000 AXNT20 KNHC 160000 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAR 15 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 FEATURE... GALE-FORCE WINDS ARE FORECAST IN THE GULF OF MEXICO STARTING SUN NIGHT THROUGH MON NIGHT ASSOCIATED WITH A COLD FRONT. THROUGHOUT THIS PERIOD SEAS ARE EXPECTED TO INCREASE FROM 9 FT TO 12 FT. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT4/FZNT24 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 7N11W AND CONTINUES SW TO 2N21W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 0N30W TO 0N37W. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS FROM 1N-4N BETWEEN 21W-26W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 2S-7N BETWEEN 18W-27W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY DEPICT SOUTHWESTERLY-WESTERLY FLOW ALOFT ADVECTING MODERATE MOISTURE FROM THE E PAC TO THE NORTHERN BASIN N OF 27N WHILE DRY AIR SUBSIDENCE PREVAILS ACROSS THE REMAINDER GULF SUPPORTING FAIR WEATHER. AT THE SURFACE...AN ELONGATED RIDGE ANCHORED BY A 1025 MB HIGH NEAR 42N55W AND A 1025 MB HIGH NEAR 33N64W EXTENDS INTO THE GULF AND CONTINUES TO PROVIDE SOUTHEASTERLY WIND FLOW OF 10-15 KT WITH A MAX OF 20 KT IN THE NW BASIN. RETURN FLOW CONTINUE TO ADVECT LOW LEVEL MOISTURE FROM THE NW CARIBBEAN INTO THE WESTERN AND CENTRAL GULF WHICH IS SUPPORTING BROKEN TO OVERCAST SKIES N OF 26N W OF 87W AND FOG N OF 27N W OF 91W. RIDGING AND RETURN FLOW UP TO 20 KT IS FORECAST TO DOMINATE ACROSS THE GULF THROUGH SUN MORNING. A SURFACE LOW PRESSURE CENTER WITH ASSOCIATED TROUGH IS EXPECTED TO DEVELOP OVER THE FAR WESTERN BASIN AHEAD OF A COLD FRONT TO ENTER THE NW GULF EARLY SUNDAY AFTERNOON. ASSOCIATED GALE FORCE WINDS ARE FORECAST TO DEVELOP SUNDAY NIGHT ACROSS THE WESTERN BASIN. SEE THE SPECIAL FEATURES ABOVE FOR MORE DETAILS. CARIBBEAN SEA... THE TAIL OF A FRONTAL SYSTEM OVER THE CENTRAL ATLC EXTENDS ACROSS HISPANIOLA AS A STATIONARY FRONT AND SUPPORTS BROKEN SKIES WITH POSSIBLE SCATTERED SHOWERS AND TSTMS MAINLY OVER THE DOMINICAN REPUBLIC. OVER THE NW BASIN...LINGERING LOW-LEVEL MOISTURE ASSOCIATED WITH THE PASSAGE OF THE AFOREMENTIONED FRONT ENHANCES SHOWERS ACROSS JAMAICA. LOW-LEVEL MOISTURE CONVERGENCE AHEAD OF THE FRONT MAY ENHANCE PASSING SHOWERS ACROSS THE MONA PASSAGE AND NORTHERN PUERTO RICO. SHOWERS ARE ALSO POSSIBLE FOR THE SOUTHERN WINDWARD ISLANDS ASSOCIATED WITH A BROAD AREA OF MOISTURE APPROACHING THE REGION. ALOFT...A RIDGE DOMINATES THE BASIN WITH WATER VAPOR IMAGERY DEPICTING DRY AIR SUBSIDENCE WHICH IS PROVIDING OVERALL STABILITY. OTHERWISE...TRADES OF 10- 15 KT ARE ACROSS THE CARIBBEAN WATERS. THE FRONTAL BOUNDARY IS EXPECTED TO MOVE N OF HISPANIOLA BY SUN MORNING WHERE IT IS EXPECTED TO DISSIPATE. HISPANIOLA... THE TAIL OF A COLD FRONT OVER THE CENTRAL ATLC EXTENDS ACROSS THE ISLAND AS A STATIONARY FRONT. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE FRONTAL BOUNDARY AND ITS VICINITY SUPPORTS BROKEN SKIES AND POSSIBLE ISOLATED SHOWERS ACROSS THE ISLAND...ESPECIALLY FOR THE DOMINICAN REPUBLIC. THE FRONT IS FORECAST TO MOVE N OF THE ISLAND BY SUN MORNING...HOWEVER LINGERING MOISTURE WILL SUPPORT RAINSHOWERS THROUGH SUN NIGHT. ATLANTIC OCEAN... A DEEP LAYER TROUGH OVER THE NORTH CENTRAL ATLC SUPPORTS A COLD FRONT THAT EXTENDS INTO THE DISCUSSION AREA ALONG 30N46W SW TO 24N56W TO 21N63W WHERE IT TRANSITIONS TO A STATIONARY FRONT TO HISPANIOLA NEAR 19N70W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ASSOCIATED WITH THE FRONT ARE N OF 23N BETWEEN 43W-57W. ISOLATED SHOWERS ARE ELSEWHERE WITHIN 100 NM EITHER SIDE OF THE FRONT. OTHERWISE...SURFACE RIDGING DOMINATES THE SW N ATLC WATERS AS WELL AS THE E ATLC N OF 17N. THE COLD FRONT IS EXPECTED TO TRANSITION INTO A STATIONARY FRONT TONIGHT AND START DISSIPATING SUN MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR