000 AXNT20 KNHC 282341 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI MAR 28 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 2245 UTC. ...SPECIAL FEATURES... ...CARIBBEAN SEA GALE WARNING... A TIGHT PRESSURE GRADIENT IS FOUND OVER THE SOUTH CENTRAL CARIBBEAN SEA BETWEEN A RIDGE EXTENDING FROM STRONG 1036 MB HIGH PRESSURE CENTERED IN THE CENTRAL ATLC NEAR 36N57W TO THE GULF OF HONDURAS AND LOWER PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN CONTINENT. GALE FORCE WINDS ARE CURRENTLY FOUND ALONG THE COAST OF COLOMBIA AS A RESULT OF THIS TIGHT PRESSURE GRADIENT. WINDS HERE ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY SATURDAY AFTERNOON. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ATLANTIC OCEAN GALE WARNING... PLEASE REFER TO THE METEO-FRANCE HIGH SEAS FORECAST THAT IS LISTED UNDER GRAND LARGE METAREA 2 FOR THE SECTIONS THAT ARE TITLED...MADEIRA AND AGADIR. GALE CONDITIONS CAN BE FOUND IN THOSE AREAS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES OFF THE COAST OF AFRICA NEAR 07N11W AND CONTINUES SOUTHWEST TO THE EQUATOR NEAR 21W. NO SIGNIFICANT CONVECTION CAN BE FOUND NEAR THE MONSOON TROUGH. ...DISCUSSION... GULF OF MEXICO... DIFFLUENT FLOW ALOFT OVER THE NORTHEAST GULF OF MEXICO IS ENHANCING THUNDERSTORM ACTIVITY. LAND-BASED RADARS WERE USED TO ANALYZE A SQUALL LINE ACROSS THE FLORIDA PANHANDLE ALONG 85.5W AND INTO THE GULF NEAR 29N86W. FRESH TO STRONG SOUTHERLY WINDS OVER THE SOUTHEASTERN GULF ARE FEEDING MOISTURE INTO THIS AREA OF THUNDERSTORMS. THE PATTERN SHOULD CHANGE LITTLE HERE UNTIL MIDDAY SATURDAY WHEN A COLD FRONT WILL SWING THROUGH THE AREA. THIS COLD FRONT WILL MOVE INTO THE NW GULF OVERNIGHT TONIGHT...BUT WINDS W OF THE FRONT ARE NOT EXPECTED TO INCREASE TO A FRESH TO STRONG BREEZE UNTIL SAT EVENING WHEN THE UPPER TROUGH SUPPORTING THE FRONT IS FORECAST TO AMPLIFY AS IT PASSES N OF THE GULF OF MEXICO. THE FRONT WILL REACH FROM THE FLORIDA BIG BEND TO THE YUCATAN PENINSULA LATE SAT AND PASS SE OF THE AREA ON SUN. HIGH PRESSURE AND DRIER CONDITONS WILL MOVE IN BEHIND THE FRONT. CARIBBEAN SEA... WEST TO NORTHWESTERLY FLOW ALOFT IS OVER THE CARIBBEAN BASIN WITH WATER VAPOR IMAGERY INDICATING RELATIVELY DRY AIR AND A SUBSIDENT ENVIRONMENT IN PLACE SOUTH OF 15N...WITH LINGERING MOISTURE N OF 15N ASSOCIATED WITH A WEAKENING MID-LEVEL CONVERGENCE ZONE STRETCHED FROM THE CENTRAL ATLC INTO THE NW CARIBBEAN. THERE IS NO SIGNIFICANT DEEP CONVECTION NOTED OVER THE CARIBBEAN AND ONLY ISOLATED SHOWERS FOUND MAINLY IN THE FAR EASTERN CARIBBEAN AND FROM 17N-21N WEST OF JAMAICA TO 85W. FARTHER SOUTH...A GALE WARNING IN EFFECT THROUGH SATURDAY MORNING FOR THE SOUTHERN CARIBBEAN WATERS OFF THE COAST OF COLOMBIA. SEE THE SPECIAL FEATURES SECTION ABOVE FOR DETAILS. THE STRONG PRESSURE GRADIENT BETWEEN THE AFOREMENTIONED SURFACE RIDGE OVER THE NW CARIBBEAN AND LOWER PRESSURE OVER NORTHWESTERN SOUTH AMERICA IS ALSO DRIVING FRESH TO STRONG TRADE WINDS OVER THE REMAINDER OF THE CENTRAL CARIBBEAN INCLUDING THE WINDWARD PASSAGE. LOOK FOR THESE WINDS TO DIMINISH AS THE RIDGE WEAKENS AHEAD OF A COLD FRONT FORECAST TO MOVE INTO THE NW CARIBBEAN SUN AFTERNOON. THE CHANCE OF PRECIPITATION IN THE NORTHWEST CARIBBEAN IS EXPECTED TO INCREASE BEGINNING SATURDAY NIGHT AHEAD OF THE FRONT. ...HISPANIOLA... CURRENTLY...ISOLATED SHOWERS ARE PRIMARILY FOUND OVER THE NORTHERN PORTION OF HAITI AND ON THE SOUTHEASTERN SLOPES OF THE HIGHEST TERRAIN IN THE CENTRAL DOMINICAN REPUBLIC. THESE SHOWERS CONTINUE TO BE FUELED BY MOISTURE ASSOCIATED WITH A WEAKENING MID-LEVEL CONVERGENCE ZONE STRETCHED FROM THE CENTRAL ATLC INTO THE NW CARIBBEAN. ISOLATED SHOWERS ARE FORECAST TO CONTINUE SATURDAY BUT ARE EXPECTED SHIFT EAST OF THE AREA ON SUNDAY AS MOISTURE POOLS EASTWARD AHEAD OF THE COLD FRONT FORECAST TO MOVE INTO THE NW CARIBBEAN SEA. ATLANTIC OCEAN... THE UPPER PATTERN OVER THE ATLC FEATURES WEAK TROUGHING EXTENDING FROM JUST EAST OF BERMUDA TO JUST NORTHEAST OF THE CENTRAL BAHAMAS AND A BROADER WEAK TROUGH CENTERED ALONG 52W. THESE TROUGHS ARE EXPECTED TO MERGE SATURDAY...PRODUCING A MORE AMPLIFIED PATTERN FEATURING RIDGING FROM THE BAHAMAS TO BERMUDA AND A DEEPENING UPPER TROUGH PASSING NORTHEAST OF THE NORTHEASTERN CARIBBEAN. BY SUNDAY...TROUGHING OVER THE EASTERN SEABOARD OF THE U.S. ASSOCIATED WITH THE COLD FRONT DISCUSSED IN THE GULF OF MEXICO SECTION WILL SHIFT THE RIDGE AND TROUGH UPSTREAM FARTHER TO THE EAST. AT THE SURFACE...A WEAKENING COLD FRONT EXTENDS FROM 32N40W TO 25N55W WHERE IT BECOMES STATIONARY TO NEAR 20N70W. THIS FRONT WILL DISSIPATE OVER THE NEXT DAY OR SO AND A NEW COLD FRONT WILL MOVE OFF THE U.S. EAST COAST LATE SATURDAY NIGHT...WITH FRESH TO STRONG WINDS EXPECTED ON EITHER SIDE OF THE FRONT NORTH OF 27N. UPPER DIFFLUENCE ASSOCIATED WITH A SHORTWAVE SYSTEM IN ADVANCE OF THE UPPER TROUGH MAKING ITS WAY TO THE U.S. EASTERN SEABOARD WILL ENHANCE SHOWER AND THUNDERSTORM ACTIVITY WELL AHEAD OF THE COLD FRONT. SOUTHEASTERLY FLOW IS ALREADY IN PLACE IN THE SW NORTH ATLC AND IS TRANSPORTING MOISTURE INTO THE REGION OF EXPECTED ENHANCED VERTICAL MOTION. FARTHER EAST...A SHARP UPPER TROUGH EXTENDING ALONG THE NORTHWEST COAST OF AFRICA IS ASSOCIATED WITH A COLD FRONT AT THE SURFACE AND GALE FORCE WINDS NEAR MADEIRA AND THE CANARY ISLANDS. THIS GALE EVENT IS DISCUSSED IN THE SPECIAL FEATURES SECTION ABOVE. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF THE SURFACE RIDGE THAT EXTENDS FROM THE AFOREMENTIONED 1036 MB HIGH CENTER NORTH OF THE AREA TO THE CAPE VERDE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER