000 AXNT20 KNHC 202337 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 737 PM EDT Thu Aug 20 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Tropical Depression Thirteen is centered near 16.7N 53.9W at 20/2100 UTC or 535 nm E of the Northern Leeward Islands moving WNW at 18 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate to strong convection extends outward 180 nm in the western semicircle. Scattered moderate convection is elsewhere within 210 nm western semicircle and 150 nm SE quadrant. Seas are up to 10 ft near the center. On the forecast track, the depression is expected to move near or north of the northern Leeward Islands by late Friday and near or north of the Virgin Islands and Puerto Rico on Saturday. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details. Tropical Depression Fourteen is centered near 14.3N 81.0W at 20/2100 UTC or 135 nm ESE of Cabo Gracias a Dios on the Nicaragua and Honduras border, moving W at 16 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate to strong convection is noted within 300 nm in the northern semicircle and 210 nm southern semicircle, including over E Honduras, NE Nicaragua, Jamaica and the Cayman Islands. On the forecast track, the center of the system will move near or just north of the northeastern coast of Honduras and the Bay Islands on Friday and will approach the east coast of the Yucatan Peninsula of Mexico on Saturday. The center is then expected to cross the Yucatan Peninsula Saturday night and move into the south-central Gulf of Mexico on Sunday. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPATA.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. ...TROPICAL WAVES... A tropical wave near the western Africa coast is producing disorganized showers and thunderstorms within a few hundred nm of the coastline. This wave is expected to move over the far eastern tropical Atlantic on Fri, and some slow development is possible through the weekend while it moves west-northwest at 15 kt across the eastern tropical Atlantic. Scattered moderate isolated strong convection is noted from 11N-16N, east of 20W. Scattered moderate convection is also noted farther S along the wave axis from 04N- 10N. This system has a low chance of tropical cyclone formation during the next 48 hours, but a medium chance within 5 days. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. The tropical wave that was analyzed along 46W at 20/1200 UTC has been removed from the analysis. An eastern Caribbean tropical wave extends its axis along 65W from 20N southward, moving W at 15-20 kt. Scattered showers and isolated thunderstorms are noted in the Virgin Islands and also farther south along the wave axis between Trinidad and NE Venezuela. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal areas of Mauritania near 19N16W to 09N29W to 08N44W. The ITCZ extends from 12N55W to 09N61W. In addition to the convection associated with the systems described above in the Special Features and Tropical Waves sections, numerous moderate to scattered strong convection is noted south of the monsoon trough from 06N-10N between 21W-25W. Scattered moderate convection is from 06N-10N between 40W-46W. Scattered showers and isolated tstorms are with 90 nm of the ITCZ. GULF OF MEXICO... A weakening stationary front extends from a 1010 mb low pressure near New Orleans to Galveston, Texas. Ahead of it, a weak surface trough extends from 30N87W to 24N91W. Broad ascent over the northeast Gulf is leading to scattered moderate showers and isolated tstorms over the eastern Gulf east of 90W. Elsewhere, light to gentle winds and seas of less than 3 ft prevail. Tropical Depression Thirteen is forecast to pass near or just north of Puerto Rico on Saturday as a tropical storm. Thirteen could strengthen to a hurricane by the time it reaches the vicinity of South Florida or the Florida Straits on Monday. Thereafter, it could move through the eastern Gulf of Mexico, late Mon into late Tue, possibly at hurricane intensity. Tropical Depression Fourteen is forecast to be a tropical storm in the Gulf of Honduras early Saturday. It should then move NW across Yucatan and into the south-central Gulf of Mexico on Sunday. Fourteen could strengthen some as it continues NW to the NW Gulf of Mexico early next week. CARIBBEAN SEA... Widespread shower activity covering most of the western Caribbean is related to T.D. Fourteen. See above discussion in Special Features for T.D. Fourteen over the Caribbean. South of T.D. Fourteen, moderate to fresh winds are noted south of Hispaniola in the central Caribbean, while for portions of the eastern and western Caribbean sea away from T.D. Fourteen, gentle to moderate trades are occurring. Scattered showers and tstorms associated with the monsoon trough are within about 180 nm of the Panama coast. Seas near and east of T.D. Fourteen range from 6-10 ft, with 3-6 ft seas elsewhere in the basin. Tropical Depression Fourteen will strengthen and move into the south-central Gulf as a Tropical Storm. Fourteen will change little in intensity as it moves to near 25.0N 92.0W by early Mon. Expect tropical-storm-force winds and heavy rainfall over portions of Nicaragua, the Gulf of Honduras and the Yucatan Peninsula. Tropical Depression Thirteen is expected to strengthen to a tropical storm and begin impacting the northernmost Leeward and Virgin Islands Fri night and early Sat. The center is forecast to pass near, or north of Puerto Rico later during the day on Saturday. Expect a risk of squalls, strong winds and confused seas near the NE Caribbean passages near the northernmost Leeward and Virgin Islands, as well as the Mona Passage, as this tropical cyclone pass through, or possibly just to the north, of these areas. ATLANTIC OCEAN... See above discussion in Special Features regarding Tropical Depression Thirteen. Scattered moderate showers and isolated tstorms are in the waters east of Florida. This convection is related to the eastern Gulf of Mexico convection described above and from afternoon heating over Florida. Farther east, a weakening cold front is sagging south over the east-central Atlantic from 31N20W to 27N31W to 27N42W. No convection is occurring with this front. High pressure of 1021 mb centered near 30N52W continues to dominate much of the basin. Tropical Depression Thirteen is forecast to strengthen to a tropical storm on Friday. After passing near, or just north of Puerto Rico as a strengthening tropical storm on Saturday, Thirteen could bring storm surge, heavy rainfall and wind impacts over portions of Hispaniola, Cuba and the Bahamas. Thirteen could strengthen to a hurricane before it reaches the vicinity of South Florida or the Florida Straits on Monday. $$ Hagen