000 AXNT20 KNHC 080001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 801 PM EDT Sat Sep 7 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 1800 UTC surface analysis and satellite imagery through 2320 UTC. ...SPECIAL FEATURES... Dorian, centered near 43.9N 63.9W at 07/2100, UTC has transitioned into a hurricane-force post-tropical cyclone. It is located about 40 nm SSW of Halifax, Nova Scotia and 150 nm ESE of Eastport, Maine moving NE at 25 kt. The estimated minimum central pressure is 953 mb. The maximum sustained wind speed is 85 kt with gusts to 105 kt. Numerous showers are moving across eastern Canada. Dorian will continue moving generally NE for the next 24 hours. After that, a turn toward the east- northeast is expected. On the forecast track, the center of Dorian should cross the coast of Nova Scotia near Halifax during the next few hours, then move across eastern Nova Scotia into the Gulf of St. Lawrence near Prince Edward Island tonight. The center should then pass near or over northern Newfoundland and eastern Labrador late tonight or Sunday morning. The post-tropical cyclone is expected to weaken during the next couple of days, and it is forecast to drop below hurricane strength by Sunday morning. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC or the website hurricanes.gov for more details. Tropical Storm Gabrielle is centered near 31.9N 46.5W at 07/2100 UTC or 1000 nm WSW of the Azores and moving WNW at 15 kt. The estimated minimum central pressure is 1002 mb and maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate convection is north and west of the center, from 27N-36N between 46W-54W. The storm is forecast to recurve over the central Atlantic during the next day or two and then accelerate northeastward into the north Atlantic Monday and Tuesday. Some strengthening is forecast during the next couple of days. Gabrielle is forecast to become an extratropical low and begin weakening on Tuesday. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC or the website hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave near the coast of Africa is along 15W S of 20N, moving W around 10-15 kt. Scattered moderate to strong convection is in the vicinity of the wave axis from 08N-17N between 10W- 16W. An eastern Atlantic tropical wave extends its axis along 31W S of 20N, moving W at 10-15 kt. A 1011 mb surface low is embedded in the wave environment centered near 14N31W. Scattered showers and isolated thunderstorms are noted north and west of the low from 14N- 18N between 27W- 36W. Gradual development of this system is possible, and a tropical depression could form by the middle of next week while the system moves westward across the eastern and central tropical Atlantic Ocean. The chance of tropical cyclone formation during the next 48 hours with this system is low. An Atlantic tropical wave extends its axis along 51W S of 15N, moving W at 15 kt. Scattered showers and isolated thunderstorms are noted within 100 nm on either side of the wave axis. A central Caribbean tropical wave extends its axis along 69W S of 19N, moving W at 15-20 kt. Scattered showers and thunderstorms are noted along the northern portion of the wave, mostly impacting the Dominican Republic. A west-central Caribbean tropical wave extends its axis along 77W S of 18N, moving W at 5-10 kt. Scattered showers and thunderstorms are noted along the northern portion of the wave, mostly impacting Jamaica. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal/The Gambia near 13N17W to the low pressure mentioned in the Tropical Waves section above near 14N31W to 09N49W. The ITCZ begins near 08N52W and extends to the coast of Venezuela near 09N61W. Aside from the convection mentioned in the section above, scattered moderate convection is noted along the monsoon trough from 06N-14N between 18W-47W. Showers and isolated thunderstorms are also moving across the ITCZ from 07N-09N between 52W-55W. GULF OF MEXICO... A trough stretches across the eastern Gulf from the west coast of Florida near 26N82W to 26N89W. A few showers are along the vicinity of the boundary. In the Bay of Campeche, a trough is analyzed from 18N92W to 24N91W. Scattered moderate to isolated strong convection can be seen from 22N-26N between 92W-96W. Some thunderstorms are occurring along the Yucatan and reaching adjacent waters, mostly E of 93W. High pressure is building across the far western Gulf, anchored by a 1017 mb high centered near 29N94W. Latest scatterometer data depicts light winds across the basin. A frontal trough extending from near Naples, Florida to the central Gulf will dissipate through tonight. Weak high pressure will persist across the Gulf through next week, with mainly gentle to moderate winds expected, except occasionally fresh near the Yucatan Peninsula. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. An upper level low is meandering into the eastern Caribbean. This is causing scattered thunderstorms to move across the Lesser Antilles through Puerto Rico. Numerous strong convection is occurring over Haiti and moving westward into the Caribbean, fro 17N-20N between 71W-75W. Scattered moderate convection is also seen in the SW basin from the monsoon trough, S of 11N between 73W-82W. Some isolated thunderstorms are also noted in the Gulf of Honduras. Latest scatterometer data depicts moderate trades in the central and southeast Caribbean, with light to gentle trades elsewhere. Weak ridging will prevail north of the area through next week. Winds in the south central Caribbean will increase slightly Monday through Thursday. Elsewhere, mainly moderate trade winds will prevail. ATLANTIC OCEAN... Refer to the sections above for details on Dorian, Gabrielle and two tropical waves moving across the basin. A cold front enters the Atlantic waters near 31N65W and stretches westward to 29N71W. Scattered showers are noted along this boundary. A 1017 mb surface high is near 26N71W. A surface trough extends into the central Atlantic from 31N56W to 26N63W with scattered showers and thunderstorms occurring along the trough from 26N-30N between 57W-62W. Another trough is in the central Atlantic from 16N55W to 24N64W with a 1013 mb low near 20N61W along the trough. It is about 179 nm from the northern portions of the Lesser Antilles. This trough is producing scattered moderate convection 18N-24N between 51W-62W. Surface ridging prevails across the eastern Atlantic. A well defined trough will move from SE to NW across the basin by the end of next week. Otherwise, broad high pressure and more tranquil marine conditions will prevail through the upcoming week. $$ AKR