420 AXNT20 KNHC 151009 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT Sun Jul 15 2018 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... The center of Subtropical storm Beryl at 15/0600 UTC is near 38.3N 65.2W, or about 360 nautical miles north of Bermuda, or about 385 nautical miles south of Halifax in Nova Scotia. Beryl is moving NE, or 50 degrees, 3 knots. The estimated minimum central pressure is 1010 mb. The maximum sustained wind speeds are 35 knots with gusts to 45 knots. Little change in strength is forecast today. Beryl should begin to weaken by this evening when it moves over colder water. The cyclone is expected to degenerate into a remnant low pressure system late tonight or early Monday. A surface trough passes through 32N64W to 29N70W and 27N76W. Widely scattered moderate to isolated strong rainshowers are from 27N to 32N between 60W and 70W. Isolated moderate rainshowers are from 22N to 31N between 70W and 80W. Please read the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC and high seas forecasts issued by the National Weather Service under AWIPS header NFDHSFAT1 and WMO header FZNT01 for more information. Gale-force NE-to-E winds will be diminishing today in a few hours. The gale-force winds will return to the coastal waters of Colombia for Sunday night, Tuesday night, and Wednesday night. Expect the sea heights to range from 11 feet to 14 feet in the areas that are the closest to the gale-force winds during the next few days. Please read the High Seas Forecast, under the AWIPS/WMO headers HSFAT2/FZNT02 KNHC, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 27W/28W from 17N southward, moving W 10 to 15 knots. A 1012 mb low pressure center is along the southern part of the tropical wave near 08N. The wave is in a low to moderate deep layer wind shear environment and GOES-16 RGB's show massive Saharan dry air and dust continue to affect the wave. Any precipitation is near the ITCZ, from 06N to 10N between 24W and 36W. An Atlantic Ocean tropical wave is along 56W/59W from 19N southward, moving W 15 to 20 knots. The wave is in a low to moderate deep layer wind shear environment. It continues to be impacted by Saharan dry air and dust intrusion to its environment, which are hindering precipitation at this time. A Caribbean Sea tropical wave extends from Haiti to northern Colombia, moving W 10 to 15 knots. CIRA LPW shows abundant shallow moisture in the Caribbean Sea. Strong deep layer wind shear in this region is limiting convection to isolated showers from 75W eastward. A western Caribbean Sea tropical wave is along 81W from 17N southward, moving westward 15 knots. GOES-16 water vapor imagery at the lower levels shows that the wave is in a very dry environment. Scattered moderate to strong rainshowers cover the area that is from 09N to 12N between 81W and 86W, in the coastal waters and in parts of northern Costa Rica and southern Nicaragua. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the coastal sections of Guinea near 10N14W, to the 1012 mb low pressure center that is associated with the 27W/28W tropical wave, and to 06N34W. The ITCZ continues from 06N34W, to 05N40W, 06N50W, and to the coastal areas of French Guiana and Suriname near 05N55W. Precipitation: widely scattered moderate to isolated strong rainshowers from 04N to 08N between 08W and 16W, and from 06N to 10N between 24W and 36W. isolated moderate rainshowers are within 240 nm to the north of the ITCZ, within 180 nm to the south of the ITCZ between 40W and 50W, and within 120 nm to the north of the ITCZ between 50W and 58W. ...DISCUSSION... GULF OF MEXICO... A 1018 mb high pressure center is near 27N87W. The surface pressure gradient is flat and weak. High pressure will prevail across the northern waters through Thursday. A surface trough will move westward off the Yucatan Peninsula each evening through Thursday, enhancing nocturnal winds in the SW Gulf. CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details about the gale-force wind conditions along the coast of Colombia. Please read the TROPICAL WAVES section for details about the tropical waves that are moving through the Caribbean Sea. Gale-force NE-to-E winds will be present off the coast of Colombia: on Sunday night, on Tuesday night, and on Wednesday night. Nocturnal winds will pulse to near gale force each night elsewhere in the south central Caribbean Sea. NE swell will propagate into the tropical N Atlc forecast zones early next week, building seas to near 8 ft. Fresh to strong winds will prevail in the central Caribbean Sea through the middle of next week. ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details about Subtropical Storm Beryl. Broad surface anticyclonic wind flow covers the Atlantic Ocean from 20N northward between Africa and 66W. A 1031 mb high pressure center is near 36N42W. A surface trough passes through 32N64W to 29N70W and 27N76W. The trough is forecast to dissipate slowly through Sunday. High pressure will build in the wake of the trough and prevail through the middle of next week. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos