000 AGXX40 KNHC 121646 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1246 PM EDT WED AUG 12 2015 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 BLENDED/ECMWF BLEND. TAFB NWPS USED FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD WITH MANUAL ADJUSTMENTS TO MATCH OBSERVATIONS. MEDIUM-HIGH CONFIDENCE. AN INVERTED THERMAL TROUGH WILL DEVELOP EACH AFTERNOON OVER THE YUCATAN PENINSULA...AND THEN MOVE W-NW ACROSS THE SW GULF WATERS GENERALLY TO THE S OF 22N BETWEEN 90-93W DURING THE EVENING THROUGH LATE NIGHT HOURS...REACHING ALONG 94-95W DURING THE EARLY DAYLIGHT HOURS...AND THEN DISSIPATING BY EARLY AFTERNOON. EXPECT THIS TROUGH TO BE ACCOMPANIED BY A NE-E 15-20 KT WIND SHIFT THIS EVENING...THEN ONLY A 10-15 KT WIND SHIFT WITHIN ABOUT 120 NM OF THE TROUGH AXIS ON THU-SUN NIGHTS...WITH GUIDANCE HINTING AT ANOTHER 15-20 KT EVENT ON MON NIGHT. AN E TO W RIDGE EXTENDS ELSEWHERE ACROSS THE S GULF FROM SW FL TO SE TX WITH A SURFACE HIGH DEVELOPING INTERMITTENTLY ALONG THE RIDGE AXIS OVER THE FAR SE PORTION. GENERALLY EXPECT 5-10 KT ANTICYCLONIC FLOW WITHIN ABOUT 150 NM OF THE RIDGE. A WEAK PRE- FRONTAL TROUGH HAS MOVED INTO THE N-CENTRAL GULF AS EXPECTED AND IS ACCOMPANIED BY SCT RW/ISOL TS WHICH IS DEPICTED IN THE WEATHER GRIDS THROUGH TONIGHT. A WEAK COLD FRONT TRAILS BY ABOUT 150 NM AND WILL SWEEP INTO THE N-CENTRAL WATERS THIS EVENING MERGING WITH THE PRE-FRONTAL TROUGH WITH THE MERGED BOUNDARY CONTINUING E TONIGHT. THE FRONT WILL STALL FROM THE FL PANHANDLE TO THE N-CENTRAL WATERS ON THU. EXPECT A WEAK LOW TO FORM ALONG THE FRONTAL TROUGH ON THU NIGHT AND DRIFT SLOWLY W ON FRI- SUN...BUT ONLY ACCOMPANIED BY 5-10 KT CYCLONIC FLOW. A RIDGE WILL REESTABLISH ACROSS THE NORTHERN GULF SUN NIGHT AND MON. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS BLENDED/ECMWF BLEND. TAFB NWPS USED FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD WITH MANUAL ADJUSTMENTS TO MATCH OBSERVATIONS. MEDIUM-HIGH CONFIDENCE. ATLC RIDGE N OF THE AREA COMBINED WITH LOW PRESSURE OVER NW COLOMBIA WILL CONTINUE TO ENHANCE FRESH TO LOCALLY STRONG NOCTURNAL TRADES WITHIN ABOUT 240 NM OF THE COLOMBIAN COAST AND ALONG THE FAR NW COAST OF VENEZUELA AS WELL. A TROPICAL WAVE OVER THE CENTRAL CARIBBEAN WILL CONTINUE W AT ABOUT 18 KT AND PASS THROUGH THE W CARIBBEAN ON THU NIGHT THROUGH FRI NIGHT. ONLY A SLIGHT ENHANCEMENT TO CONVECTION IS CURRENTLY NOTED. A SECOND TROPICAL WAVE...CURRENTLY ALONG 48W WILL CONTINUE W AT 15 KT PASSING 55W ON THU AND PASS THROUGH THE E CARIBBEAN ON FRI-SAT...REACHING THE CENTRAL CARIBBEAN LATE IN THE WEEKEND. UPPER SUBSIDENCE IS CURRENTLY SUPPRESSING CONVECTION TO ONLY A FEW INTERMITTENT CLUSTERS AND LITTLE CHANGE EXPECTED TILL THE WAVE REACHES THE E CARIBBEAN. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GFS/ECMWF BLEND. TAFB NWPS USED FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD WITH MANUAL ADJUSTMENTS TO MATCH OBSERVATIONS MEDIUM-HIGH CONFIDENCE. AN UPPER LEVEL TROUGH HAS MEAN AXIS N OF 29N ALONG 79W AND IS ENHANCING CONVECTION ACROSS THE WATERS N OF 27N BETWEEN 67-69W AND WILL BE DENOTED IN THE WEATHER GRIDS THIS AFTERNOON AND TONIGHT. AN ATLC SURFACE RIDGE EXTENDING NE-SW FROM 31N64W TO EXTREME SE FL WILL CONTINUE TO SHIFT N TONIGHT REACHING FROM 31N66W TO PORT EVERGLADES FL ON THU...FROM BERMUDA TO FT PIERCE FL ON FRI...AND FROM BERMUDA TO PORT CANAVERAL FL ON SAT. A WEAK COLD FRONT WILL MOVE OFFSHORE NE FL TONIGHT...THEN IMMEDIATELY STALL AND MEANDERING ACROSS THE FAR NW WATERS THROUGH FRI...THEN MOVE NW ON SAT AS THE RIDGE SHIFTS FURTHER N. WHATEVER REMAINS OF THE FRONTAL TROUGH SHOULD MOVE INLAND ON SAT NIGHT INTO SUN. MODERATE E-SE TRADES ARE OBSERVED S OF THE RIDGE...EXCEPT INCREASING TO FRESH ALONG THE N COAST OF HISPANIOLA ON SAT AND SUN EVENINGS WHEN THE RIDGE HAS MOVED N OF 28N. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER NELSON. NATIONAL HURRICANE CENTER.