000 AXNT20 KNHC 211130 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI MAR 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 1130 UTC. ...SPECIAL FEATURE... A GALE WARNING IS IN EFFECT FOR A PORTION OF THE SOUTHERN CARIBBEAN SEA FROM 11N TO 13N BETWEEN 73W AND 77W AS HIGH PRES N OF THE AREA INTERACTS WITH LOW PRES OVER NORTHERN COLOMBIA. SEAS WITHIN THE WARNING AREA ARE FORECAST TO BE IN THE RANGE OF 9-13 ...DIMINISHING TO 8 TO 11 FT LATER THIS MORNING AND CONTINUING THROUGH SUN. THE GALE WINDS ARE FORECAST TO DIMINISH TO JUST BELOW GALE FORCE LATER THIS MORNING AS THE HIGH PRES N OF THE AREA SHIFTS EASTWARD. PLEASE SEE THE HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC AT THE COAST OF GUINEA-BISSAU...AND CONTINUES S TO 5N16W WHERE LOW LEVEL WINDS SUGGEST THE ITCZ BEGINS AND CONTINUES TO SW TO 1N25W TO S OF THE EQUATOR NEAR 35W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE MONSOON TROUGH. ...DISCUSSION... GULF OF MEXICO... THE UPPER LONGWAVE TROUGH HAS SHIFTED TO E OF FLORIDA. IN IT WAKE...BROAD UPPER HIGH PRES HAS BECOME THE DOMINANT FEATURE COVERING THE ENTIRE GULF WITH THE ASSOCIATED ANTICYCLONE CENTERED OVER SOUTHERN GUATEMALA. MODERATE SUBSIDENCE ALOFT HAS USHERED IN DRY AND STABLE AIR THROUGHOUT...EXCEPT N OF 27N WHERE SCATTERED TO BROKEN CIRRUS CLOUDS STREAMING EASTWARD ARE DUE TO A JET STREAM BRANCH THAT STRETCHES FROM THE EASTERN PACIFIC ENE ACROSS NORTHERN MEXICO...AND TO ACROSS THE FAR NE GULF WHERE MAXIMUM JET CORE WINDS ARE IN THE 90-140 KT RANGE. THE PRESENT DRY AND STABLE CONDITIONS ALOFT ARE KEEPING THE MOISTURE CONTENT THROUGHOUT ALL ATMOSPHERIC LEVELS TO A MINIMUM. ONLY ISOLATED SHOWERS ARE POSSIBLE OVER THE SOUTHERN PORTION OF THE GULF S OF 24N BETWEEN 87W-94W. REMNANT LOW-LEVEL MOISTURE FROM A PREVIOUS FRONTAL BOUNDARY IS SEEN AS SCATTERED LOW CLOUDS WITH POSSIBLE ISOLATED SHOWERS OVER AND NEAR THE YUCATAN CHANNEL...AND N TO NEAR 24N. IR NIGHT CHANNEL SATELLITE IMAGERY SHOWS LOW CLOUDINESS BANKED ALONG THE SIERRA MADRE MOUNTAINS OF MEXICO. SURFACE RIDGING IS PRESENT ELSEWHERE OVER THE GULF. THE RIDGE IS FORECAST TO WEAKEN ON SAT IN RESPONSE TO A COLD FRONT FORECAST TO MOVE INTO THE NW GULF WATERS LATE ON SUN. CARIBBEAN... A BROAD UPPER RIDGE COVERS THE CARIBBEAN AND EXTENDS N OVER THE GULF OF MEXICO AND WESTERN ATLC ANCHORED BY AN ANTICYCLONE OVER SOUTHERN GUATEMALA. SATELLITE WATER VAPOR IMAGERY SHOWS DRY STABLE AIR AT THE MID AND UPPER LEVELS ACROSS THE ENTIRE BASIN. A DISSIPATING STATIONARY FRONT EXTENDING FROM THE WESTERN ATLC SW TO CENTRAL AND WESTERN CUBA. PATCHES OF RESIDUAL SURFACE TO LOW-LEVEL MOISTURE FROM THIS FRONT IS ONLY GENERATING ISOLATED SHOWERS TO THE LEE OF CUBA BETWEEN 77W-81W. SIMILAR MOISTURE PATCHES WITH POSSIBLE ISOLATED SHOWERS ARE MOVING WSW IN THE TRADE WIND FLOW BETWEEN HAITI AND THE NE COAST OF HONDURAS. THE REMAINDER OF THE CARIBBEAN IS UNDER THE INFLUENCE OF THE UPPER RIDGE WITH RATHER DRY AND STABLE CONDITIONS NOTED. A MID/UPPER LEVEL TROUGH...THE TAIL END OF THE ATLC TROUGH DESCRIBED BELOW...IS OVER THE FAR EASTERN CARIBBEAN IN THE VICINITY OF THE LESSER ANTILLES IS ABOUT STATIONARY FOR THE TIME BEING. THE PRESENCE OF DRY AND STABLE AIR THROUGHOUT IS ONLY ALLOWING FOR ISOLATED SHOWERS MOVING NW TO EXIST OVER THE FAR NE CARIBBEAN. THIS TROUGH IS FORECAST TO MOVE SLOWLY EASTWARD ON SAT WHILE DAMPENING OUT. FRESH TO LOCALLY STRONG TRADE WINDS WILL PERSIST ACROSS THE S/CENTRAL CARIBBEAN THROUGH THE WEEKEND WITH HIGHEST WINDS OCCURRING NEAR THE COAST OF COLOMBIA DURING LATE NIGHT AND EARLY MORNING HOURS. MODERATE TO LOCALLY FRESH TRADE WINDS WILL PREVAIL ELSEWHERE...EXCEPT FOR A GENTLE TO MODERATE BREEZE IN THE NW CARIBBEAN. HISPANIOLA... LATEST SATELLITE IMAGERY SHOWS MAINLY SCATTERED LOW CLOUDS OVER THE MUCH OF THE CENTRAL AND WESTERN PORTIONS OF THE ISLAND. ISOLATED SHOWERS ARE POSSIBLE IN SOME LOCATIONS. WITH AMPLE DRY AIR ALOFT AS SEEN IN THE VAPOR IMAGERY...LOW-LEVEL MOISTURE IS FORECAST TO REMAIN AT A MINIMUM THROUGH THE NEXT 24-48 HRS WITH THE EXCEPTION OF SHOWER ACTIVITY THAT FORMS WITH AFTERNOON HEATING. ATLANTIC... THE BROAD UPPER RIDGE OBSERVED OVER THE CARIBBEAN EXTENDS NEWD OVER TO ACROSS THE WESTERN ATLC. A LONGWAVE TROUGH TYPE FEATURE ENTERS THE AREA THROUGH 32N77W...AND EXTENDS TO NEAR THE NORTHERN BAHAMAS. THE SURFACE COLD FRONT IS N OF THE AREA...EXTENDING SW TO NEAR 31N70W. MOSTLY BROKEN TO OVERCAST MID/UPPER CLOUDS WITH BROKEN LOW AND MID-LEVEL UNDERNEATH WITH SCATTERED SHOWERS AND ISOLATED TSTMS ARE NOTED WITHIN 180 NM E OF THE FRONT. A WEAK MID/UPPER TROUGH IS SEEN EXTENDING FROM A WEAK UPPER LOW NEAR 30N26W SW TO 24N40W TO 23N50W TO 16N60W AND SW TO NE VENEZUELA. A WEAK COLD FRONT IS ANALYZED TO THE W OF THIS TROUGH FROM NEAR 32N51W SW TO 28N56W...WHERE IT BECOMES STATIONARY NW TO 29N35W...THEN SW TO 28N67W WHERE IT BEGINS TO DISSIPATE TO THE CENTRAL BAHAMAS AND TO CENTRAL CUBA NEAR 22N78W. ISOLATED SHOWERS ARE WITHIN 60 NM OF THE FRONT E OF THE BAHAMAS. THE REMAINDER OF THE ATLC E OF 68W IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1028 MB HIGH JUST N OF THE AREA AT 33N29W. WEAKER HIGH PRES IS PRESENT W OF 68W WITH A 1017 MB HIGH AT 29N73W. ISOLATED SHOWERS ARE NOTED ON NWS RADAR TO BE OVER THE WATERS BETWEEN THE BAHAMAS AND 80W. A WEAKER COLD FRONT IS FORECAST TO SWEEP ACROSS THE NORTHERN PORTION OF THE WESTERN ATLC FRI MERGING WITH THE SECOND FRONT DESCRIBED ABOVE WITH THE MERGED FRONT DISSIPATING FROM NEAR 32N62W TO THE SOUTHERN BAHAMAS BY SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE