000 AXNT20 KNHC 270002 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAR 26 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 2345 UTC. ...SPECIAL FEATURES... A COLD FRONT ENTER THE SW NORTH ATLC REGION THROUGH 32N60W TO THE SE BAHAMAS NEAR 22N75W WITH GALE FORCE W TO NW WINDS N OF 27N WEST OF THE FRONT TO 74W AND GALE FORCE S TO SW WINDS N OF 29N EAST OF THE FRONT TO 58W. WINDS ARE FORECAST TO DROP BELOW GALE FORCE TONIGHT. SEE NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. A STRONG PRESSURE GRADIENT IS EXPECTED TO SETUP ACROSS THE SW CARIBBEAN SEA BETWEEN STRONG HIGH PRESSURE CENTERED ACROSS THE SE CONUS AND LOWER PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN CONTINENT. GALE FORCE NE TO E WINDS ARE ANTICIPATED TO COMMENCE BY 27/0600 UTC. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. A STRONG PRESSURE GRADIENT EXISTS BETWEEN HIGH PRESSURE ACROSS THE EASTERN ATLC AND LOWER PRESSURE CENTERED ACROSS INLAND NORTHWEST AFRICA THIS AFTERNOON. GALE FORCE N TO NE WINDS ARE OCCURRING FROM 29N-32N BETWEEN 10W-13W ALONG THE COAST OF MOROCCO. SEE LATEST METEO-FRANCE HIGH SEAS FORECAST UNDER WMO HEADER FQNT50 LFPW. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 01N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 01N21W TO THE EQUATOR NEAR 25W. SCATTERED MODERATE CONVECTION IS FROM 01N-04N BETWEEN 18W-25W. ...DISCUSSION... GULF OF MEXICO... FLAT BROAD MIDDLE TO UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE GULF BASIN THIS EVENING AS THE VERY DEEP UPPER LEVEL TROUGH LIFTS OUT TO THE NE OVER THE N ATLC. A MID-LEVEL SHORTWAVE TROUGH IS EMBEDDED WITHIN THE FLAT RIDGE WITH AXIS ALONG 93W N OF 28N. THIS ENERGY ALOFT IS GENERATING EXTENSIVE CLOUDINESS AND AN AREA OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE NW GULF EXTENDING NWD ALONG THE UPPER TEXAS AND LOUISIANA COASTS. THIS ACTIVITY CONTINUES TO MOVE EAST AT 20-25 KT. THIS WAS CONFIRMED BY MOSAIC DOPPLER RADAR IMAGERY AND LIGHTNING DATA. OVERCAST LOW AND MID LEVEL CLOUDS WITH EMBEDDED SHOWERS WERE NOTED ELSEWHERE N OF 21N W OF 88W...TO THE E OF A SURFACE TROUGH EXTENDING FROM 23N95W TO 19N94W. THIS AREA OF CONVECTION LIES WITHIN THE SOUTHWESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH CENTERED OVER ALABAMA. WITH THE RIDGE IN PLACE AND EXPECTED TO SLIDE EASTWARD OVER THE NEXT 24 HOURS...E-SE WINDS WILL PREVAIL IN THE RANGE OF 15 TO 25 KT WITH THE STRONGER WINDS LOCATED GENERALLY OVER WESTERN PORTIONS...W OF 90W...THROUGH EARLY THURSDAY...AND THEN SHIFT TO PORTIONS OF THE EASTERN GULF THEREAFTER THROUGH FRIDAY. TEMPERED SOUTHERLY FLOW IS FORECAST FOR FRIDAY IN ADVANCE OF THE NEXT COLD FRONT TO EMERGE OFF THE TEXAS AND LOUISIANA COAST EARLY SATURDAY. CARIBBEAN SEA... NEARLY ZONAL WESTERLY FLOW ALOFT DOMINATED THE CARIBBEAN BASIN THIS EVENING...HOWEVER THE SOUTHERLY EXTENT OF A MIDDLE TO UPPER LEVEL TROUGH DIPS SOUTHWARD TO A BROAD BASE OVER THE SW NORTH ATLC. THIS TROUGH WAS SUPPORTING A SURFACE COLD FRONT FROM THE SE BAHAMAS NEAR 22N75W TO 21N78W AND OVER CUBA. THE FRONT BECAME STATIONARY FROM THE COAST OF CUBA TO NEAR COZUMEL YUCATAN. DURING THE PAST FEW HOURS WEAKENING CONTINUES TO TAKE PLACE AND THE FRONT IS EXPECTED TO BECOME DIFFUSE TONIGHT. THE FRONT REMAINS RELATIVELY PRECIPITATION-FREE THIS EVENING WITH THE MOST SIGNIFICANT IMPACTS BEING SLIGHTLY COOLER TEMPERATURES AND DRIER AIR ALONG WITH STRONGER NE WINDS NORTH OF THE FRONT. OTHERWISE...THE REMAINDER OF THE BASIN IS EXPERIENCING TRADE WINDS IN THE RANGE OF 10 TO 20 KT WITH THE USUAL SLIGHTLY STRONGER...20 TO 25 KT WINDS EXPECTED IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. THESE WINDS ARE FORECAST TO INCREASE TO GALE FORCE FROM 11N TO 13N BETWEEN 74W AND 77W LATER TONIGHT. SKIES WILL REMAIN FAIR THROUGH THE OVERNIGHT HOURS. ...HISPANIOLA... SCATTERED TO BROKEN CLOUDS ARE INDICATED OVER HISPANIOLA WITH ISOLATED THUNDERSTORMS OVER THE INTERIOR. THE PROXIMITY OF A PRE- FRONTAL TROUGH OVER THE NW PORTION OF THE ISLAND WHICH EXTENDED NE OVER THE SW N ATLC HAS PROVIDED ENOUGH LIFT AND INSTABILITY TO TRIGGER THIS ACTIVITY. ATLANTIC OCEAN... A VIGOROUS AND NEGATIVELY-TILTED UPPER LEVEL TROUGH AND THE ASSOCIATED DEEP LAYERED CYCLONE IS NOTED ON WATER VAPOR IMAGERY CENTERED JUST S OF NOVA SCOTIA. THIS TROUGH SUPPORTS A STRONG COLD FRONT SWEEPING ACROSS THE SW NORTH ATLC THIS EVENING. THE FRONT EXTENDED FROM 32N60W THROUGH THE SE BAHAMAS TO THE COAST OF CUBA NEAR 21N77W. A PRE-FRONTAL TROUGH EXTENDED FROM 28N62W TO THE N COAST OF HISPANIOLA. MOST OF THE SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ALONG AND WITHIN 180-240 NM EAST OF THE PRE-FRONTAL TROUGH N OF 25N AND WITHIN 60-90 NM E OF THE TROUGH S OF 25N. THE STRONGEST ACTIVITY WAS CONFINED TO THE SOUTHERN EXTENT OF THE TROUGH. FARTHER EAST...A SHARP UPPER LEVEL RIDGE EXTENDED THROUGH 32N45W TO A BASE NEAR 20N55W. A DOWNSTREAM TROUGH WITH AXIS ALONG 32N14W 22N38W TO A BASE NEAR 15N54W. AT THE SURFACE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED SOUTHEAST OF THE AZORES NEAR 37N24W. 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