000 AGXX40 KNHC 150619 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 219 AM EDT FRI AUG 15 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... TODAY THROUGH SAT NIGHT...SFC RIDGE HAS BEEN SLOWER THAN INITIALLY EXPECTED TO BEGIN ITS NWD DRIFT AND IS STILL SITUATED FROM THE FLORIDA KEYS TO THE NW GULF. SW/W WINDS OVER THE NE GULF ARE NOW DIMINISHING AS LOW PRES MOVES AWAY FROM THE AREA AND WILL BE 10 KT OR LESS BY LATER THIS AFTERNOON. C-MAN OBS OVER THE FL KEYS INDICATE THAT AN AREA OF HIGH PRES HAS FORMED ALONG THE RIDGE AXIS TO THEIR W...AND THIS FEATURE IS EXPECTED MOVE NW INTO THE MIDDLE GULF THROUGH SAT WITH THE RIDGE AXIS LIFTING N TO S/CNTRL FLORIDA ON SAT THEN ENTIRELY DISSIPATING SAT NIGHT. THIS WILL TEND TO KEEP WINDS LIGHT OVER THE ERN PART OF THE GULF...BUT WITH A STRONGER NLY COMPONENT AS THE AREA LIES E OF THE HIGH. ELSEWHERE...ELY WINDS OVER THE SW GULF WILL INCREASE TO 20 KT EACH NIGHT NEAR THE YUCATAN COAST. SUN THROUGH TUE...HIGH PRES REMAINS OVER THE NRN MIDDLE GULF ON SUN AS AN AREA OF LOW PRES MOVES NW ACROSS THE WATERS W OF THE BAHAMAS. THIS WILL CONTINUE A N/NE WIND FIELD OVER THE ERN GULF ON SUN. THE HIGH MELDS WITH A BUILDING RIDGE AXIS N OF THE AREA AND WILL BEGIN TO TURN WINDS OUT OF THE NE/E MON AND TUE. AT THIS POINT MODEL GUIDANCE SUGGESTS THAT THE SW ATLC LOW WILL MAKE A NWD TURN...WHICH SHOULD KEEP WINDS LIGHT OVER THE GULF THROUGH THE FCST PERIOD. CARIBBEAN AND TROPICAL N ATLC... TODAY THROUGH SAT NIGHT...A TRPCL WAVE IS LOCATED ALONG 66W WITH AN ASSOCIATED AREA OF LOW PRES LOCATED OFF THE N COAST OF PUERTO RICO. QSCAT DATA SHOW THAT WINDS HAVE GENERALLY DIMINISHED LESS THAN 20 KT OVER THE E/CNTRL CARIBBEAN WITH ALL THE STRONGEST WINDS OCCURRING N OF THE GREATER ANTILLES...EXCEPT FOR A N/NE SWATH OF 15-20 KT THROUGH THE MONA PASSAGE. THE WAVE IS EXPECTED TO MOVE W NEAR 15 KT AND REACH NEAR JAMAICA BY SAT NIGHT...BUT STILL THE TRADES ACROSS THE CARIBBEAN WATERS ARE EXPECTED TO REMAIN RELATIVELY LIGHT. FARTHER E...ANOTHER TRPCL WAVE IS ALONG 47W WITH A LOW NEAR 13N47W AND IS EXPECTED TO EVENTUALLY CROSS 55W BY SAT NIGHT. WINDS PRECEDING THE LOW ARE ACTUALLY EXPECTED TO DIMINISH AS THE WAVE APPROACHES THE TRPCL N ATLC ZONE AND WOULD LIKELY NOT INCREASE UNTIL THE WAVE AXIS PASSES LATE SAT NIGHT INTO SUN. SUN THROUGH TUE...THE WESTERN TRPCL WAVE WILL REACH BETWEEN JAMAICA AND THE CAYMAN ISLANDS BY SUN...NEAR 84W MON...THEN CROSS INTO THE YUCATAN ON TUE. WINDS OVER THE S/CNTRL CARIBBEAN MAY INCREASE BACK TO 20 KT BY LATE SUN AFTER THE WAVE PASSAGE AND WILL LIKELY CONTINUE THROUGH TUE. THE EASTERN WAVE WILL BE MOVING ACROSS THE TRPCL N ATLC ZONE ON SUN WITH THE GFS-UKMET-NOGAPS ENSEMBLE MEAN SHOWING THE ASSOCIATED LOW MOVING NW OVER THE FAR NRN WATERS. THE WAVE WILL CONTINUE WWD INTO THE E CARIBBEAN MON AND TUE BUT WILL REALLY FIZZLE OUT AS THE LOW MOVES NW AND WEAKENS. WINDS MAY STRENGTHEN TO 20 KT OVER PARTS OF THE TRPCL N ATLC ZONE LATE TUE AS ANOTHER TRPCL WAVE APPROACHES THE AREA. SW N ATLC... TODAY THROUGH SAT NIGHT...SFC OBSERVATIONS AND RADAR IMAGERY INDICATE THAT THE AREA OF LOW PRES NEAR THE ANTILLES IS NOW NEAR THE N COAST OF PUERTO RICO. THE EVENING QSCAT PASS SHOWED THAT ALL THE STRONG WINDS ASSOCIATED WITH THE SYSTEM ARE LOCATED N OF THE CENTER WITH A SWATH OF 20-30 KT WINDS FROM 18N-22N BETWEEN 62W-67W SPREADING W. THE SYSTEM REMAINS DISORGANIZED WITH NO WELL-DEFINED CENTER...BUT THE SYSTEM HAS A GOOD CHANCE TO DEVELOP INTO A TRPCL CYCLONE AS IT MOVES INTO A MORE FAVORABLE ENVIRONMENT. LATEST MODEL GUIDANCE SKIRTS THE CENTER NEAR THE N COASTS OF PUERTO RICO AND HISPANIOLA IN THE SHORT-TERM...ENDING UP N OF THE WINDWARD PASSAGE SAT NIGHT. MOST OF THE INTENSITY GUIDANCE ALSO GRADUALLY STRENGTHENS THE SYSTEM...BUT THIS CANNOT HAPPEN UNTIL IT FORMS A WELL-DEFINED CIRCULATION. ELSEWHERE... THE SFC RIDGE WILL EXTEND FROM 30N65W TO S FLORIDA TODAY AND LIFT N TO 30N THROUGH SAT NIGHT AS THE AREA OF LOW PRES MOVES W. SUN THROUGH TUE...CONFIDENCE IN THE FCST POSITION OF THE LOW DECREASES FROM SUN BEYOND...BUT 18Z MODEL GUIDANCE WAS SUGGESTING A NWD TURN TO OCCUR ONCE THE LOW MOVED W OF THE BAHAMAS. TIMING IN THESE SCENARIOS IS ALWAYS TRICKY AND IN FACT SOME OF THE 00Z GUIDANCE IS NOW SHOWING A MORE WWD SHIFT. THESE TRENDS WILL LIKELY CONTINUE BUT FOR NOW THE ENVELOPE OF MODELS PLACES THE LOW OVER THE ATLC ANYWHERE BETWEEN 74W AND FLORIDA BY TUE. FCST WILL MENTION A WINDS TO 30 KT WITH A PSBL TRPCL CYCLONE...WITH UNDERSTANDING THAT THIS COVERS THE POSSIBILITY OF MUCH STRONGER WINDS. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. .FORECASTER BERG. TROPICAL PREDICTION CENTER.