000 AXNT20 KNHC 210604 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Wed Jul 21 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 0550 UTC. ...SPECIAL FEATURES... Caribbean Sea Gale Warning: The surface pressure gradient, between the Atlantic Ocean ridge and the comparatively lower surface pressure in Colombia, will help to support gale-force winds off the coast of Colombia and in the Gulf of Venezuela, tonight, and again on Wednesday night. The sea heights are forecast to range from 10 feet to 14 feet. The comparatively fastest wind speeds will be in south central Caribbean Sea. Please, read the High Seas Forecast, issued by the National Hurricane Center, at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 28W/29W, from 21N southward, moving westward 10 to 15 knots. Precipitation: scattered moderate to widely scattered strong is from 07N to 11N between 28W and 33w, and from 11N to 12N between 26W and 27W. An Atlantic Ocean tropical wave is along 49W, from 20N southward, moving westward 10 to 15 knots. Precipitation: widely scattered moderate to isolated strong is from 10N to 13N within 180 nm to the east of the tropical wave. A tropical wave is along 89W/90W, from 19N southward, moving westward 10 to 15 knots. The tropical wave is moving through the Yucatan Peninsula, Guatemala, and El Salvador, into the eastern Pacific Ocean. Precipitation: scattered moderate to widely scattered strong is from 14N to 16N within 60 nm to 90 nm on either side of the tropical wave, in parts of Guatemala and Honduras, and in the southern sections of Belize. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border areas of Senegal and Guinea-Bissau, to 10N21W, 10N33W, and 08N47W. The ITCZ is along 07N/08N between 50W and 58W in the coastal waters of Guyana. Precipitation: scattered to numerous strong is within 150 nm to the south of the monsoon trough between 19W and 22W. Scattered moderate to widely scattered strong is from 07N to 11N between 28W and 33w, and from 11N to 12N between 26W and 27W. ...GULF OF MEXICO... An outflow boundary is about 240 nm to the SE of the Texas Gulf coast. The outflow boundary starts just off the coast of the Florida Panhandle, to 28N90W and to 28N95W. Precipitation: isolated moderate is within 90 nm on either side of the outflow boundary. An inland stationary front extends from the upper Texas Gulf coast, through central Texas, beyond the Texas Big Bend. Precipitation: isolated to widely scattered moderate and locally strong is in the Deep South of Texas, spreading into the northeasternmost sections of Mexico. A diurnal surface trough is in the western sections of the Yucatan Peninsula. Warming cloud top temperatures, dissipating but remnant rainshowers, and convective debris clouds are within 60 nm to 90 nm on either side of the surface trough. Broad surface anticyclonic wind flow spans the Gulf of Mexico. A surface ridge passes through the southern tip of Florida, toward the coast of Mexico near 21N97W. The surface pressure pattern is flat and weak. A surface ridge extends from the Bermuda High, westward along 26N, and toward the northeastern Gulf of Mexico. The ridge will continue to move southward through the forecast period. Expect tranquil conditions in the Gulf of Mexico for the remainder of the week. Moderate to fresh E to SE winds will pulse on Wednesday night, to the NW of the Yucatan Peninsula, through the end of the week. ...CARIBBEAN SEA... A tropical wave is along 89W/90W, from 19N southward, moving westward 10 to 15 knots. The tropical wave is moving through the Yucatan Peninsula, Guatemala, and El Salvador, into the eastern Pacific Ocean. Precipitation: scattered moderate to widely scattered strong is from 14N to 16N within 60 nm to 90 nm on either side of the tropical wave, in parts of Guatemala and Honduras, and in the southern sections of Belize. The monsoon trough is along 10N, from 74W in Colombia, southwestward to the northern coast of Panama along 80W, beyond southern Costa Rica, into the eastern Pacific Ocean. Precipitation: isolated moderate is within 120 nm on either side of the monsoon trough. The southwestern end of an upper level trough, from the Atlantic Ocean near 27N68W, is reaching Cuba and Jamaica, and the parts of Honduras and Nicaragua. Precipitation: broad upper level cyclonic wind flow, and isolated moderate, cover the Caribbean Sea from 14N northward from 70W westward. Expect E winds from 20 to 25 knots, and sea heights from 4 feet to 6 feet, in the Atlantic Ocean and in the Windward Passage, from 20N to 21N between 70W and 72W. The Bermuda High to the north of the area, combined with lower pressure in N Colombia, will support fresh to strong NE to E winds in the central Caribbean Sea through the end of the week. Expect an increase in areal coverage of strong wind speeds, reaching gale-force, near the coast of Colombia and in the Gulf of Venezuela, tonight and on Wednesday night. Fresh to strong winds will reach as far to the north as the Hispaniola adjacent waters. Fresh to strong E winds will occur in the afternoons and early evenings in the Windward Passage, through Friday. Fresh to strong winds are expected to pulse in the Gulf of Honduras on Wednesday night and on Thursday night. ...ATLANTIC OCEAN... An upper level trough extends from a 27N68W cyclonic circulation center, to the Bahamas, to Cuba, and to Jamaica, and to Honduras and Nicaragua. Broad upper level cyclonic wind flow covers the Atlantic Ocean within 240 nm on either side of the trough. Precipitation: isolated moderate to locally strong is in the area of the upper level cyclonic wind flow. Precipitation: isolated moderate to locally strong is to the northwest of the line that extends from Bermuda to the Straits of Florida. This precipitation is on the northern side of a 500 mb- to-700 mb ridge. A broad surface trough extends from central Georgia to SE Louisiana. A surface trough is along 49W/50W, from 26N to 31N. Precipitation: isolated moderate rainshowers are within 60 nm on either side of the trough. A 1026 mb high pressure center is near 32N51W. Broad surface anticyclonic wind flow covers the Atlantic Ocean from 20N northward, between Africa and 80W, away from the 49W/50W surface trough. Expect E winds from 20 to 25 knots, and sea heights from 4 feet to 6 feet, in the Atlantic Ocean and in the Windward Passage, from 20N to 21N between 70W and 72W. Fresh to strong E winds will pulse in the afternoons and evenings to the north of Hispaniola for the next several days. Moderate to fresh trade winds will prevail elsewhere to the south of 22N. Surface ridging associated with the Bermuda High will move slowly, southward to 27N by midweek, leading to quiescent conditions across the remainder of the western Atlantic Ocean. $$ mt/era