000 AGXX40 KNHC 290638 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 238 AM EDT WED APR 29 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: 00Z GFS BLENDED WITH PREVIOUS OFFICIAL THROUGH SAT NIGHT. 12Z ECMWF BLENDED WITH PREVIOUS OFFICIAL SUN AND SUN NIGHT. TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL SEAS THROUGH SAT NIGHT. EC WAVE BLENDED WITH PREVIOUS OFFICIAL SUN AND SUN NIGHT. MEDIUM CONFIDENCE. THE 0026 UTC RAPIDSCAT PASS SHOWS FRESH TO STRONG WINDS BEHIND THE COLD FRONT IN THE W GULF...WITH WINDS TO 30 KT OFFSHORE OF TAMPICO. THE GLOBAL MODELS ARE TOO WEAK HERE...WITH THE 00Z GFS MORE CLOSELY CAPTURING THE WIND FIELD THAN THE 12Z ECMWF. WINDS WERE BEEFED UP HERE AND IN THE USUAL TOPOGRAPHICALLY ENHANCED REGION IN THE SW GULF TODAY. THE GENERAL TREND IN THE MODELS THE LAST FEW DAYS HAS BEEN TOWARD LESS DEVELOPMENT OF THIS SYSTEM AS IT MOVES INTO THE ATLC ON WED. THIS HAS LEAD TO WEAKER WINDS IN THE EASTERN GULF WED BEHIND THE FRONT. THE FORECAST WAS ADJUSTED TOWARD THE GFS TO ACCOUNT FOR THIS. MORE SIGNIFICANT DIFFERENCES BEGIN TO ARISE BY SUN WHEN THE MODELS AGREE ON CARRYING AN UPPER TROUGH INTO THE NW GULF AND BEGIN TO AMPLIFY IT AS IT TRACKS EASTWARD. THE GFS IS A MORE AMPLIFIED SOLUTION THAN THE ECMWF ON SUN AND IT BECOMES A STRONG OUTLIER WITH THE SYSTEM...ESPECIALLY AS IT MOVES INTO THE ATLC JUST N OF THE BAHAMAS ON TUE. THE GFS GENERATES STRONGER TRADE WINDS IN THE STRAITS OF FLORIDA SUN IN RESPONSE TO THE DEEP LAYER RIDGING IT BUILDS AHEAD OF THIS SYSTEM. BELIEVE IT IS A BIT OVERDONE...SO THE FORECAST WAS ADJUSTED TOWARD THE ECMWF BY SUN. THE PREVIOUS OFFICIAL FORECAST WAS BLENDED WITH THE NWPS FOR SEAS...WITH THE EC WAVE RELIED ON TO ADJUST THE FORECAST ON SUN AND SUN NIGHT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z ECMWF BLENDED WITH PREVIOUS OFFICIAL. TAFB NWPS FOR SEAS. MEDIUM CONFIDENCE. BOTH THE GFS AND 12Z ECMWF AGREE ON CARRYING THE COLD FRONT FROM THE GULF OF MEXICO INTO THE YUCATAN CHANNEL LATE WED. THEY HAVE BOTH BACKED OFF ON THE STRENGTH AND THE EASTERN PUSH OF THE FRONT. THEY NOW AGREE TO KEEP THE FRONT OVER THE NW CARIBBEAN WHERE IT WILL DISSIPATE SAT AND THEN RETURN W AS A TROUGH SUN. THE 12Z ECMWF HAS THE EDGE AT THIS POINT AS IT IS PREFERRED WITH THE PATTERN OVER THE GULF OF MEXICO AS EXPLAINED ABOVE. THE PRESSURE GRADIENT HAS BUILT OVER THE S CENTRAL AND SE CARIB BETWEEN THE SUBTROPICAL RIDGE AND LOWER PRES IN THE WESTERN CARIB ASSOCIATED WITH THE APPROACHING COLD FRONT. AN AREA OF FRESH TO STRONG TRADES IS EXPECTED TO PERSIST THROUGH FRI MORNING PRIMARILY OFF THE N CENTRAL AND NW COAST OF VENEZUELA. WINDS SHOULD DIMINISH LATE FRI AS THE SUBTROPICAL RIDGE IS FORCED E BY THE COLD FRONT IN THE SW N ATLC...WITH FRESH TO STRONG TRADES RETURNING ALONG THE COAST OF COLOMBIA IN THE OVERNIGHT/EARLY MORNING HOURS DURING THE WEEKEND AND ALONG THE S CENTRAL CARIB SUN NIGHT AS HIGH PRES BUILDS BEHIND THE FRONT IN THE SW N ATLC AND THEN IN THE CENTRAL ATLC AND THE FRONT TO THE N WEAKENS. THE TAFB NWPS LOOKED REASONABLE TO BLEND WITH THE PREVIOUS SEAS FORECAST. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12Z ECMWF BLENDED INCREASINGLY WITH PREVIOUS OFFICIAL FORECAST THROUGH SUN NIGHT. EC WAVE AND TAFB NWPS FOR SEAS. LOW CONFIDENCE. AS MENTIONED IN THE GULF OF MEXICO SECTION...THE GENERAL TREND IN THE MODELS THE LAST FEW DAYS HAS BEEN TOWARD LESS DEVELOPMENT OF THE LOW IN THE GULF OF MEXICO AS IT MOVES INTO THE ATLC ON WED/THU. CONFIDENCE IS LOW IN THE DETAILS FOR THIS SYSTEM AS THE MODELS CONTINUE TO BOUNCE BACK AND FORTH ON THE TRACK AND INTENSITY OF THE LOW. THEREFORE...STUCK PRIMARILY TO THE PREVIOUS FORECAST EARLY IN THE PERIOD AND BLENDED MORE 12Z ECMWF IN THROUGH SUN NIGHT AS THE RIDGE AHEAD OF THE UPPER TROUGH MOVING INTO THE GULF OF MEXICO APPEARS TO BE TOO AMPLIFIED IN GFS. DETAILS WITH THIS SYSTEM ARE DISCUSSED IN THE GULF OF MEXICO SECTION. BEYOND THE FORECAST PERIOD...THE 00Z GFS BECOMES A SIGNIFICANT OUTLIER AS THE TROUGH MOVES INTO THE ATLC JUST N OF THE BAHAMAS ON TUE. THE TAFB NWPS AND EC WAVE WERE BLENDED WITH THE PREVIOUS OFFICIAL FORECAST FOR SEAS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 SCHAUER. NATIONAL HURRICANE CENTER.