000 AXNT20 KNHC 071119 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI MAR 07 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 FEATURE... A GALE IS FORECAST TO BEGIN LATE FRI NIGHT OVER THE SW N ATLANTIC N OF 27N WITHIN 150 NM SE OF A COLD FRONT EXPECTED TO EXTEND FROM 31N68W TO 21N78W. GALE FORCE WINDS ARE FORECAST THROUGH LATE SATURDAY NIGHT. PLEASE SEE THE HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT01 KNHC OR THE OFFSHORE FORECAST UNDER AWIPS/WMO HEADERS MIAOFFNT3/FZNT23 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 5N9W AND CONTINUES ALONG 2N20W TO 1N30W. THE ITCZ BEGINS NEAR 1N30W AND CONTINUES TO 0S40W TO COASTAL BRAZIL NEAR 0S50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITH EMBEDDED TSTMS ARE FROM 1S-6N BETWEEN E OF 15W. SCATTERED MODERATE CONVECTION IS FROM 1S-5N BETWEEN 20W-28W. ...DISCUSSION... GULF OF MEXICO... A DEEP LAYERED TROUGH WITH AXIS OVER THE EASTERN CONUS CONTINUE TO SUPPORT A FRONTAL SYSTEM ON THE SW N ATLC ASSOCIATED WITH A 1004 MB LOW NEAR 32N76W. A COLD FRONT EXTENDS FROM THE LOW AND MOVES ACROSS CENTRAL-SOUTHERN FLORIDA TO ENTER THE STRAITS NEAR 25N81W TO NW CUBA NEAR 23N82W AND THEN INTO THE NW CARIBBEAN. DIFFLUENT WIND FLOW ALOFT IS BEING GENERATED BY A BROAD UPPER LEVEL RIDGE COVERING MOST OF THE W ATLC AND THE CARIBBEAN TO ENHANCE PASSING SHOWERS ACROSS THE FLORIDA STRAITS. A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH ON THE BORDER OF ARKANSAS AND LOUISIANA EXTENDS INTO THE WESTERN GULF AND PROVIDES NORTHERLY- NORTHWESTERLY WIND FLOW OF 5-10 KT W OF 90W AND OF 15-20 KT ELSEWHERE. SURFACE RIDGING WILL CONTINUE TO BUILD IN THE WAKE OF THE FRONT THROUGH SAT. A NEW COLD FRONT WILL MOVE INTO THE W GULF SUN MORNING. CARIBBEAN SEA... A MIDDLE LEVEL TROUGH WITH A BASE OVER THE NW CARIBBEAN SUPPORTS A COLD FRONT THAT ENTERS THE BASIN BY WESTERN CUBA NEAR 22N83W AND THEN EXTENDS ALONG 18N86W TO NW HONDURAS NEAR 15N87W. UPPER LEVEL DIFFLUENCE SUPPORTS SHOWERS WITHIN 90 NM EITHER SIDE OF THE COLD FRONT BOUNDARY S OF 21N. A BROAD UPPER RIDGE OVER THE WESTERN ATLC EXTENDS INTO THE CARIBBEAN WITH WATER VAPOR IMAGERY INDICATING DRY STABLE AIR ACROSS THE CENTRAL AND EASTERN BASIN. HOWEVER...SSMI TPW IMAGERY SHOW PATCHES OF LOW LEVEL MOISTURE ACROSS THE WINDWARD PASSAGE AND EASTERN CUBA AS WELL AS ENTERING THE EASTERN BASIN WHICH MAY ENHANCE PASSING SHOWERS IN THESE REGIONS EARLY THIS MORNING. OTHERWISE...TRADES OF 15-20 KT ARE ACROSS THE BASIN E OF 77W WHILE LIGHTER SOUTHEASTERLY WIND FLOW DOMINATE THE NW CARIBBEAN. THE COLD FRONT WILL CONTINUE TO MOVE SE OVER CUBA AND THE NW BASIN AND WILL BEGIN TO DISSIPATE EARLY SAT. HISPANIOLA... DRY AIR SUBSIDENCE FROM ALOFT CONTINUES TO HINDER DEEP CONVECTIVE ACTIVITY OVER THE ISLAND. HOWEVER...A PATCH OF LOW LEVEL MOISTURE EXTENDING FROM EASTERN CUBA INTO THE ISLAND MAY GENERATE ISOLATED SHOWERS OVER HAITI...WINDWARD PASSAGE AND ADJACENT WATERS. LOOKING AHEAD...THE PROXIMITY OF A COLD FRONT IN THE WINDWARD PASSAGE MAY INCREASE SHOWER ACTIVITY IN THE AREA ON SAT. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS OVER THE EASTERN CONUS CONTINUES TO SUPPORT A FRONTAL SYSTEM OVER THE SW N ATLC ASSOCIATED WITH A 1004 MB LOW NEAR 32N76W. A COLD FRONT EXTENDS FROM THIS LOW ALONG 30N78W TO 27N80W...ACROSS CENTRAL-SOUTHERN FLORIDA AND THEN INTO THE NW CARIBBEAN. ISOLATED SHOWERS AND TSTMS ASSOCIATED WITH THIS SYSTEM ARE NOTED N OF 26N W OF 73W. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A 1023 MB HIGH NEAR THE AZORES AND A 1023 MB HIGH NEAR 26N43W. GALE FORCE WINDS ARE EXPECTED TO DEVELOP TONIGHT ON THE SW N ATLC ASSOCIATED WITH THE COLD FRONT. SEE SPECIAL FEATURES. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR