000 AGXX40 KNHC 130756 RRA MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 355 AM EDT FRI JUL 13 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE WEAK SURFACE RIDGE HAS SHIFTED N TO OVER THE SE U.S. AS A RATHER PERTURBED UPPER ATMOSPHERIC ENVIRONMENT REMAINS ACROSS THE AREA. AN UPPER LEVEL LOW N OF THE YUCATAN PENINSULA AT 24N88W IS SLOWLY MOVING W WHILE A NARROW UPPER TROUGH EXTENDS FROM ANOTHER UPPER LEVEL LOW OVER WRN GEORGIA S TO WRN CUBA. A LARGER UPPER TROUGH IS MOVING ESE ACROSS ERN TEXAS AND THE FAR WRN GULF. A SURFACE TROUGH ASSOCIATED WITH THE LOW AT 24N88W IS ANALYZED FROM 26N86W TO INLAND THE NW YUCATAN PENINSULA AT 20N89W. SCATTERED SHOWERS AND TSTMS ARE ALONG AND NEAR THE TROUGH MOVING W. OTHER SCATTERED SHOWERS AND TSTMS ARE OVER THE FAR ERN WATERS E OF 84W ARE PRIMARILY ASSOCIATED WITH A WEAK LOW THAT EARLIER LAST NIGHT MOVED W ACROSS TAMPA BAY. LATEST BUOY OBSERVATIONS AND OIL RIG PLATFORMS SHOW SE WINDS OF 10-15 KT W OF 88W...AND NE-E WINDS OF 5-10 KT E OF 88W N OF 27N AND E-SE WINDS OF 5-10 KT S OF 27N E OF 88W. THE AFOREMENTIONED FEATURES WILL BE THE ONES TO PERSIST ACROSS THE AREA THROUGH THE UPCOMING WEEKEND AS THE WRN EXTENSION OF THE ATLC RIDGE REMAINS PRETTY MUCH CONFINED TO THE SE U.S. BEFORE SHIFTING SOME TO THE S OVER THE FLORIDA PENINSULA EARLY NEXT WEEK PER MODEL CONSENSUS. BOTH GFS AND NOGAPS PICK UP ON THE LOW PRES FEATURE THAT MOVED OFFSHORE TAMPA BAY LAST NIGHT AND TAKE IT IN A NW MOTION TOWARDS SE LOUISIANA WITH THE GFS BEING THE FASTER IN TAKING IT INLAND THAT COAST SAT NIGHT SAT NIGHT...AND THE NOGAPS TAKING INLAND THE SE LOUISIANA BY 12 UTC SUN MORNING. THE OTHER MODELS GENERALLY KEEP IT AS A TROUGH THAT PASSES TO THE S OF LOUISIANA GRADUALLY WASHING IT OUT BY SUN EVENING. MODELS DO AGREE THAT THIS FEATURE WILL REMAIN WEAK WITH WINDS OF 10-15 KT AS IT PROGRESSES ACROSS THE N CENTRAL GULF THROUGH THE WEEKEND...AND DO NOT SEE ANY NEED TO DEVIATE FROM PREVIOUS FORECAST WITH WINDS AND SEAS WITH RESPECT TO FEATURE AS IT TRAVERSES THE REMAINDER OF THE ERN TODAY AND TONIGHT...AND THEN THE CENTRAL PORTION OF THE GULF SAT THROUGH MUCH OF SUN. THE MULTIGRID WAVEWATCH GUIDANCE APPEARS FAVORABLE FOR THIS FORECAST PACKAGE. SW N ATLC S OF 31N W OF 65W... THE PRELIMINARY 06 UTC ANALYSIS HAS THE RIDGE THAT WAS RECENTLY ACROSS THE FAR NRN BOUNDARY NOW TO THE N OF THE REGION NEAR 33N. SATELLITE WATER VAPOR IMAGERY SHOWS A LARGE UPPER LEVEL LOW AT 25N65W MOVING W WITH ITS CIRCULATION EXTENDING FROM 18N TO 31N AND TO THE E OF THE BAHAMAS. THE ASSOCIATED SURFACE INVERTED- TROUGH EXTENDS FROM NEAR 30N65W TO 23N68W. SCATTERED SHOWERS AND TSTMS ARE SEEN FROM 23N TO 29N E OF 70W. A PARTIAL ASCAT PASS FROM 0050 UTC LAST NIGHT INDICATED A NE TO SE WIND SHIFT ACROSS THE TROUGH WITH WINDS IN THE RANGE OF 15-20 KT. THE TROUGH WILL CONTINUE WESTWARD IN PHASE WITH THE UPPER LOW ...EXPECTED TO REACH TO ALONG 30N68W TO 23N69W TONIGHT...FROM 30N70W TO 23N71W SAT MORNING...FROM 30N71W TO SE BAHAMAS BY EARLY SAT EVENING...AND FROM NEAR 30N71W TO NEAR THE CENTRAL BAHAMAS SUN EVENING AND TO THE NW PORTION LATE SUN NIGHT INTO MON AS IT BECOMES DIFFUSE. THE GFS/ECMWF AND NOGAPS MODEL GUIDANCE SUGGEST THAT A WEAK COLD FRONT WILL PASS JUST TO THE NE OF THE FORECAST WATERS TO THE SW OF BERMUDA SAT NIGHT AND BECOME STATIONARY. HIGH PRES OF 1022 MB THE BECOMES ESTABLISHED NEAR 28N64W BY SUN NIGHT WITH A RIDGE NW TO THE SE U.S. TO THE S OF THE RIDGE...E-SE WINDS OF 10-15 KT E OF THE BAHAMAS WILL INCREASE TO 15-20 KT TONIGHT AND THROUGH MON AS A TROPICAL WAVE...CURRENTLY IN THE TROPICAL N ATLC E OF THE FORECAST WATERS...PASSES TO THE S OF THE AREA FURTHER SUSTAINING THE GRADIENT TO MAINTAIN THE E 15-20 KT WINDS INTO EARLY NEXT WEEK. GIVEN THAT THE LATEST GFS MODEL LOOKS REASONABLE...PLAN TO COMBINE IT INTO THE PREVIOUS PUBLISHED GRID SET. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE TROPICAL WAVE THAT AT 00 UTC WAS ANALYZED EXTENDING FROM NW CUBA NWD INTO THE ERN GULF OF MEXICO IS NOT IDENTIFIABLE ANY LONGER AT THE SURFACE. THE ELY TRADES HAVE DIMINISHED TO 20 KT IN THE S CENTRAL PORTION OF THE SEA NEAR COAST OF COLOMBIA...WITH TRADES ELSEWHERE AT LIGHTER SPEEDS OF 10-15 KT. SEAS ARE IN THE RANGE OF 3-5 FT...WITH HIGHER SEAS OF 6-8 FT IN THE SW PART OF THE CARIBBEAN. THE NEXT SURGE OF NE WINDS AT 20 KT WILL REACH ALONG 55W LATE THIS AFTERNOON AND INTO THIS EVENING...AND SPREAD RAPIDLY W ACROSS THE E AND CENTRAL CARIBBEAN THROUGH SAT NIGHT...AND INTO THE GULF OF HONDURAS SUN NIGHT INTO MON. THE NEXT TROPICAL WAVE IS APPROACHING 50W AS IT QUICKLY MOVES W. THIS WAVE IS EXPECTED TO REACH 55W TONIGHT...AND MOVE INTO THE ERN CARIBBEAN SAT NIGHT...REACH NEAR 66W SUN NIGHT...AND ROUGHLY NEAR 72W MON NIGHT. THE PRES GRADIENT WILL STRENGTHEN IN THE WAKE OF WAVE ALLOWING FOR NE WINDS TO INCREASE TO MOSTLY 25 KT IN THE S CENTRAL PORTION OF THE SEAS WITH WINDS TO 30 KT VERY POSSIBLE ALONG THE COAST OF COLOMBIA. MOST OF THE WAVEWATCH GUIDANCES BUILD SEAS HIGH IN THAT PART OF THE SEAS SUN AND MON WITH VALUES IN THE RANGE OF 10-12 FT. THE ECMWF WAVE GUIDANCE IS A LOT LOWER THAN THE REST OF THE GUIDANCE INDICATING SEAS OF ONLY 8 FT SUN AND MON. FOR THIS FORECAST WILL LEAN TOWARDS THE HIGHER VALUES FOR SEAS AS SUGGESTED BY THE MAJORITY OF THE MODELS DUE TO LONG FETCH OF THE FORECAST INCREASING TRADES OVER MUCH OF THE CENTRAL AND ERN PORTIONS OF THE SEA. TRADES INCREASE TO 20 KT OVER THE NRN AND CENTRAL SECTIONS OF THE TROPICAL N ATLC TONIGHT THROUGH MON WITH SEAS BUILDING TO 9 FT. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE