000 AGXX40 KNHC 200733 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 333 AM EDT SAT JUL 20 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: GFS/ECMWF/OFFICIAL BLEND WITH GOOD CONFIDENCE. NWPS FOR WAVE HEIGHTS. RIDGING ALOFT OVER CENTRAL MEXICO IS BLOCKING THE WESTWARD PROGRESS OF AN UPPER LOW CENTERED OVER LOUISIANA. AS A RESULT...A SURFACE TROUGH EXTENDING FROM THE MISSISSIPPI DELTA TO NE MEXICO IS MAKING SLOWER WESTWARD PROGRESS THAN EXPECTED EARLIER. IN ADDITION...BECAUSE THE UPPER LOW HAS NOT MOVED OVER THE PAST 12 TO 24 HOURS...CONVECTION HAS REMAINED ACTIVE ACROSS MUCH OF THE CENTRAL AND NE GULF...IN THE DIVERGENT FLOW ALOFT OF THE SE QUADRANT OF THE UPPER LOW. THIS CONVECTION HAS SUBSIDED FOR THE MOST PART IN THE PAST SEVERAL HOURS...BUT NEW CONVECTION IS FLARING IN THE YUCATAN CHANNEL ASSOCIATED WITH THE NORTHERN PORTION OF TROPICAL WAVE MOVING THROUGH THE NW CARIBBEAN. LIGHT TO MODERATE WINDS PREVAIL ACROSS THE GULF CURRENTLY...WITH THE HIGHEST WINDS AROUND 15 KT OVER THE N CENTRAL GULF BETWEEN THE SURFACE TROUGH AND A RIDGE EXTENDING FROM THE WESTERN ATLC ACROSS FLORIDA TO THE EASTERN GULF. SEAS REMAIN 2 TO 3 FT OVERALL. THROUGH SUN...THE UPPER LOW WILL GRADUALLY DRIFT NW AND WEAKEN...ALLOWING THE SURFACE TROUGH TO DRIFT INTO THE FAR NW GULF AND DAMPEN OUT AS THE ATLC RIDGE EXTENDS ALONG ROUGHLY 28N ACROSS THE GULF. LIGHT TO MODERATE FLOW WILL CONTINUE ACROSS THE GULF THROUGH EARLY NEXT WEEK UNDER THE INFLUENCE OF THE RIDGE. WINDS WILL OCCASIONALLY REACH 20 KT OFF THE WEST COAST OF YUCATAN AND THE SW GULF IN THE OVERNIGHT HOURS. SEAS WILL REMAIN 4 FT OR LESS EXCEPT TO 6 FT IN THE SW GULF. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC... MODEL PREFERENCE: GFS/ECMWF/OFFICIAL BLEND WITH GOOD CONFIDENCE. NWPS FOR WAVE HEIGHTS OVER CARIBBEAN BASIN. A TROPICAL WAVE HAS MOVED W THROUGH THE GULF OF HONDURAS INTO NORTHERN CENTRAL AMERICA. ANOTHER TROPICAL WAVE BETWEEN EASTERN CUBA AND PANAMA IS ENTERING THE WESTERN CARIBBEAN. A THIRD TROPICAL WAVE IS WELL E OF THE AREA IN THE ATLC ALONG 45W. IN BETWEEN...A RIDGE EXTENDING FROM 1022 MB HIGH PRES N OF THE AREA IS ALLOWING A BROAD SWATH OF 20 TO 25 KT TRADE WINDS FROM THE TROPICAL N ATLC W OF 55W THROUGH THE CENTRAL CARIBBEAN. SCATTEROMETER DATA SHOW WINDS TO 30 KT OFF THE COAST OF COLOMBIA. SEAS WERE REPORTED NEAR 11 FT NEAR BUOY 42048 AT 15N75W...AND ARE LIKELY REACHING AS HIGH AS 13 FT BETWEEN THE BUOY AND COLOMBIA. CONVECTION IS FLARING BETWEEN THE WESTERNMOST TROPICAL WAVES OVER THE NW CARIBBEAN. WINDS WILL START TO INCREASE TONIGHT AND THROUGH SUN OVER THE GULF OF HONDURAS AFTER THE SECOND WAVE PASSES. ELSEWHERE CONDITIONS WILL PERSIST INTO MON. LOOKING AHEAD...THE TROPICAL WAVE OVER THE ATLC WILL APPROACH THE EASTERN CARIBBEAN BY LATE SUN...AND INTO THE CENTRAL CARIBBEAN BY LATE MON. WINDS WILL DIMINISH SLIGHTLY OVER THE CENTRAL CARIBBEAN AS THE WAVE APPROACHES...WITH SEAS SUBSIDING TO 8 FT OVER THE SW CARIBBEAN BY TUE. GLOBAL MODELS SHOW THE RIDGE N OF THE AREA WEAKENING BY MID WEEK...AND THUS DO NOT INDICATE A RETURN THE STRONG TRADES IN THE WAKE OF THIS THIRD TROPICAL WAVE. ...SW N ATLANTIC W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: GFS/ECMWF/OFFICIAL BLEND WITH GOOD CONFIDENCE. A STRONG RIDGE REMAINS ANCHORED E TO W ALONG 28N. THE NORTHERN PORTION OF A TROPICAL WAVE HAS SPLIT OFF FROM THE MAIN WAVE IN THE CARIBBEAN AND IS TRAVELING AROUND THE PERIPHERY OF THE RIDGE THROUGH THE CENTRAL BAHAMAS TOWARD THE CAY SAL/STRAITS OF FLORIDA AREA. AN ASCAT PASS FROM 0230 UTC INDICATED WINDS OF 20 TO 25 KT BEHIND THE WAVE OFF THE NW COAST OF HISPANIOLA TOWARD THE ENTRANCE TO THE WINDWARD PASSAGE. ELSEWHERE GENERALLY LIGHT TO MODERATE WINDS PERSIST S OF THE RIDGE AXIS...WITH NEARLY CALM WINDS NEAR THE CENTER OF THE HIGH PRES N OF 24N E OF 75W. S TO SW FLOW TO 15 KT CAN BE EXPECTED W OF 75W TO THE NE FLORIDA COAST THROUGH MON BETWEEN THE HIGH PRES AND TROUGHING OVER THE SE UNITED STATES. THESE WINDS WILL INCREASE TUE INTO WED IN RESPONSE TO A DEEPENING TROUGH OVER VIRGINIA AND THE CAROLINAS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.