000 AGXX40 KNHC 080752 CCA MIMATS MARINE WEATHER DISCUSSION...CORRECTED NWS NATIONAL HURRICANE CENTER MIAMI FL 230 AM EDT WED JUN 08 2011 CORRECTED TO INCLUDE MENTION OF ASCAT PASS UNDER GULF OF MEXICO MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO...CORRECTED WEAK RIDGE IS ALONG 29N...AND A WEAK SURFACE TROUGH IS ALONG 90W S OF 25N MOVING W ABOUT 13 KT. LATEST BUOY REPORTS THROUGHOUT INDICATE LIGHT WINDS AND LOW SEAS THROUGHOUT. AGAIN THE EXCEPTION IS IN THE FAR SOUTHERN PORTIONS OF THE MIDDLE AND EASTERN ZONES WHERE A SLIGHTLY TIGHTER PRES GRADIENT THERE DUE TO THE RIDGE TO THE N AND AND WEAK LOW PRES IN THE WESTERN CARIBBEAN IS RESULTING IN NE-E 15 TO 20 KT WINDS. THESE WINDS WERE CONFIRMED BY AN ASCAT PASS FROM 0226 UTC AND SHIP "A8MI2" IN THE LOWER STRAITS OF FLORIDA. BUOY REPORTS SHOW SEA HEIGHTS IN THE RANGES OF 1-3 FT...EXCEPT IN THE FAR SOUTHERN PORTIONS OF THE MIDDLE AND EASTERN ZONES WHERE SEAS ARE IN THE RANGE OF 4-7 FT. THE HIGHEST VALUES NEAR WESTERN CUBA AND THE YUCATAN CHANNEL. WAVEWATCH GUIDANCE LOOKS REASONABLE FOR THE GULF...AND WILL USE THE GUIDANCE THROUGHOUT THIS FORECAST CYCLE. MODELS SUGGEST THAT THE RIDGE WILL CHANGE LITTLE THROUGH SAT AS THE CARIBBEAN LOW PRES AREA MOVES GENERALLY NW AND N AFTER THIS MORNING. WITH THIS LOW NOW HAVING WEAKEN SINCE YESTERDAY...ITS IMPLICATIONS ON THE THE AREAS WINDS AND SEAS SHOULD BE MINIMAL WITH WINDS CONTINUING AT 15-20 KT IN THE SE GULF THROUGH FRI BUT SHIFTING TO E-SE AS THE LOW MOVES TO THE NW AND N. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE BROAD AREA OF LOW PRES THAT OVER THE NORTHWESTERN CARIBBEAN SEA DURING THE PAST SEVERAL DAYS HAS BECOME LESS DEFINED AND MORE ELONGATED SINCE 24 HOURS AGO UNDER SW UPPER LEVEL SHEAR INITIATED BY AN UPPER LEVEL CYCLONIC CIRCULATION OVER THE N CENTRAL GULF OF MEXICO AND ITS ASSOCIATED BROAD CYCLONIC FLOW. AS OF 0600 UTC THIS MORNING ITS CENTER WAS NEAR 18N81W...OR ABOUT 70 NM SSW OF GRAND CAYMAN ISLAND AS 1008 MB. A TROUGH EXTENDS FROM THE LOW SW TO INLAND NORTHEASTERN HONDURAS...WHILE ANOTHER TROUGH EXTENDS NORTHEASTWARD TO HISPANIOLA. SATELLITE IMAGERY SHOWS THAT AXIS OF AMPLE DEEP MOISTURE E OF THE LOW HAS SHIFTED NORTHWARD TO N OF 16N. CLUSTERS OF TSTMS ARE OCCURRING ALONG THE TROUGH AXIS. GUSTY WINDS CAN BE EXPECTED WITH THIS ACTIVITY THROUGH THE NEXT 36-48 HOURS. AN ASCAT PASS FROM LATE LAST NIGHT SHOWED NE-E 15 KT WINDS TO THE N OF THE LOW...WHICH IS LIGHTER THAN WHAT WAS OCCURRING THE PAST FEW DAYS. SEAS N OF THE LOW TO 21N ARE MAXING OUT TO 7 FT. THE LOW WILL REMAIN NEARLY STATIONARY TROUGH THIS MORNING...THEN SLOWLY MOVE NW AND N IN RESPONSE TO THE UPPER LEVEL SYSTEM IN THE GULF. ITS FORECAST POSITION PAST THE NEXT 24-36 HOURS IS FORECAST TO BE NEAR WESTERN CUBA AND FAR SE GULF OF MEXICO... BUT REMAINS UNCERTAIN AS TO EXACTLY WHERE AND WHETHER IT WILL REMAIN A LOW OR TROUGH WHEN IT REACHES THOSE AREAS. A TROPICAL WAVE APPROACHING THE SE CARIBBEAN EXTENDS 15N58W INTO NORTHERN GUYANA MOVING W 10-15 KT. THE WAVE WILL CONTINUE TO TRACK THROUGH THE FAR SOUTHERN PORTION OF THE EASTERN CARIBBEAN THROUGH FRI. THE PRES GRADIENT OVER THE SOUTHERN PORTIONS OF THE EASTERN AND CENTRAL CARIBBEAN SEA WILL PULSATED UPWARD ALLOWING FOR THE CURRENT LIGHT E-SE WINDS OF 10-15 KT TO INCREASE TO 20 KT THU THROUGH SAT. BEHIND THE WAVE...E WINDS HAVE INCREASED TO 15-20 KT IN THE TROPICAL N ATLC ZONE. A WEAKER PRES GRADIENT ELSEWHERE ACROSS THE CARIBBEAN AND TROPICAL N ATLC WILL MAINTAIN LIGHT WIND CONDITIONS THROUGHOUT. SW N ATLC... NE TO E WINDS OF 15-20 KT CONTINUE OVER THE FAR SW WATERS...AND FROM 22N- 25N E OF BAHAMAS DUE TO A TIGHT PRES GRADIENT BETWEEN HIGH PRES BUILDING SE ACROSS THE NW WATERS...AND THE LOW PRES AND TROUGH IN THE NORTHERN CARIBBEAN SEA. MAXIMUM SEAS OBSERVED ARE ABOUT 6 FT W OF THE BAHAMAS AND OVER THE STRAITS OF FLORIDA. GLOBAL MODELS FORECAST THE AREA OF HIGH PRES TO SLIDE SE THROUGH SAT AS IT WEAKENS. IN THE MEANTIME WEAK LOW PRES FORMS OVER THE SE WATERS NEAR 22N65W...AND MOVE TO E OF THE AREA AFTER 24 HOURS. UNCERTAINTY COMES TO PLAY INTO THE FORECAST BEGINNING IN ABOUT 48 HOURS AS GLOBAL MODELS AND THE REGIONAL NAM DEPICT THE SCENARIO OF THE CARIBBEAN LOW TO TRACK MORE TO THE NE CROSSING CUBA AND MOVING TO ALONG THE FLORIDA E COAST FRI AND SAT. THE GFS IS THE EXCEPTION BY TAKING IT NE ACROSS THE SE BAHAMAS...AND KEEPING IT TO THE E OF THE BAHAMAS FOR FRI AND SAT. FOR NOW WILL DESCRIBE AND ANALYZE THIS FEATURE AS A TROUGH ON NEXT ISSUED FORECAST AND GRAPHICAL CHARTS. ALL MODELS DO AGREE THAT THE MAIN EMPHASIS WITH THIS PROBABLE FEATURE WILL BE THE INCREASING GRADIENT OVER THE WESTERN ATLC WATERS AS THE LOW OR TROUGH TRACKS TO THE N FOR DAYS 4 AND 5. SO WILL HIGHLIGHT THIS FOR THIS FORECAST PACKAGE. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE