000 AGXX40 KNHC 171837 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 237 PM EDT SAT AUG 17 2013 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: MODELS ARE IN GENERAL AGREEMENT KEEPING A BROAD LOW/TROUGH FEATURE ACROSS THE GULF WATERS. PREVIOUS FORECAST BLENDED WITH LATEST GFS. AVERAGE CONFIDENCE THROUGH NEXT 48 HOURS WITH LOW/TROUGH FEATURE. HIGH CONFIDENCE REMAINDER OF FORECAST PERIOD. A 1010 MB WEAK LOW PRES (AL92) REMAINS OVER THE SW GULF WITH A TROUGH EXTENDING NORTHWARD TO NEAR SE LOUISIANA. AN EARLIER SCATTEROMETER PASS CLEARLY CAPTURED THE WEAK CYCLONIC CIRCULATION ASSOCIATED WITH THE LOW AS WELL THE NE TO SE WIND SHIFT ACROSS THE TROUGH. A BAND OF SHOWERS AND TSTMS IS NOTED EAST OF THE TROUGH AXIS. WINDS AND SEAS WILL BE HIGHER ALONG THIS CONVECTIVE BAND...PARTICULARLY NEAR THE TSTMS. IN FACT...A RECENT HIGH RESOLUTION ASCAT PASS INDICATES FRESH TO STRONG SLY WINDS ACROSS THE CENTRAL GULF BETWEEN THE TROUGH AND A RIDGE COVERING THE EASTERN GULF WATERS. THE LOW PRES IS FORECAST TO CONTINUE TO MOVE IN A WNW DIRECTION REACHING NEAR 21.5N94.5 EARLY SUN MORNING AND NEAR 22N96W EARLY MON MORNING...THEN IT IS EXPECTED TO BECOME AN OPEN TROUGH VERY CLOSE TO THE COASTS OF SE TEXAS AND NE MEXICO MON NIGHT OR EARLY TUE. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN ONLY MARGINALLY CONDUCIVE FOR DEVELOPMENT OVER THE NEXT COUPLE OF DAYS. AFTER 48 HOURS...DEVELOPMENT IS LESS LIKELY DUE TO INTERACTION WITH LAND. INTERESTS IN THE CENTRAL AND WESTERN GULF OF MEXICO SHOULD MONITOR THE PROGRESS OF THE SYSTEM THROUGH EARLY NEXT WEEK. THE NEW FORECAST PACKAGE WILL REFLECT A LOWER TREND WITH RESPECT TO WINDS AND SEAS BASED ON CURRENT AVAILABLE DATA. A WEAK COLD FRONT HAS ENTERED THE NW GULF...AND IS EXPECTED TO BECOME NEARLY STATIONARY OVER THE NW GULF TONIGHT. HIGH PRES RIDGING WILL BUILD WESTWARD FROM ATLC ACROSS THE NORTHERN WATERS ONCE THE LOW/TROUGH MOVES INLAND WITH GENERALLY LIGHT WINDS AND LOW SEAS THROUGHOUT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH LATEST GFS. HIGH CONFIDENCE. THE MAIN ISSUE IN THE SHORT TERM IS THE NE TO E 20-25 KT TRADES LOCATED OVER THE S CENTRAL CARIBBEAN SEA FROM 11N TO 14N BETWEEN 72W AND 75W. AN EARLIER ASCAT PASS CONFIRMED THE PRESENCE OF THESE WIND SPEEDS. THESE TRADES ARE THE RESULT OF A TIGHT PRES GRADIENT THERE. SEAS ASSOCIATED WITH THESE TRADES ARE NEAR 8 FT. ELSEWHERE...LIGHTER TRADES CAN BE FOUND WITH SPEEDS OF 10-15 KT EXCEPT IN THE GULF OF HONDURAS WHERE E-SE WINDS OF 20-25 KT ARE OCCURRING WITH SEAS OF ABOUT 5-8 FT MAINLY AT NIGHT. NE WINDS OF 20-25 KT ALSO WERE NOTED ACROSS THE WINDWARD PASSAGE WITH SEAS BELOW 8 FT. THESE GENERAL CONDITIONS ARE EXPECTED TO PERSIST TO ABOUT 24 HOURS...THEN WINDS AND SEAS WILL DIMINISH ACROSS THE CENTRAL CARIBBEAN AS A TROPICAL WAVE CURRENTLY ALONG 71W MOVES ACROSS THE AREA. THE GRADIENT SHOULD RELAX EVEN MORE MON AS A TROPICAL WAVE CURRENTLY OVER THE EASTERN TROPICAL N ATLC NEAR 56W ENTERS THE EASTERN CARIBBEAN EARLY ON SUN. THIS WAVE IS FORECAST TO MOVE ACROSS THE EASTERN CARIBBEAN SUN AND MON...AND THE CENTRAL CARIBBEAN TUE AND WED. IN THE WAKE OF THIS WAVE...EXPECT NE WINDS OF 20-25 KT IN THE FAR SW CARIBBEAN SEA NEAR THE COAST OF COLOMBIA. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH LATEST GFS WITH HIGH CONFIDENCE. A RIDGE EXTENDS FROM NEAR BERMUDA TO S FLORIDA. THIS RIDGE WILL LIFT N TO NEAR 31N TODAY AND SUN...AND TO N OF THE AREA EARLY NEXT WEEK. UNDER THE INFLUENCE OF THIS RIDGE...EXPECT MAINLY A MODERATE E-SE WIND FLOW WITH SEAS IN THE 4 TO 6 FT RANGE E OF THE BAHAMAS. THE EXCEPTION WILL BE S OF 22N WHERE WINDS WILL BE OCCASIONALLY 20-25 KT WITH SEAS TO NEAR 7 OR 8 FT AS TROPICAL WAVES MOVE WESTWARD ACROSS THOSE WATERS. THE FIRST WAVE...IS CURRENTLY ALONG 71W MOVING W NEAR 20 KT. THIS WAVE WILL MOVE ACROSS THE FAR SOUTHERN WATERS THROUGH SUN. A SECOND TROPICAL WAVE WILL FOLLOW APPROACHING THE LEEWARD ISLANDS BY EARLY SUN...AND SWEEPING S OF THE AREA THROUGH TUE. TROPICAL STORM ERIN IS FORECAST TO SLOWLY WEAKEN OVER THE NEXT DAY OR TWO. THE OFFICIAL FORECAST CALLS FOR ERIN TO BECOME AGAIN A TROPICAL DEPRESSION TONIGHT. IT WILL MOVE NORTHWEST AT 10 KT REACHING NEAR 39W EARLY SUN MORNING...AND NEAR 43W BY EARLY MON. FOR MORE INFORMATION ON THIS SYSTEM...PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC...FOUND AT HTTP://WWW.HURRICANES.GOV. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER GR. NATIONAL HURRICANE CENTER.