000 AXNT20 KNHC 041920 TWDAT 000 AXNT20 KNHC 041745 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Oct 4 2020 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 1715 UTC. ...SPECIAL FEATURES... Tropical Storm Gamma is centered off the north coast of Yucatan near 22.2N 88.2W at 04/1500 UTC or 100 nm ENE of Progreso Mexico moving N at 2 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Numerous strong convection is within 90 nm of the center. Scattered moderate to strong convection is elsewhere over the SE Gulf of Mexico, S Florida, W Cuba, the Yucatan Channel, and the N Yucatan Peninsula, from 21N-28N between 81W-91W. Seas are building as Gamma moves farther offshore. A long fetch of persistent NE winds to the north of Gamma is support seas to 16 ft in the south- central Gulf. Gamma should turn toward the west or west-southwest tonight or Monday, and a slow southwestward motion should continue Monday night through early Wednesday. On the forecast track, the center of Gamma will meander offshore of the northern Yucatan Peninsula and over the extreme southern Gulf of Mexico today, and pass near or just offshore of the northern coast of the Yucatan Peninsula on Monday and Tuesday. Little change in strength is expected through this evening. Gradual weakening is anticipated to begin later tonight or on Monday and continue into Tuesday. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details. A tropical wave with an axis along 76W S of 20N is moving W at 10 kt producing scattered moderate to strong convection from 11N-17N between 71W-80W. Environmental conditions are expected to be conducive for additional development, and a tropical depression is likely to form within the next day or two. The system should move west-northwestward at 10 to 15 kt across the central and western Caribbean Sea today through Tuesday, and then move into the southern or southeastern Gulf of Mexico on Tuesday night and Wednesday. Locally heavy rainfall and gusty winds will be possible across portions of Hispaniola, Jamaica, Cuba, and the Cayman Islands during the next few days, and interests on those islands should monitor the progress of this disturbance. This system has a high chance of development within the next 48 hours. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 45W from 20N southward, moving W at 05-10 kt. A 1010 mb low is along the wave near 13N45W. Isolated moderate convection within 240 nm of the wave axis. This system has not become any better organized, and any development during the next day or so should be slow to occur while it moves west-northwestward or northwestward. Significant development is not expected beyond that time due to the system moving into a region of strong upper-level winds. This system has a low chance of development over the next 48 hours. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal sections of Senegal near 14N17W to 08N22W to 05N38W. The ITCZ continues from 05N38W to 09N44W and from 09N47W to the coast of French Guiana near 05N52W. Scattered moderate convection is from 02N-11N between 10W-25W. Isolated moderate convection is from 02N-08N between 25W-40W. GULF OF MEXICO... Please see the Special Features section above for information on T.S. Gamma. As of 04/1500 UTC, the tail-end of a stationary front is over central Florida from Daytona Beach Florida to S of Orlando Florida. Scattered moderate convection is within 60 nm of the front. Moderate to strong N to NW winds span across the eastern and central Gulf, including the eastern half of the Bay of Campeche. Gentle easterly winds are off the coasts of Texas through Alabama. Seas are from 3-5 ft across the northern and western Gulf with 9-16 ft across the south-central Gulf near T.S. Gamma. Low pressure along a central Caribbean tropical wave is expected to move from the northern Caribbean across western Cuba into the southeast Gulf Tue, possibly as a tropical depression or tropical storm. A cold front will move into the northern Gulf Mon, then stall and dissipate over the central Gulf through mid week as the low pressure moves northward. CARIBBEAN SEA... Please see the Special Features section on information regarding T.S. Gamma, and the tropical wave in the central Caribbean. The monsoon trough extends across the southwest Caribbean from 12N78W to the coast of Costa Rica near 10N83W. Scattered showers are within 90 nm of the axis. Scattered moderate convection is over the Virgin Islands and N of Puerto Rico from 18N-20N between 63W-67W. Gentle to moderate trade winds prevail across most of the Caribbean with fresh winds near the Greater Antilles and light winds in the SW Caribbean. Seas are from 3-6 ft across most of the basin with upwards of 8 ft near the low along the tropical wave, and 5 to 7 ft near the Yucatan Channel The focus turns to the development and track of the tropical wave south of Haiti. There is a high chance that a tropical depression or tropical storm may form by late Mon or early Tue as the low moves west-northwest through the northwest Caribbean, and to the south of Cuba. ATLANTIC OCEAN... The tail-end of a stationary front over the W Atlantic extends from 31N80W to Daytona Beach Florida. Scattered showers are within 60 nm of the front. The tail-end of a dissipating stationary front is further E from 31N78W to 29N79W. Scattered showers are within 45 nm of the front. A surface trough is over the central Atlantic from 31N49W to 24N51W. Isolated moderate convection is within 120 nm of the trough. A broad surface ridge extends from 1031 mb high near 39N37W west of the Azores to just east of the fronts. The gradient on the southwest side of this ridge is supporting fresh to strong E winds off the north coast of Hispaniola. There may be one more round of fresh to strong winds off Hispaniola tonight. Winds and seas will diminish thereafter as the ridge shifts east ahead of a third weak front that will move over the Atlantic waters east of NE Florida by early Mon, drift south through Tue then stall from 31N73W to near W Palm Beach Florida by mid week. In the eastern Atlantic, fresh to strong NE winds and seas to 9 ft are active off the African coast of Western Sahara and Mauritania. Elsewhere, generally moderate trade winds persist across the Atlantic with mostly 5 to 7 ft seas. $$ Formosa