000 AGXX40 KNHC 160748 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 345 AM EDT FRI AUG 16 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: MEDIUM RANGE FORECAST POSITIONS USED FOR DEVELOPING LOW PRES WITH 10-M WINDS CAPPED AT 25-30 KT. WILL BUILD SEAS HIGHER THAN GUIDANCE IN RELATION TO LOW OVER MUCH OF THE WESTERN PORTION OF THE GULF. OTHERWISE PREVIOUS FORECAST BLENDED WITH LATEST GFS. LOW CONFIDENCE THROUGHOUT. A SURFACE RIDGE EXTENDS FROM CENTRAL FLORIDA TO THE CENTRAL TEXAS COAST. A TROPICAL WAVE IS ANALYZED FROM 25N90W TO INLAND THE YUCATAN PENINSULA WITH A 1010 MB LOW PRES ON THE WAVE NEAR 21N90W. THE LOW IS FORECAST TO MOVE OFFSHORE THE YUCATAN PENINSULA TO NEAR 91W LATER THIS MORNING...THEN TO NEAR 22N92W BY LATE TONIGHT...TO NEAR 23N93W BY EARLY SAT...TO NEAR 24N93W BY LATE SAT...AND NW ACROSS THE NW GULF THROUGH MON. THE LOW MAY MOVE INLAND FAR NE TEXAS OR SW LOUISIANA LATE MON INTO TUE...WITH THE POSSIBILITY OF TROPICAL CYCLONE FORMATION. FORECAST CONFIDENCE REMAINS WITH LOW CONCERNING THE DEVELOPMENT...TRACK...AND ULTIMATE IMPACTS OF A LOW PRES SYSTEM IN THE SOUTHERN GULF FRI THROUGH SUN. OFFICIAL WINDS HAVE CAPPED AT 25-30 KT WITH SEAS NO HIGHER THAN 11 FT-12 FT. MOST GUIDANCE SHOWS THE RIDGING BUILDING ACROSS THE NORTHERN GULF IN THE WAKE OF THE LOW/TROUGH EARLY NEXT WEEK. WILL MAKE ONLY MINOR TWEAKS TO CURRENT GRID FORECAST OF WINDS AND SEAS IN THE FAR NW GULF FOR SAT THROUGH TUE. ...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 18N BETWEEN 69W AND 80W. THESE TRADES ARE THE RESULT OF HIGH PRES BUILDING N OF THE AREA INTO THE CARIBBEAN IN THE WAKE OF THE ABOVE MENTIONED TROPICAL WAVE. ALTIMETER DATA FROM YESTERDAY ALONG WITH BUOY AND SHIP OBSERVATIONS INDICATE WAVE HEIGHTS REACHING 8 TO 11 FT IN THE SOUTH-CENTRAL CARIBBEAN. MODERATE TRADES COVER THE EASTERN CARIBBEAN WITH SEAS OF 5 TO 7 FT OUTSIDE OF THE LEE OF THE ISLANDS. MODERATE TO FRESH E TO SE WINDS ARE NOTED OVER THE WESTERN CARIBBEAN. AS MENTIONED IN PREVIOUS FORECASTS...THE TRADE WINDS OVER THE S/CENTRAL CARIBBEAN WILL DIMINISH THROUGH SAT AS A TROPICAL WAVE CURRENTLY OVER THE LESSER ANTILLES MOVING W AT 10-15 KT MOVES THROUGH THE EASTERN CARIBBEAN. THIS WAVE IS FORECAST TO REACH NEAR 69W TONIGHT...TO NEAR 72W BY SAT EVENING ...AND THEN THE WESTERN CARIBBEAN BY LATE SUN. GUIDANCE SUGGESTS THAT THIS WAVE WILL GRADUALLY BECOME DIFFUSE AT THE SURFACE AS IT MOVES THROUGH WESTERN CARIBBEAN. IN THE WAKE OF THE WAVE...NE WINDS TO 25 KT ARE POSSIBLE OFF THE COAST OF COLOMBIA THROUGH THE WEEKEND PARTICULARLY IN THE OVERNIGHT AND EARLY MORNING HOURS. LOOKING AHEAD...THE ATLC RIDGE WEAKENS FURTHER AS ANOTHER TROPICAL WAVE APPROACHES FROM THE E. TRADES RESPOND BY WEAKENING FURTHER EARLY NEXT WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH LATEST GFS WITH HIGH CONFIDENCE. THE 0600 UTC SURFACE ANALYSIS HAS THE ATLC RIDGE EXTENDING FROM NEAR 31N58W SW TO S FLORIDA. THE MOST RECENT ASCAT PASS SHOWED S- SW WINDS OF 10-15 KT ACROSS THE NW PORTION OF THE ARE...WHILE NE- E WINDS OF 15-20 KT WERE S OF 23N E OF 63W DUE TO A TIGHT PRES GRADIENT ALONG THE NORTHERN PORTION OF THE CARIBBEAN SEA TROPICAL WAVE ACROSS THE LESSER ANTILLES. A WEAK STATIONARY FRONTAL BOUNDARY IS JUST INLAND NORTHERN FLORIDA AND SE LOUISIANA...WHILE A TROUGH EXTENDS FROM JUST S OF IT SW TO NEAR 26N96W. SEAS OF 2 TO 4 FT ARE NOTED W OF 65W...WITH 4 TO 6 FT IN NE AND E SWELL ACROSS AMZ127 NE OF THE LEEWARD ISLANDS. THE RIDGE AXIS WILL LIFT N THROUGH TUE...ALLOWING FOR GENERALLY LIGHT WINDS TO CONTINUE OVER MUCH OF THE AREA...EXCEPT IN THE FAR SOUTHERN PORTION WHERE MODERATE TO FRESH WINDS WILL CONTINUE AS THE NORTHERN PORTION OF THE TROPICAL WAVE PUSHES W ACROSS THOSE WATERS. A SECOND TROPICAL WAVE WILL FOLLOW APPROACHING THE LEEWARD ISLANDS BY EARLY SUN...AND SWEEPING S OF THE AREA THROUGH MON. LOOKING FURTHER AHEAD TO NEXT WEEK...TROPICAL STORM ERIN IS FORECAST TO MOVE WNW FOR THE NEXT COUPLE OF DAYS REACHING 35.5W AS A TROPICAL STORM BY EARLY SAT. FOR MORE INFORMATION ON THIS SYSTEM...PLEASE SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS...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 AGUIRRE. NATIONAL HURRICANE CENTER.