MOSTLY CLEAR SKIES AND FAIR CONDITIONS ARE NOTED ON VISIBLE SATELLITE IMAGERY. THE HIGH PRESSURE OVER THE CENTRAL ATLC THAT IS PRODUCING THE LIGHT E-SE WINDS WILL SLIDE EAST THROUGH EARLY THU AS A FRONTAL BOUNDARY MOVES ACROSS THE SW NORTH ATLC AND NW CARIBBEAN WATERS. THE FRONT WILL BEGIN TO IMPACT HISPANIOLA FRI AS MOISTURE POOLED AHEAD OF THE FRONT BEGINS TO INCREASE THE PROBABILITY OF PRECIPITATION. THE FRONT IS EXPECTED TO WEAKEN AS IT REACHES THE WINDWARD PASSAGE FRI EVENING. ATLANTIC OCEAN... THE AFOREMENTIONED SHORTWAVE TROUGH STRETCHING FROM THE NORTH CAROLINA COAST TO THE NORTHERN BAHAMAS IS PROVIDING INSTABILITY TO THE MOISTURE POOLED AHEAD OF ITS ASSOCIATED SURFACE TROUGH WHICH IS STRETCHED FROM JACKSONVILLE TO FORT MYERS FLORIDA. SCATTERED THUNDERSTORMS ARE NOTED PRIMARILY NORTH OF 29N BETWEEN 75W AND 78W. IN THE FORECAST PERIOD...THE BROAD UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL OVERTAKE THE SHORTWAVE SYSTEM AND ITS ASSOCIATED SURFACE TROUGH OVERNIGHT TONIGHT. SEE THE SPECIAL FEATURES SECTION FOR DETAILS ON THE GALE CONDITONS EXPECTED BEHIND THE COLD FRONT NORTH OF 30N ENDING AROUND SUNRISE THU. THE FRONT WILL CONTINUE EASTWARD...STRETCHING FROM BERMUDA TO THE CENTRAL BAHAMAS THU EVENING AND FROM 32N55W TO THE WINDWARD PASSAGE BY FRI EVENING. SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONT. TO THE EAST...AN UPPER LEVEL LOW NORTH OF THE AREA NEAR 40N35W EXTENDS A TROUGH INTO THE CENTRAL PORTION OF THE FORECAST AREA AND REFLECTS A COLD FRONT AT THE SURFACE FROM 32N33W TO 27N40W THEN BECOMING A STATIONARY FRONT TO 20N56W. WIDELY SCATTERED SHOWERS ARE OCCURRING WITHIN 150 NM SOUTHEAST OF THE FRONT...WITH SHOWERS BECOMING MORE NUMEROUS EAST OF 40W WHERE THE FRONT BECOMES A COLD FRONT. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE CURRENTLY STEMMING FROM 1021 MB HIGH PRES CENTERED NEAR 31N48W. THIS RIDGE IS BISECTED BY THE FRONT OVER THE CENTRAL ATLC. THIS FRONT IS EXPECTED TO WEAKEN AND SHIFT NORTH OF THE AREA OVER THE NEXT TWO DAYS. THE REMAINING RIDGE WILL DRIVE MODERATE TRADE WINDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER