497 AXNT20 KNHC 200601 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu May 20 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0540 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Guinea near 11N15W, to 09N20W, 05N27W. The ITCZ continues from 05N27W, to 03N34W, to 02N40W. Precipitation: scattered moderate to widely scattered strong is within 390 nm to the south of the monsoon trough between 14W and 22W, and within 135 nm to the north of the ITCZ between 33W and 42W. Scattered moderate to strong is from 03N to 06N between 43W and the coast of Brazil and French Guiana. GULF OF MEXICO... One surface trough extends from the SW Louisiana to the coast of Mexico near Tampico. A second surface trough is in the Texas coastal waters. Precipitation: scattered moderate to widely scattered strong is covering the Gulf of Mexico from 91W westward. Precipitation: widely scattered moderate to isolated strong is from 25N southward from 89W eastward. An inland Mexico surface trough passes through the Isthmus of Tehuantepec to the western sections of the Yucatan Peninsula. Precipitation: scattered moderate to widely scattered strong covers the areas of northern Guatemala and the Yucatan Peninsula from 20N southward. An upper level trough passes through south Texas, into the SW corner of the Gulf of Mexico. The scatterometer winds show that fresh-to-strong SE winds are from 20N northward between 85W and 94W. The sea heights are ranging from 8 feet to 9 feet from 22N northward. The sea heights that are in the Straits of Florida, between 80W and 84W, are ranging from 8 feet to 10 feet. Strong to near severe thunderstorms are expected to continue across the NW and N central Gulf of Mexico, from tonight through Friday, and will be capable of producing gale-force wind gusts and sea heights in excess of 12 feet. Meanwhile, a strong ridge stretching from the eastern seaboard to the NE Gulf of Mexico, will continue to dominate the Gulf waters during the remainder of the week. The pressure gradient, between the ridge and deepening low pressure in the Southern Plains and northern Mexico, will result in fresh to strong SE winds and high seas across the Gulf region, from tonight through Saturday. The sea heights will peak from 10 feet to 13 feet on Thursday and Friday in the Straits of Florida, with 12 foot seas in the central Gulf on Friday. CARIBBEAN SEA... Precipitation: Isolated moderate rainshowers cover the areas that are from 17N northward. The monsoon trough passes through Colombia near 11N73W, through Colombia and Panama, beyond southern Costa Rica, and into the eastern Pacific Ocean. Precipitation: isolated to widely scattered moderate is inland, in parts of NW Venezuela, and elsewhere in Colombia. Upper level westerly wind flow spans the Caribbean Sea. The GFS model for 500 mb shows an anticyclonic circulation center is in eastern Honduras/NE Nicaragua. The GFS model for 700 mb shows an inverted trough that runs from Jamaica into the SW corner of the Caribbean Sea. A ridge is along 17N/18N from 69W eastward. Broken to overcast low level clouds, and isolated moderate rainshowers, cover the rest of the Caribbean Sea. The clouds and isolated moderate precipitation are moving with the surface-to-low level wind flow. The scatterometer winds show that moderate-to-fresh easterly winds, and sea heights of 3 feet to 4 feet, are in the SE corner of the Caribbean Sea. Fresh-to-strong easterly winds, and sea heights that range from 5 feet to 7 feet, cover the central sections of the Caribbean Sea. Fresh-to-strong, with some possible gale-force, E-to-SE winds, and sea heights that range from 5 feet to 6 feet, are within 180 nm to the north of Honduras from 84W westward. High pressure off the U.S.A. East Coast will continue to build in the western Atlantic Ocean. Expect fresh to strong winds tonight in the central Caribbean Sea through early next week. Fresh to strong winds will occur also in the lee of Cuba, on Friday and during the weekend. Expect fresh to strong easterly winds in the Gulf of Honduras, mainly at night, through Thursday night. ATLANTIC OCEAN A 1016 mb low pressure center is near 30N56W. A stationary front extends toward the southwest from the 1016 mb low pressure center, to 25N60W 23N70W, and to 23N76W in the Bahamas. A warm front extends to the northeast of the 1016 mb low pressure center, to 31N52W and 30N47W. The front is stationary from 30N47W beyond 31N41W. Strong to near-gale force winds are within 280 nm of the center in the NE semicircle. Sea heights of 9 feet are within 200 nm of the center in the NE quadrant. Fresh-to-strong NE-to-E winds, and sea heights ranging from 7 feet to 9 feet, cover the Atlantic Ocean, from the stationary front northward, from 70W westward. Precipitation: widely scattered moderate to isolated strong is within 300 nm to the E, the SE, and the S of the 1016 mb low pressure center and the stationary front that trails the low pressure center. Scattered to numerous strong is to the north of the warm front. Isolated moderate to locally strong is from Hispaniola and Cuba to 27N from 70W westward. The low pressure center is forecast to move westward and southwestward in warmer waters on Friday. It is likely to become a short-lived subtropical cyclone, late on Friday and into the weekend, near and to the northeast of Bermuda. The system is expected to move toward the north and northeast, into a more hostile environment, by late Sunday into Monday. A surface ridge passes through 31N34W, to 26N48W, to 17N64W in the NE corner of the Caribbean Sea. An upper level cyclonic circulation center is on top of northern half of The Western Sahara. Comparatively drier air in subsidence is apparent in water vapor imagery in the coastal waters of The Western Sahara and Morocco. N-to-NE fresh-to-strong winds are in the METEO-FRANCE forecast area, that is called AGADIR. The sea heights are ranging from 8 feet to 9 feet. The current stationary front extends across the western Atlantic Ocean, from 23.5N65W to the southeast Bahamas. This front will weaken through Thursday, as it moves southward and approaches the Windward Passage and Hispaniola. Meanwhile, the pressure gradient between high pressure off the eastern seaboard and the frontal boundary will support an area of fresh to strong easterly winds N of the front and W of 65W Wed through Fri. Seas will peak around 10 feet, to the E of the Bahamas, from tonight through early Thursday. $$ mt/SS