000 AXNT20 KNHC 191834 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Aug 19 2023 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 1200 UTC surface analysis and satellite imagery through 1750 UTC. ...SPECIAL FEATURES... Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on these special features. ...in the Eastern Tropical Atlantic Ocean (AL98): Shower and thunderstorm activity continues in association with a tropical wave, and a 1006 mb broad area of low pressure center, that is near 16N35W. This position is several hundred miles to the west of the Cabo Verde Islands. The environmental conditions appear to be generally favorable for more development of this system. It is likely for a short-lived tropical depression to form this weekend. It will move west-northwestward or northwestward 10 mph across the eastern tropical Atlantic Ocean. The upper level winds that will be over the system are forecast to increase by early next week. More development is not expected. The chance of formation into a tropical cyclone during the next 48 hours is high. Please, refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. ...to the East-Southeast of the Lesser Antilles (AL90): A 1007 mb low pressure center is near 12N59W. This low pressure center is along a tropical wave, that is just to the east of the Windward Islands. The precipitation pattern that is surrounding this weather feature has become comparatively better organized during the last 24 hours. More development of this system is likely. It is possible that a tropical depression may form early next week. It will be moving westward to west-northwestward 10 to 15 mph, across the Lesser Antilles and into the eastern and the central Caribbean Sea. Heavy rainfall is possible in parts of the Windward Islands during the next couple of days. Anyone who has interests in the eastern and the central Caribbean should monitor the progress of this system. The chance of formation into a tropical cyclone during the next 48 hours is medium. Please, refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. ...in the Central Tropical Atlantic Ocean (AL99): A 1007 mb low pressure center is near 16N49W, roughly halfway between the Cabo Verde Islands and the Lesser Antilles. This weather system is producing disorganized rainshowers and thunderstorms to the east of its center. The environmental conditions are only marginally conducive. It is possible that a short-lived tropical depression may form during the next day or two. The weather feature will be moving est-northwestward 10 to 15 mph, through the tropical Atlantic Ocean. More development is not anticipated, since the upper level winds are expected to become increasingly unfavorable. The chance of formation into a tropical cyclone during the next 48 hours is medium. Please, refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. ...TROPICAL WAVES... A Caribbean Sea tropical wave is along 80W/81W, from 28N southward, moving westward 10 knots to 15 knots. Precipitation: isolated moderate to locally strong is within 240 nm on either side of the tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border areas Senegal and Guinea-Bissau, to the 16N35W low pressure center, to the 16N49W low pressure center. The ITCZ is along 15N51W 12N57W. Precipitation: widely scattered moderate to isolated strong is from 05N to 16N from 30W eastward. ...GULF OF MEXICO... for the Western Gulf of Mexico: An area of disturbed weather, that is near the northwestern and central Bahamas now, is expected to move into the Gulf of Mexico by early next week. A broad area of low pressure is expected to form there. Some slow development of this system is possible. It is possible that a tropical depression may form. The weather system will westward, approaching the western Gulf of Mexico coastline by the middle of next week. Please, refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. A broad east-to-west oriented surface ridge is in the middle of the Gulf of Mexico. The weak surface pressure gradient is sustaining mainly light to gentle anticyclonic winds. The sea heights are reaching: 3 feet off the NW coast of the Yucatan Peninsula; 2 feet from the coastal waters of the middle Texas Gulf coast southward into the SW corner of the area, and in the SE Gulf/Straits of Florida; and 1 foot elsewhere. A surface ridge over the Gulf waters will support mostly gentle to moderate winds and slight seas across the basin through tonight. Looking ahead, an area of disturbed weather located near the northwestern and central Bahamas is expected to move into the Gulf of Mexico by early next week, where a broad area of low pressure is expected to form. Some slow development of this system is possible thereafter, and a tropical depression could form as it moves westward and approaches the western Gulf of Mexico coastline by the middle of next week. This system has a low chance of development in 48 hours and a medium chance in the next 7 days. ...CARIBBEAN SEA... Please, refer to the TROPICAL WAVES section, for details about the 80W/81W tropical wave. The pressure gradient between the ridge to the north of the islands and lower pressures in northern South America continue to support moderate to fresh easterly winds in the eastern and central Caribbean. Seas in these waters are 4-7 ft. Moderate or weaker winds, and seas of 2-5 ft, are elsewhere. The monsoon trough is along 08N/10N between 74W in Colombia, beyond Costa Rica, and into the Pacific Ocean. Precipitation: isolated moderate to locally strong is within 240 nm to the north and to the south of the monsoon trough. The 24-hour rainfall totals in inches, according to the Pan American Temperature and Precipitation Tables, MIATPTPAN, for the period that ended at 19/1200 UTC, are: 0.64 in Montego Bay in Jamaica; and 0.09 in Freeport in the Bahamas, and in Trinidad. Moderate to fresh trade winds will prevail over the eastern and central Caribbean through today. Winds will increase to fresh to strong over the eastern and central basin tonight through late Mon as a strong tropical wave moves across the region. Looking ahead, a low pressure, AL99, will move NE of Puerto Rico early next week, supporting moderate to fresh SE winds in the far E Caribbean Mon night through mid-week. Environmental conditions are forecast to become increasingly unfavorable for more development of this system during the next day or two while it moves west- northwestward 10 to 15 kt across the central tropical Atlantic. This system has a low chance of development in the next 7 days. ...ATLANTIC OCEAN... ...Near the coast of Africa: A tropical wave located near the western coast of Africa is producing a large area of disorganized showers and thunderstorms. Some slow development is possible while it moves generally west-northwestward across the tropical eastern Atlantic during the next several days. Please, refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. An expansive central Atlantic Ocean subtropical ridge covers the tropical Atlantic Ocean. The ridge is maintaining fairly dry weather conditions outside of the deep tropics. Fresh easterly trade winds are found south of 25N and west of 45W. The seas in these waters are 5-9 ft, with the highest seas occurring near 17N58W. Fresh to locally strong SE winds are south of 10N and west of 45W. Seas are 4-7 ft. Fresh to strong N-NE winds have been off Morocco and Western Sahara, with the comparatively fastest winds in the water passages of the Canary Islands. Meteo-France has been advising that gusts to near gale-force are going to be expected in those waters. Seas of 4-7 ft are north of 22N and east of 20W. Moderate or weaker winds, and slight to moderate seas, are elsewhere. Fresh to strong tradewinds will pulse off Hispaniola and the Windward Passage each evening into early next week. Fresh tradewinds south of 25N will persist through the weekend. A strong tropical wave will enhance winds and seas near the Leeward and Virgin Islands over the weekend, and north of Puerto Rico early next week. Environmental conditions are forecast to become increasingly unfavorable for further development of this system during the next day or two while it moves west-northwestward 10 to 15 kt across the central tropical Atlantic. This system has a low chance of development during the next 7 days. $$ mt/ar