000 AXNT20 KNHC 062351 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 751 PM EDT Fri Sep 6 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... Hurricane Dorian is centered near 36.9N 72.7W at 06/2100 UTC or 290 nm SSW of Nantucket, Massachusetts and 600 miles SW of Halifax, Nova Scotia moving NE at 20 kt. The estimated central pressure is 958 mb and the maximum wind speed of 80 kt with gusts to 100 kt. Scattered moderate to isolated strong convection is within 60 nm of the center and scattered moderate convection is elsewhere in feeder bands from 33N-43N between 66W-75W. Dorian will continue moving generally NE with an additional increase in forward speed is expected through Sunday. On the forecast track, the center of Dorian should move to the southeast of extreme southeastern New England tonight and Saturday morning, and then across Nova Scotia late Saturday or Saturday night. Some strengthening is possible during the next 24 hours. After that time, Dorian is forecast to become a post-tropical cyclone with hurricane-force winds Saturday night or Sunday while it is near or over eastern Canada. 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 27.9N 39.6W at 06/2100 UTC or 880 nm SW of the Azores moving NW at 15 kt. The estimated minimum central pressure is 1003 mb and maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered moderate convection is well north of the center from 28N-32N between 36W-44W. A turn to the west-northwest with a slight decrease in forward speed are expected on Saturday. Gabrielle is forecast to gradually turn to the northwest and north on Sunday, then move at a faster pace to the northeast on Monday. By late Sunday or Monday, Gabrielle is anticipated to become a hurricane. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC or the website hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave near the Cape Verde Islands extends its axis along 27W S of 19N, moving W at 15 kt. A 1011 mb low is embedded on the wave axis near 14N27W. Scattered showers with isolated thunderstorms are noted from 15N-17N between 26W- 30W. Little, if any, development of this disturbance is expected for the next couple of days. Environmental conditions are likely to become more conducive for a tropical depression to form by Tuesday or Wednesday while the system moves westward across the tropical Atlantic Ocean. The chance of tropical cyclone formation during the next 48 hours is low. An Atlantic tropical wave that was once associated with Gabrielle is now along 44W S of 14N, moving W at 10-15 kt. Scattered showers and thunderstorms are seen from 07N-10N between 44W-46W. An eastern Caribbean tropical wave extends its axis along 64W S of 20N, moving W at 10-15 kt. Scattered showers are seen within 100 nm of the axis. A central Caribbean tropical wave extends its axis along 74W S of 18N, moving W at 15 kt. Scattered showers are over Hispaniola and in the north-central Caribbean. Enhanced convection is seen across northern Colombia. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 15N17W to the low pressure mentioned in the tropical waves discussion near 14N27W to 09N43W. The ITCZ is from 09N46W to 10N61W. Aside from the convection mentioned in the section above, numerous moderate to strong convection is moving off the coast of Africa from 08N- 13N and E of 16W. Scattered showers and thunderstorms are seen along the monsoon trough from 07N-12N between 30W-43W. Isolated thunderstorms are seen along the ITCZ from 08N-10N between 46W- 53W. GULF OF MEXICO... A cold front is dropping southward across the Gulf and Florida. This front enters the waters near 28N83W and stretches westward to New Orleans, Louisiana near 30N90W. High pressure is seen across the western portions of the Gulf anchored by a 1017 mb high near 29N95W. Two troughs are analyzed in the Bay of Campeche, the first begins near 18N94W to 22N92W, and the second is from 19N96W to 24N96W. Scattered moderate convection is seen across the Bay of Campeche from 19N-25N between 91W-97W. Latest scatterometer data shows light to gentle winds across the Gulf. A cold front over the northeast Gulf will shift southward and dissipate through early Sat. Weak high pressure will persist across the northwest Gulf through early next week, with gentle to moderate winds expected. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. Isolated thunderstorms are seen across the western Caribbean from 10N-19N and W of 79W. Isolated thunderstorms are also seen across the Greater Antilles with some of this activity reaching adjacent waters in the Caribbean. Otherwise, upper level ridging is keeping fair skies across most of the basin. Latest scatterometer data depicts gentle to moderate trades in the central Caribbean, with light to gentle trades elsewhere. Weak ridging will prevail north of the area through early next week. Moderate to fresh trade winds are expected through early next week, except increasing to moderate to fresh in the south central Caribbean Mon, then fresh to strong thereafter. 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 waters near 31N77W and stretches to the coast of Florida near 29N81W. Showers and thunderstorms are seen along this boundary, with some convection occurring from 27N-29N between 79W-80W. A weak 1017 mb high is near 28N66W. A trough extends into the central Atlantic from 26N63W to 31N58W. Showers are within 50 nm of the trough. Another trough is in the central Atlantic from 18N60W to 16N50W. This trough is producing scattered showers and thunderstorms from 16N-22N between 49W-59W. Scattered thunderstorms are also seen to the west of T.S. Gabrielle, from 26N-29N between 46W-49W. Large northerly swell from distant Dorian will dominate the waters mainly north of 28N into Sunday. A return to tranquil marine conditions is expected next week. $$ AKR