000 AXNT20 KNHC 081804 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 204 PM 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Post-Tropical Cyclone Dorian is centered near 50.0N 59.4W at 08/1800 UTC or 40 nm E of Chevery Quebec and 145 nm NNE of Cape St. George Newfoundland moving NE at 23 kt. Estimated minimum central pressure is 965 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Numerous showers are moving across eastern Canada. Dorian will be moving near or over northwestern Newfoundland or eastern Labrador this afternoon and then enter the North Atlantic this evening. The post-tropical cyclone is forecast to drop below hurricane strength after passing Newfoundland later today, and it is forecast to be absorbed by another large low pressure system in a couple of days. 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 33.8N 49.0W at 08/1500 UTC or 1260 nm W of the Azores moving NNW 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 33N-36N between 47W-50W. A turn to the north is forecast later today, followed by a turn to the northeast on Monday with an increase in forward speed. Some strengthening is possible through Monday. Gabrielle is then expected to weaken starting Monday night as it begins a transition to become an extratropical low. 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 19N, moving W at around 10-15 kt. Scattered moderate convection is in the vicinity of the wave axis from 04N-13N between 12W-21W. An eastern Atlantic tropical wave extends its axis along 34W S of 20N, moving W at 10-15 kt. A 1011 mb surface low is embedded in the wave environment centered near 14N37W. Scattered showers are noted near the low from 12N-18N between 33W-40W. Some slow development of this system is possible during the next several days while the low moves westward across the 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 53W S of 15N, moving W at 10-15 kt. Scattered showers are noted from 07N-12N between 51W-55W. A west-central Caribbean tropical wave extends its axis along 74W S of 18N, moving W at 15-20 kt. Scattered showers are noted along the northern portion of the wave near Jamaica, and scattered moderate isolated strong convection south of 10N mostly near the the NW coast of Colombia and Panama. A west-central Caribbean tropical wave extends its axis along 81W S of 17N, 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 18N16W to the low pressure mentioned in the Tropical Waves section above near 14N37W to 09N44W. The ITCZ begins near 09N44W to 08N51W. Aside from the convection mentioned in the section above, scattered moderate convection is from 10N-12N between 41W-47W. GULF OF MEXICO... A surface trough stretches across the eastern Gulf from the west coast of Florida near 26N81W to 22N84W. A few showers are along the boundary. In the Bay of Campeche, another surface trough is analyzed from 23N90W to 17N93W. Scattered moderate showers and storms are noted near this trough from 20N-25N between 88W-95W. High pressure is building across the far western Gulf, anchored by a 1017 mb high centered near 26N92W. Weak high pressure will remain over the area through next week, with mainly gentle to moderate winds expected, except for occasionally fresh winds near the Yucatan Peninsula mainly in the evenings. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. An upper-level high is centered in the NW Caribbean and an upper low meanders into the eastern Caribbean Sea. This is causing scattered showers across the Greater Antilles. Scattered moderate convection is also noted in the SW basin from the monsoon trough, S of 10N between 75W-83W. Scattered moderate convection is also noted north of the Gulf of Honduras. 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 27N71W. A surface trough extends across the central Atlantic from 31N61W to 29N64W with scattered showers and thunderstorms occurring along and north of the trough, and another trough to the east from 31N58W to 28N60W. Scattered showers are present in the vicinity along 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. $$ MTorres