000 AXNT20 KNHC 211118 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 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 73W AND 77W WITH SEAS FROM 10 TO 15 FT. THESE WEATHER CONDITIONS ARE FORECAST THROUGH SAT MORNING. 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 9N14W AND CONTINUES TO 5N16W TO 3N20W. THE ITCZ BEGINS NEAR 3N20W AND CONTINUES TO 1N31W TO 0N41W TO 0S50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 1S-3N BETWEEN 17W- 38W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM THE UPPER TO LOWER MISSISSIPPI VALLEY SUPPORTS A FRONTAL SYSTEM THAT ENTERS THE GULF AS A COLD FRONT FROM SOUTHERN MISSISSIPPI NEAR 30N89W TO SE LOUISIANA NEAR 29N90W TO 27N94W TO SOUTHERN TEXAS NEAR 26N97W. THE TROUGH ALOFT ALSO SUPPORTS A PRE-FRONTAL TROUGH FROM 31N86W TO 27N91W TO 24N96W. SSMI TPW IMAGERY SHOW MOISTURE ADVECTION FROM THE CARIBBEAN REACHING THE NORTHERN GULF COAST. A DEEP LAYER RIDGE WITH AXIS ALONG THE FAR WESTERN N ATLC IS GENERATING DIFFLUENCE ALOFT OVER THE EASTERN U.S. WHICH ALONG LOW-LEVEL MOISTURE CONVERGENCE SUPPORT A SWATH OF HEAVY SHOWERS AND TSTMS FROM THE LOWER GREAT LAKES SW TO GEORGIA AND ALABAMA INTO THE GULF N OF 26N BETWEEN 85W-90W. 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 THIS PORTION OF THE BASIN...NE WIND OF 25-30 KT IS OVER THE NW GULF EAST OF THE SURFACE TROUGH. THE FRONT WILL CONTINUE TO MOVE SE TO EXTEND FROM TALLAHASSEE FLORIDA SW TO THE BAY OF CAMPECHE LATER THIS MORNING. THE FRONT IS EXPECTED TO STALL ACROSS NORTHERN FLORIDA AND THE EASTERN GULF FRI NIGHT AND WILL START DISSIPATING BY SAT MORNING. A NEW COLD FRONT IS EXPECTED TO ENTER THE NORTHERN GULF SUN NIGHT. 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 ACROSS THE REGION. HOWEVER...SCATTERED PASSING SHOWERS ARE EXPECTED FOR PUERTO RICO...VIRGIN ISLANDS AND LEEWARD ISLANDS ASSOCIATED WITH A WESTWARD MOVING MOIST AIRMASS CURRENTLY OVER THE NE CARIBBEAN. SIMILAR CONVECTION IS FROM 11N- 16N BETWEEN 65W-83W. IN TERMS OF WIND...EASTERLY TRADES OF 20-25 KT DOMINATE ACROSS THE CENTRAL AND EASTERN BASIN WITH GALE FORCE WINDS ALONG THE COAST OF COLOMBIA. GALE FORCE WINDS FOR THE ABOVE MENTIONED REGION ARE EXPECTED TO CONTINUE THROUGH SAT MORNING. 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. HOWEVER...A MOIST AIRMASS IS EXPECTED TO ENTER THE ISLAND LATER THIS MORNING WHICH MAY ENHANCE SHALLOW CONVECTION. MODEL GUIDANCE INDICATE SKIES MAY CLEAR OUT AGAIN SAT MORNING WITH THE ADVENT OF A LOWER LEVEL DRY AIRMASS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH EXTENDING FROM THE NORTH-CENTRAL ATLC SW TO A BASE JUST NE OF THE DOMINICAN REPUBLIC SUPPORT A WEAK SURFACE PRE-FRONTAL TROUGH ALONG 33N54W TO 30N58W TO 28N62W. DIFFLUENT FLOW ALOFT SE OF THE TROUGH IS ENHANCING ISOLATED SHOWERS N OF 24N BETWEEN 52W-60W. OTHERWISE...A BROAD SURFACE RIDGE DOMINATES THE ENTIRE ATLC WATERS ANCHORED BY TWO HIGH PRESSURE CENTERS...A 1028 MB HIGH NEAR 33N63W AND A 1033 MB HIGH NEAR 36N24W. A WEAK COLD FRONT IS FORECAST TO ENTER THE SW N ATLC FRI NIGHT AND DISSIPATE SAT NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR