770 AXNT20 KNHC 070525 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 125 AM 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... Hurricane Dorian is centered near 38.3N 70.2W at 07/0300 UTC or 170 nm S of Nantucket Massachusetts moving NE at 22 kt. Estimated minimum central pressure is 960 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Scattered moderate to strong convection is within 60 nm of the center and scattered moderate convection is elsewhere in feeder bands north of 37N between 65W-74W. 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 pass to the southeast of extreme southeastern New England Saturday morning, and then across Nova Scotia late Saturday. This system 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 29.3N 40.9W at 07/0300 UTC or 870 nm WSW of the Azores moving NW at 16 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Scattered moderate convection is well northwest of the center from 29N-33N between 39W-47W. A turn to the west-northwest is expected on Saturday. Gabrielle is forecast to gradually turn to the north on Sunday, then move at a faster pace to the northeast on Monday. 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 29W and south of 19N, moving W at 15 kt. A 1011 mb surface low is embedded on the wave centered near 14N29W. Scattered showers are noted from 15N-17N between 28W-31W. 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. The chance of tropical cyclone formation during the next 48 hours with this system is low. An Atlantic tropical wave extends its axis along is now along 46W from 05N-13N, moving W at 15 kt. Scattered showers are noted from 07N-10N between 45W-48W. An eastern Caribbean tropical wave extends its axis along 64W and south of 20N, moving W at 10-15 kt. Scattered showers are noted within 100 nm across the northern portion of the wave. A central Caribbean tropical wave extends its axis along 74W S of 18N, moving W at 5-10 kt. Scattered showers are over Hispaniola and in the north-central Caribbean in the wave's environment. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 15N17W to the low pressure mentioned in the Tropical Waves section above near 14N29W to 09N44W. The ITCZ is from 09N47W to 09N60W. Aside from the convection mentioned in the section above, scattered moderate convection is moving off the coast of Africa along and south of the monsoon trough mainly east of 17W. GULF OF MEXICO... A cold front is dropping southward across the eastern half of the Gulf reaching the Florida Peninsula. This front enters the waters near 27N83W to 27N86W to 29N90W. High pressure is building across the far west Gulf, centered near 29N94W. To the southwest, a thermal trough is developing over the Yucatan Peninsula and moving west across the Bay of Campeche enhancing winds and convection. Latest scatterometer data depicts light to gentle winds across the basin. The 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 across the area. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. Scattered moderate convection is noted over the southwest Caribbean due to the EPAC's monsoon trough proximity. This activity is south of 12N between 79W-82W. 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 west Atlantic waters near 31N78W and stretches to the coast of Florida near 29N81W. Scattered showers are noted along this boundary. To the east, a 1017 mb high is near 27N68W. A surface trough extends into the central Atlantic from 31N58W to 27N62W with scattered showers. Another trough is in the central Atlantic from 18N59W to 17N50W. This trough is producing scattered showers and thunderstorms from 16N-22N between 49W-59W. 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. $$ ERA