000 AGXX40 KNHC 190804 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 404 AM EDT THU AUG 19 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A WEAK RIDGE OF HIGH PRES EXTENDS FROM THE SW N ATLC W-SW ACROSS FLORIDA AND ACROSS THE GULF ALONG 25N. TO THE N...AND OLD FRONTAL TROUGH AND ELONGATED LOW PRES ARE DRAPED NE TO SW ACROSS THE GULF COAST STATES. TO THE S OF THE RIDGE...MODERATE ELY'S PREVAIL FROM THE STRAITS OF FLORIDA TO THE SW GULF. A LARGE AREA OF DEEP CNVTN HAS MOVED W OFF OF YUCATAN THIS EVENING AND WILL MOVE ACROSS THE BAY OF CAMPECHE AND INTO MEXICO BY MORNING...ACCOMPANIED BY STRONG GUSTY WINDS. THE N PORTIONS OF A TROPICAL WAVE WERE MOVING ACROSS THE NW CARIBBEAN AND CUBA AND SCRAPING THE ATLC WATERS SW OF THE BAHAMAS...AND THE STRAITS OF FLORIDA. A MID LEVEL WIND SURGE OF 30-35 KT THAT HAS MOVED ACROSS THE NRN CARIB AND ATLC ATLC THE PAST FEW DAYS...IGNITING STRONG CNVTN...WILL MOVE W BEHIND THE TROPICAL WAVE...AND ACROSS THE YUCATAN CHANNEL THROUGH EARLY AFTERNOON...AND ACROSS THE S CENTRAL GULF AND YUCATAN PENINSULA THIS EVENING AND TONIGHT. STRONG CNVTN WITH FREQUENT LIGHTNING AND GUSTY WINDS SHOULD BE EXPECTED BEHIND THIS WAVE AS THE ASSOCIATED WIND SURGE TRACKS ACROSS THE AREA. WINDS S OF 23N ARE LIKELY TO INCREASE TO 15-20 KT AT THE SURFACE WITH THIS WAVE THIS MORNING THROUGH FRI. AS THE WAVE MOVES MORE NWLY ACROSS THE SW AND W GULF FRI NIGHT...DIURNAL CNVTN TYPICAL ACROSS THE YUCATAN IS LIKELY TO BE SIGNIFICANTLY ENHANCED AND WILL MOVE MORE NW ACROSS THE SW GULF...AND TOWARD UPPER MEXICO AND FAR S TEXAS AS IT DIMINISHES OVERNIGHT. THE WIND SURGE WITH AND BEHIND THE WAVE AND EXITING THE YUCATAN DURING THE EVENING MAY INCREASE TO 20-25 KT YIELDING SEAS 6-7 FT. THE WAVE AND ASSOCIATED WEATHER WILL THEN MOVE INTO MEXICO SAT EVENING AND NIGHT WITH GRADUALLY IMPROVING WEATHER BEHIND IT ACROSS THE SW GULF. HOWEVER...WIND AND SEAS TRAILING THE WAVE INTO MEXICO ARE NOT LIKELY TO SUBSIDE CONSIDERABLY UNTIL SUNDAY MORNING. WEAK HIGH PRE RIDGE AND LIGHT TO MODERATE WINDS WILL THEN PREVAIL ACROSS THE BASIN THROUGH MON. SW N ATLC... AN OLD FRONTAL TROUGH CONTINUES TO MEANDER IN A SNAKE LIKE FASHION ACROSS N PORTIONS OF THE AREA...WITH SCATTERED SHOWERS AND ISOLATED TSTMS FIRING UP ALONG EITHER SIDE OF THE BOUNDARY. THIS FEATURE MAY LINGER IN THE NW PORTION THROUGH THE END OF THE WEEK WITH MAINLY LIGHT WINDS OCCURRING IN THE VICINITY OF THE FEATURE. THE NORTHERN PORTION OF THE TROPICAL WAVE ACROSS THE NW CARIB WAS ACROSS CUBA NEAR 81/82W AND ALSO IGNITING SCATTERED TSTMS OFF THE NW CUBAN COAST AND THROUGH THE STRAITS OF FLORIDA. E TO E-SE WINDS OF 15-20 KT WILL ACCOMPANY THIS WEATHER THROUGH THIS CORRIDOR OVERNIGHT AND THROUGH THE MORNING HOURS...MAINLY S OF 24N...AND LIKELY PUSH SOME SHOWER AND TSTM ACTIVITY ACROSS S FLORIDA. OTHERWISE A 1016 MB HIGH PRES WAS CENTERED OVER NE PORTIONS OF THE AREA NEAR 28N68W WITH WEAK RIDGING EXTENDING TO THE NW BAHAMAS. THE HIGH CENTER WILL MOVE TO JUST NE OF THE CENTRAL BAHAMAS EARLY FRI AS A LOW TO MID LEVEL TROUGH CURRENTLY E OF THE AREA ALONG 50W MOVES TO THE W BUT WILL DISSIPATE SAT BEFORE ENTERING THE AREA. THE RIDGE WILL BECOME ESTABLISHED ALONG 28N BY EARLY SUN THEN WILL LIFT N TO ALONG 29N/30N BY EARLY NEXT WEEK AS A TROPICAL WAVE APPROACHES THE FAR SE PORTION FROM THE TROPICAL N ATLC WATERS BY LATE MON. CARIBBEAN SEA AND TROPICAL N ATLC... AS MENTIONED ABOVE...THE ENERGETIC TROPICAL WAVE HAS PUSHED INTO THE NW CARIBBEAN EXTENDING FROM W CUBA TO THE SW CARIB JUST E OF 80W. DEEP LAYERED E TO SE FLOW N OF 18N IS HELPING TO MAINTAIN STRONG CNVTN NEAR AND BEHIND THE WAVE...WITH THE STRONG MID LEVEL WIND SURGE BEHIND THE WAVE CURRENTLY MOVING FROM THE JAMAICA AREA NW TO THE W TIP OF CUBA. ABUNDANT MOISTURE BEHIND THE WAVE IS ALSO BEING PULLED OFF OF COLOMBIA AND INTO THE SW GULF WHERE ACTIVE CNVTN WILL ALSO CONTINUE TODAY. E-SE WINDS OF 20 KT WITH POCKETS TO 25 KT WILL SPREAD NW BEHIND THE WAVE FROM THE W OF 70W INTO THE NW CARIB TODAY...PUMPING UP SEAS 6-7 FT AND LOCALLY TO 8 FT. STRONG GUSTY WINDS AND FREQUENT LIGHTNING ARE TO BE EXPECTED. AS THE WAVE MOVE INTO THE YUCATAN TONIGHT WINDS AND SEAS WILL BEGIN TO GRADUALLY SUBSIDE ACROSS THE BASIN FROM 70-75W OVERNIGHT AND THEN E OF 78W FRI. EASTERLY TRADES WILL INCREASE BACK TO 20 KT IN THE S CENTRAL CARIBBEAN SAT THROUGH MON AS THE PRES GRADIENT INCREASES DUE TO BUILDING ATLC RIDGING NE OF THE LEEWARD ISLANDS. IN THE TROPICAL N ATLC...NE-E WINDS OF 10-15 KT DOMINATE THE REGION WITH HIGH PRES LOCATED NW OF THE WATERS AND A WEAK AND BROAD LOW TO MID LEVEL TROUGH TO THE NE ALONG ABOUT 50W. THE TROUGH WILL MOVE W INTO E PORTIONS THIS AFTERNOON AND TONIGHT WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING AHEAD OF IT AS IT INTERACTS WITH A LARGE TUTT LOW TO THE NE OF THE LEEWARDS. A WEAKENING TROPICAL WAVE ACROSS THE E CENTRAL ATLC WILL REACH NEAR SUN MORNING AND MOVE ACROSS THE WATERS SUN. A SECOND TROPICAL WAVE FOLLOWING THIS FIRST WAVE WILL HAVE MOVED VERY CLOSE BEHIND THE FIRST WAVE AND MOVE INTO THE WATERS SUN AFTERNOON. A MODEST LLVL WIND SURGE WILL ACCOMPANY THIS TANDEM OF WAVES...BUT THE SECOND WAVE WILL BE VERY ENERGETIC AND KICK OFF VERY ACTIVE CNVTN SUN AFTERNOON AND NIGHT AS IT MOVES ACROSS THE N HALF OF THE AREA. GLOBAL MODEL GUIDANCE CONTINUES TO SUGGEST THE POSSIBILITY OF THE NEXT OR THIRD TROPICAL WAVE DEVELOPING INTO A TROPICAL CYCLONE AS IT APPROACHES THE AREA. WE ARE QUICKLY APPROACHING THE PEAK OF HURRICANE SEASON AND THIS SCENARIO IS CERTAINLY IN LINE WITH CLIMATOLOGY. WARNINGS... SW N ATLC... .NONE. CARIBBEAN... .NONE. .GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING