000 AXNT20 KNHC 251752 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 152 PM EDT Sun Aug 25 2019 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...SPECIAL FEATURES... The center of Tropical Storm DORIAN, at 25/1500 UTC, is near 11.2N 52.9W. DORIAN is moving W, or 280 degrees, 12 knots. The estimated minimum central pressure is 1008 mb. The maximum sustained wind speeds are 35 knots with gusts to 45 knots. Widely scattered to scattered moderate and isolated strong rainshowers are within 200 nm of the center in the NW semicircle. The Public Advisories about Tropical Storm DORIAN are issued under WMO header WTNT35 KNHC and under AWIPS header MIATCPAT5. The Forecast/Advisories about Tropical Storm DORIAN are issued under WMO header WTNT25 KNHC and under AWIPS header MIATCMAT5. A surface trough extends from 32N75W in the Atlantic Ocean, to a 1011 mb low pressure center that is near 31N77W. The trough continues to Florida, just to the E of Lake Okeechobee, and to 24N83W in the SE Gulf of Mexico. Scattered moderate to strong rainshowers are within 240 nm to the east of the trough from 25N northward, within 60 nm on either side of the trough from 24N to 26N in Florida and along the SW coast of Florida. Isolated moderate rainshowers are elsewhere from 24N northward from 86W eastward. Environmental conditions appear to be conducive for gradual development. It is likely that a tropical or subtropical depression may form within the next few days, while the system moves slowly northeastward well offshore of the southeastern United States. Interests along the coasts of South Carolina and North Carolina should continue to monitor the progress of this system. The Air Force Reserve Hurricane Hunter aircraft mission that was scheduled for this afternoon was canceled. Another aircraft is scheduled to investigate the system on Monday, if necessary. The chance of development into a tropical cyclone through 48 hours is high. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 31W, S of 21N, moving W 10 knots. Rainshowers are possible from 10N to 26N between Africa and 44W. A Caribbean Sea tropical wave is along 68W/69W, S of 20N, moving W 15 to 20 knots. Isolated moderate rainshowers are within 180 nm to the west of the wave, from 16N to central sections of Hispaniola. A Caribbean Sea tropical wave is along 84W/85W, S of 22N, moving W 10 to 15 knots. The wave extends from the NW tip of Cuba, through Honduras, Nicaragua, and Costa Rica. Isolated moderate rainshowers are from 17N northward from Jamaica westward. The GFS model for 250 mb, for 500 mb, and for 700 mb, shows an upper level inverted trough in the western Caribbean Sea near the wave. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Mauritania near 18N16W, to 16N23W near the Cabo Verde Islands, to 12N33W and 12N37W. The ITCZ continues from 12N37W to 12N47W. Widely scattered moderate to isolated strong rainshowers are from 04N to 15N from 20W eastward, from 06N to 10N between 27W and 40W, and from 09N to 11N between 40W and 45W. Isolated moderate rainshowers are elsewhere, from 12N southward, away from T.S. DORIAN, from 60W eastward. GULF OF MEXICO... Broad upper level anticyclonic wind flow spans the Gulf of Mexico. The GFS model for 500 mb and for 700 mb shows a trough in the NW corner of the Gulf of Mexico. Scattered to numerous strong rainshowers are from 27N northward from 91W westward, in the coastal waters of Louisiana and Texas. Widely scattered moderate to isolated strong rainshowers also are from 25N to 28N between 93W and 96W, about 180 nm off the coasts of Texas and NE Mexico. Relatively weak high pressure will remain in the area through Thursday night. The high pressure will maintain moderate to fresh south to southeast winds in the waters west of 90W. Winds will be mainly light to gentle east of 90W through the period. Upper level disturbances will keep unsettled weather conditions in much of the NW and north central Gulf of Mexico through Monday night. CARIBBEAN SEA... The GFS model for 250 mb, for 500 mb, and for 700 mb shows an upper level inverted trough, either in the NW corner of the Caribbean Sea or across the Yucatan Peninsula of Mexico. Isolated moderate rainshowers are in the NW part of the Caribbean Sea. The monsoon trough is along 09N between 74W in Colombia and 84W just off the coast of Costa Rica in the eastern Pacific Ocean. Scattered to numerous strong rainshowers are in the coastal plains, and within 90 nm of the coast from 08N to 13N between 80W and 85W, from Panama to Nicaragua. Warming cloud top temperatures, and weakening but possibly still lingering precipitation, are within 120 nm to the north of the monsoon trough between northern Colombia and 80W. Widely scattered moderate to isolated strong rainshowers are in northern Colombia from the monsoon trough to 10N. Fresh to strong trade winds in the south central Caribbean Sea will increase gradually in areal coverage through Monday. Fresh to strong east to southeast winds will pulse in the Gulf of Honduras at night from Monday through Wednesday. Tropical Storm Dorian near 11.2N 52.9W 1008 mb at 11 AM EDT moving W 12 kt. Maximum sustained winds 35 kt gusts 45 kt. Dorian will move to 11.5N 54.6W this evening and to 12.0N 56.9W Mon morning with maximum sustained winds 45 kt gusts 55 kt. Dorian will continue to strengthen gradually, as it moves to 12.7N 59.1W Mon evening, with maximum sustained winds 50 kt gusts 60 kt, then cross into the eastern Caribbean Sea near 13.5N 61.2W Tue morning with maximum sustained winds 55 kt gusts to 65 kt and reach hurricane strength near 15.6N 65.3W with maximum sustained winds 65 kt gusts 80 kt by early Wed, before it weakens to a tropical storm near 17.5N 69.0W early on Thu with maximum sustained winds 60 kt gusts 75 kt. ATLANTIC OCEAN... One upper level cyclonic circulation center is near 30N63W. A surface trough is along 31N56W 27N57W 25N59W. Widely scattered moderate to isolated strong rainshowers are within 180 nm to the east of the trough, and within 120 nm to the west of the trough. Other isolated moderate rainshowers are within 180 nm on either side of the line that runs from 32N50W 27N56W 23N66W. Low pressure near 31N77W 1011 mb will continue to track northeastward, to north of the area near 33N73W 1009 mb by early Monday. A trough will trail from the low, to near West Palm Beach. Unsettled weather, scattered to numerous rainshowers and thunderstorms, some with strong gusty winds and rough seas, is expected in the waters that are between 72W and 80W during the next couple of days. Environmental conditions appear conducive for gradual development of the low pressure system. A tropical or subtropical depression is likely to form within the next few days, as the low tracks to the NE north of the area. Gentle to moderate southeasterly winds will continue elsewhere across the area. Tropical Storm Dorian, currently in the tropical Atlantic Ocean, is forecast to move across the eastern Caribbean Sea as a hurricane by the middle of the week, and near the far southeastern waters as a tropical storm by late in the week. Expect increasing winds and building seas in those waters with the approach of Dorian. $$ MT