000 AGXX40 KNHC 080730 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 AM EDT WED JUN 08 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. AFTERNOON UPDATE... THERE IS ONLY ONE SIGNIFICANT CHANGE TO THE EARLIER THINKING...AND THAT IS WITH THE BROAD AREA OF LOW PRES IN THE NW CARIBBEAN. THIS SYSTEM IS BECOMING LESS ORGANIZED UNDER WESTERLY SHEAR. OBSERVATIONS NEAR THE LOW DO NOT SUGGEST AS EXTENSIVE AN AREA OF 20 KT WINDS AS SEEN LAST NIGHT...SO THE AREA WAS SHRUNK TO WITHIN 180 NM OF THE LOW IN THE SHORT RANGE. THE LOW WILL BE SLOW TO MOVE AWAY FROM ITS CURRENT POSITION NEAR 18N82W...BUT SHOULD FINALLY LIFT N THU AS UPPER TROUGHING OVER THE GULF OF MEXICO AMPLIFIES AND PICKS THE SYSTEM UP INTO ITS EASTERN EDGE. THE NHC-HPC MEDR CONFERENCE CALL AGREED ON A SOLUTION THAT CARRIES THE LOW INTO THE STRAITS OF FL FRI AND WEAKENS THE SYSTEM OVER THE SOUTHERN FL PENINSULA SAT. CONFIDENCE IS STILL LOW IN THE MODELS...ESPECIALLY AS THE 12Z GFS WAS DEEMED A WESTERN OUTLIER WITH THE TRACK ON THE CONFERENCE CALL. ------------------------------------------------------------- PREV DISCUSSION... GULF OF MEXICO... A WEAK 1015 MB HIGH CENTER IS ANALYZED NEAR 27N88W AT 0600 UTC. LATEST OBSERVATIONAL REPORTS FROM BUOYS THROUGHOUT INDICATE LIGHT WINDS AND LOW SEAS THROUGHOUT. THE EXCEPTION IS IN THE FAR SOUTHERN PORTIONS OF THE MIDDLE AND EASTERN ZONES WHERE A SLIGHTLY TIGHTER PRES GRADIENT THERE DUE TO THE COMBINATION OF BROAD LOW PRES IN THE WESTERN CARIBBEAN AND THE HIGH IS RESULTING IN NE-E 15 TO 20 KT WINDS. 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 MAXING UP TO 6 FT. WAVEWATCH GUIDANCE LOOKS REASONABLE FOR THE GULF...AND WILL LEAN TOWARDS THE GUIDANCE FOR THIS FORECAST PERIOD. MODELS DEPICT THE HIGH TO LIFT NW THROUGH THE NEXT 24 HOURS AS THE BROAD LOW PRES AREA IN THE CARIBBEAN SLOWLY MOVES IN A NLY DIRECTION OVER THE NEXT COUPLE OF DAYS. UNCERTAINTY STILLS REMAINS HIGH AS TO FUTURE IMPLICATIONS OF THIS LOW PRES AREA ON THE THE AREA/S WINDS AND SEAS AS FORECAST TRACK REMAINS QUITE OPEN AS TO WHERE EXACTLY THE LOW PRES WILL TRACK ONCE IT APPROACHES CUBA OR THE YUCATAN PENINSULA IN ABOUT 48 HOURS. EARLIER IT WAS THOUGHT THAT THE 15-20 KT WINDS AS STATED ABOVE WOULD DECREASE TODAY...BUT WITH THE SYNOPTIC SETUP OF LOW PRES TO THE S AND HIGH PRES ACROSS THE GULF REMAINING THROUGH THE NEXT FEW DAYS WILL CONTINUE TO MENTION 15-20 KT WINDS THROUGH FRI IN FAR SOUTHERN EASTERN GULF...AND THROUGH SAT IN THE FAR SOUTHERN MIDDLE GULF. THERE IS A VERY GOOD POSSIBILITY THAT THESE WINDS MAY HAVE TO BE ADJUSTED BASED ON TIMING AND EVOLUTION...IF ANY...OF THE LOW PRES IN THE CARIBBEAN AS IT APPROACHES THE GENERAL VICINITY OF WESTERN CUBA AND GULF AS GLOBAL MODELS SUGGEST THROUGH THE END OF WEEK. 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 INTIATED BY AN UPPER LEVEL CYCLONIC CIRCULATIION OVER THE N CENTRAL GULF OF MEXICO AND ITS ASSOCIATED BROAD CYCONIC FLOW. S 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 FORECATS TO BE NEAR WESTERN CUBA AND FAR SE GULF OF MEXICO... BUT REMAINS UNCERATIN 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 UPDWARD ALLOWING FOR THE CURRENT LIGHT E-SE WINDS OF 10-15 KT TO INCREASE TO 20 KT THU THROUGH SAT. BEGIND THE WAVE...E WINDS HAVE INCREASED TO 15-20 KT IN THE TROPICAL N ATLC ZONE. A WEAKER PRES GRADIENT ELSEWHERE 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 GRADUENT 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. ANOTHER SCENARIO DEPICTED BY THE GLOBAL MODELS AND THE REGIONAL NAM IS FOR THE CARIBBEAN LOW TO ACTUALLY TRACK MORE TO THE NE CROSSING CUBA AND MOVING TO ALONG THE FLORIDA FRI AND SAT. THE GFS IS THE EXCEPTION BY KEEPING IT FARTHER TO THE E. FOR NOW WILL DESCRIBE AND ANALYZE THIS FEATURE AS A TROUGH ON NEXT ISSUED FORECAST. THE MAIN EMPHASIS WILL BE THE INCREASING GRADIENT OVER THE SOUTHERN WATERS AS THE WEAK LOW FORMS THERE THROUGH THE NEXT 24 TO 36 HOURS WITH S-SW WINDS TO THE SE OF THE LOW INCREASING TO 20 KT OR MAYBE TO 25 KT. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE