000 AGXX40 KNHC 170700 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 300 AM EDT Sat Jun 17 2017 Marine Weather Discussion for the Gulf of Mexico, Caribbean Sea, and Tropical North Atlantic from 07N to 19N between 55W and 64W and the Southwest North Atlantic including the Bahamas ...GULF OF MEXICO... High pressure is centered over the Gulf waters. Latest satellite derived winds and seas along with ship, buoy, and CMAN data depict light to gentle winds over the area with seas in the 1 to 2 ft range over the eastern Gulf and 2 to 3 ft over the western Gulf. Confidence remains high in the development of a large cyclonic gyre developing over Central America over the next day or so. There remains uncertainty with the overall structure, strength, and location of the feature as the forecast evolves over the weekend into early next week. The latest model guidance has come into somewhat better agreement with the track of the low into the southwestern Gulf. However, there continues to be a difference in strength of the low, with the ECMWF still the strongest. There is currently a high chance that this low will develop into a tropical cyclone over the next 5 days. Regardless of tropical cyclone development, this system will impact the area with strong winds and building seas likely over much of the Gulf early next week, accompanied by very active and widespread showers and thunderstorms. The rainfall associated to this system will also impact portions of Central America, the Yucatan Peninsula, and western Cuba, with flash flooding and mudslides possible over prone areas. Expect seas to begin to build over Yucatan Channel and far south-central waters beginning on Sunday, and continue to through next week over much of the central and western Gulf waters as well following the ECMWF guidance. Interests in the southern Gulf, and surrounding land masses, should monitor the Tropical Weather Outlook for the latest information on this evolving weather scenario. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Latest satellite derived winds and seas along with ship, buoy, and CMAN data depict moderate to fresh winds over the central Caribbean, moderate winds over the eastern Caribbean, gentle to moderate winds over the western Caribbean, and gentle to moderate winds over the tropical north Atlantic forecast zones. Seas are in the 5 to 7 ft range over the central Caribbean, 3 to 5 ft over the eastern and western Caribbean, and 4 to 6 ft over the tropical north Atlantic forecast zones. Active convection that earlier was noted over the western Caribbean has shifted to the central Caribbean for the time being as abundant tropical moisture converges as a large cyclonic gyre is slowly evolving over Central America. Recent satellite imagery is revealing developing strong convection over and within 60 nm northeast of the coast of NE Honduras. A close look at the shortwave infra-red imagery suggests that an elongated northeast to southwest cyclonic circulation is becoming apparent just to the west of this convection. In addition, the 0326Z Ascat pass from late last night revealed a northeast to southeast wind shift across a trough axis roughly along 85W south of 21N. A tropical wave over the central Caribbean will become absorbed into this evolving gyre by Sunday. Strong winds will cover most of the northwest Caribbean Sunday night into Monday as the broad low moves through the Yucatan peninsula. Seas will build to 8 to 14 ft, with highest seas in the Yucatan Channel. This will be accompanied by a large area of thunderstorms and squalls. This band of winds and seas will shift westward through middle part of the upcoming week. There is currently a high chance that this low will develop into a tropical cyclone over the next 5 days. Regardless of tropical cyclone development, this system will impact the area with strong winds and building seas over the northwestern Caribbean this weekend into early next week, accompanied by very active and widespread weather. The rainfall associated to this system will also impact portions of Central America, the Yucatan Peninsula, and western Cuba, with flash flooding and mudslides possible over prone areas. Interests in the western Caribbean, and surrounding land masses, should monitor the Tropical Weather Outlook for more information. Outside of this area, building high pressure over the western Atlantic in the wake of the broad cyclonic gyre or developed low pressure will support increasing trade winds and building seas over much of the central and eastern Caribbean early next week and through middle part of the week. Farther east, an active tropical wave will bring increased winds, seas and convection into the waters east of the Windward Islands early next week. ...SW N ATLANTIC INCLUDING THE BAHAMAS... High pressure prevails over the forecast waters. Latest satellite derived winds and seas along with ship, buoy, and CMAN data depict gentle to locally moderate winds over the far southern waters with light to gentle winds prevailing elsewhere. Seas are in the 3 to 4 ft range outside the Bahamas, and 1 to 2 ft west of the Bahamas. The high pressure ridge will prevail through the forecast period. Winds will increase over the southwest waters during the weekend as the pressure gradient tightens between the ridge and the developing Central America gyre. These winds and seas are expected to gradually decrease beginning on Tuesday as the culprit gradient slackens. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.nhc.noaa.gov/marine $$ .Forecaster Aguirre. National Hurricane Center.