000 AXNT20 KNHC 081030 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 630 AM EDT Sun Sep 8 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 0600 UTC surface analysis and satellite imagery through 1015 UTC. ...SPECIAL FEATURES... Post-Tropical Cyclone Dorian is centered near 48.5N 61.1W at 08/0900 UTC or 70 nm W of Cape St George Newfoundland moving NNE at 23 kt. Estimated minimum central pressure is 960 mb. Maximum sustained wind speed is 70 kt with gusts to 85 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 this track, Dorian will be moving near or over western Newfoundland later today and then enter the North Atlantic this evening. 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 32.7N 48.6W at 08/0900 UTC or 1100 nm W of the Azores moving NW at 11 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Scattered moderate convection is north and west of the center, from 27N-36N between 46W-54W. The storm is forecast to turn northward over the central Atlantic later today 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 17W S of 20N, moving W at around 10-15 kt. Scattered moderate convection is in the vicinity of the wave axis from 08N-17N between 10W-20W. An eastern Atlantic tropical wave extends its axis along 35W S of 20N, moving W at 10-15 kt. A 1011 mb surface low is embedded in the wave environment centered near 15N35W. Scattered showers are noted near the low from 14N-18N between 35W-39W. 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 54W S of 15N, moving W at 10-15 kt. Scattered showers are noted within 100 nm on either side of the wave axis. A west-central Caribbean tropical wave extends its axis along 74W S of 20N, moving W at 15-20 kt. Scattered showers are noted along the northern portion of the wave, mostly impacting Hispaniola and adjacent waters. A west-central Caribbean tropical wave extends its axis along 81W S of 18N, moving W at 10 kt. Scattered showers are noted along the southern portion of the wave, mostly impacting Central America and the EPAC waters. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 16N17W to the low pressure mentioned in the Tropical Waves section above near 15N35W to 09N42W. The ITCZ begins near 09N42W to 08N53W. Aside from the convection mentioned in the section above, scattered moderate convection is noted within 75 nm on either side of the ITCZ. GULF OF MEXICO... A surface trough stretches across the eastern Gulf from the west coast of Florida near 25N84W to 24N90W. A few showers are along the boundary. In the Bay of Campeche, another surface trough is analyzed from 22N90W to 19N93W. Scattered moderate convection and locally fresh winds are noted near this trough. High pressure is building across the far western Gulf, anchored by a 1017 mb high centered near 27N92W and a 1016 mb high centered near 28N87W. Latest scatterometer data depicts light to gentle winds across the basin. The frontal trough across the eastern 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 showers to move across the Lesser Antilles. Scattered moderate convection is also noted in the SW basin from the monsoon trough, S of 10N between 73W-82W. Scattered moderate convection is 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 high pressure ridging north of the area will be be replaced by stronger high pressure that builds southward over the western Atlantic and the U.S. eastern seaboard during the early part of the upcoming week. An induced tighter gradient between the high pressure and couple of tropical waves presently moving through the central and western Caribbean will allow for trades to increase in the south-central Caribbean beginning Mon, then diminish late in the week. Elsewhere, mainly moderate trade winds will continue through late in the week. ATLANTIC OCEAN... Refer to the sections above for details on Dorian, Gabrielle and three tropical waves moving across the basin. A 1017 mb surface high is near 28N68W. A surface trough extends across the central Atlantic from 19N56W to 15N64W with scattered showers and thunderstorms occurring along and north of the trough. Surface ridging prevails across the eastern Atlantic. A well defined low-level trough will move from E to W across the area during the upcoming week accompanied by scattered to numerous showers and thunderstorms. Otherwise, relatively weak high pressure across the area will gradually lift northward through through Thu. $$ ERA