000 AXNT20 KNHC 210553 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST FRI FEB 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A STRONG PRESSURE GRADIENT BETWEEN A BROAD SURFACE RIDGE OVER THE NORTH ATLC EXTENDING INTO THE CARIBBEAN AND LOWER PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN CONTINENT IS GENERATING GALE FORCE NE WINDS IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA FROM 11N TO 13N BETWEEN 74W AND 76W WITH SEAS FROM 10 TO 15 FT. THESE WEATHER CONDITIONS ARE FORECAST THROUGH FRI NIGHT. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 10N14W AND CONTINUES TO 6N16W TO 3N20W. THE ITCZ BEGINS NEAR 3N20W AND CONTINUES TO 1N26W TO 1S32W. SCATTERED MODERATE CONVECTION IS FROM 2S-3N BETWEEN 20W-38W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS ACROSS CENTRAL U.S. AND BASE OVER THE NW GULF SUPPORTS A FRONTAL SYSTEM THAT ENTERS AS A COLD FRONT FROM SW LOUISIANA NEAR 29N93W TO CORPUS CHRISTI TEXAS. THE TROUGH ALOFT ALSO SUPPORTS A PRE-FRONTAL TROUGH FROM 29N92W TO BROWNSVILLE TEXAS. SSMI TPW IMAGERY SHOW MOISTURE ADVECTION FROM THE CARIBBEAN REACHING THE N-NW GULF COAST. A DEEP LAYER RIDGE WITH AXIS ALONG THE EASTERN U.S. COASTLINE IS GENERATING DIFFLUENCE ALOFT WHICH ALONG LOW-LEVEL MOISTURE CONVERGENCE SUPPORT A SWATH OF HEAVY SHOWERS AND TSTMS FROM THE LOWER GREAT LAKES SW TO THE LOWER MISSISSIPPI VALLEY AND INTO THE GULF N OF 27N BETWEEN 90W-95W. WATER VAPOR IMAGERY SHOW MOSTLY DRY AIR IN THE MIDDLE LEVELS ACROSS THE REMAINDER GULF WITH SOME UPPER LEVEL MOISTURE BEING ADVECTED FROM THE E PACIFIC INTO THE WESTERN GULF BY WESTERLY FLOW. SURFACE RIDGING CONTINUE TO EXTEND FROM THE ATLC INTO THE EASTERN GULF THUS PROVIDING RETURN FLOW OF 15 KT ACROSS THE ENTIRE BASIN WITH HIGHER WINDS UP TO 20 KT IN CLOSE PROXIMITY OF THE FRONT. THE FRONT WILL CONTINUE TO MOVE SE TO EXTEND FROM TALLAHASSEE FLORIDA SW TO THE BAY OF CAMPECHE BY FRIDAY MORNING. THE FRONT IS EXPECTED TO STALL ACROSS NORTHERN FLORIDA AND THE EASTERN GULF FRI NIGHT AND WILL START DISSIPATING BY SAT MORNING. CARIBBEAN SEA... NW TO W WIND FLOW ALOFT FROM THE NW TO EASTERN CARIBBEAN THIS MORNING WITH WATER VAPOR IMAGERY INDICATING DRY AIR SUBSIDENCE ACROSS THE ENTIRE BASIN. THIS DRY AIR SUPPORTS MOSTLY FAIR WEATHER BASIN WIDE. HOWEVER...PASSING SHOWERS ARE EXPECTED TONIGHT FOR PUERTO RICO AND THE VIRGIN ISLANDS ASSOCIATED WITH A WESTWARD MOVING MOIST AIRMASS JUST NE OF THE LEEWARD ISLANDS. IN TERMS OF WIND...EASTERLY TRADES OF 20 KT DOMINATE ACROSS THE BASIN EXCEPT FOR THE CENTRAL CARIBBEAN WHERE WINDS ARE UP TO 25 KT WITH GALE FORCE WINDS ALONG THE COAST OF COLOMBIA. GALE FORCE WINDS FOR THE ABOVE MENTIONED REGION ARE EXPECTED TO CONTINUE THROUGH FRI NIGHT. SEE SPECIAL FEATURES SECTION FOR MORE DETAILS. ...HISPANIOLA... CURRENTLY FAIR WEATHER CONDITIONS ON THE ISLAND BEING SUPPORTED BY DRY AIR AT THE LOWER LEVELS AND ALOFT. MODEL GUIDANCE INDICATE SIMILAR CONDITIONS TO PREVAIL THROUGH EARLY FRIDAY. A MOIST AIRMASS IS EXPECTED TO ENTER THE ISLAND LATE FRIDAY MORNING WHICH MAY ENHANCE SHALLOW CONVECTION. SKIES MAY CLEAR OUT AGAIN SAT MORNING WITH THE ADVENT OF A LOWER LEVEL DRY AIRMASS. ATLANTIC OCEAN... A WEAK SURFACE PRE-FRONTAL TROUGH EXTENDS FROM 31N58W TO 27N61W. DIFFLUENCE ALOFT IS ENHANCING ISOLATED SHOWERS EAST OF THE TROUGH N OF 21N BETWEEN 51W-62W. OTHERWISE...A BROAD SURFACE RIDGE DOMINATES THE ENTIRE ATLC WATERS ANCHORED BY TWO HIGH PRESSURE CENTERS...A 1028 MB HIGH NEAR 32N65W AND A 1036 MB HIGH NEAR 37N29W. A WEAK COLD FRONT IS FORECAST TO ENTER THE SW N ATLC SAT MORNING WHICH THEN WILL TRANSITION TO A STATIONARY FRONT THROUGH SUN MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR