000 AXNT20 KNHC 252232 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Aug 26 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 1800 UTC surface analysis and satellite imagery through 2200 UTC. ...SPECIAL FEATURES... A broad area of low pressure is expected to form over the southwestern Caribbean Sea during the next day or so from a tropical wave currently located north of Colombia. Environmental conditions are forecast to be conducive for development, and a tropical depression or tropical storm is likely to form late this week or over the weekend. The system is expected to move northwestward over the northwestern Caribbean Sea and near or across the Yucatan Peninsula of Mexico on Friday and into the Gulf of Mexico this weekend where conditions are expected to be favorable for additional development. Regardless of development, heavy rainfall and flooding will be possible through the weekend in portions of Nicaragua, Honduras, Guatemala, Belize, and the Yucatan Peninsula. This system has a medium chance of development within the next 48 hours. Refer to the National Hurricane Center Tropical Weather Outlook at www.hurricanes.gov and the High Seas Forecast at www.hurricanes.gov/marine for more details. A broad trough of low pressure is producing disorganized showers and thunderstorms over the central tropical Atlantic about 700 miles southeast of Bermuda. Only slow development of this system is expected during the next day or so due to unfavorable upper-level winds. Afterwards, environmental conditions are forecast to become more conducive for development, and a tropical depression is likely to form late this week or this weekend while the system turns eastward over the open central Atlantic. This system has a medium chance of development within the next 48 hours. Refer to the National Hurricane Center Tropical Weather Outlook at www.hurricanes.gov and the High Seas Forecast at www.hurricanes.gov/marine for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 35/36W, south of 19N, moving W at 10 to 15 kt. A 1008 mb low pressure is along the wave axis near 11.5N35.5W. Scattered moderate to isolate strong convection is noted from 10N to 16N and between 31W and 40W. Please see special features section for more on this disturbance. The axis of a tropical wave is near 55W, south of 19N, moving W at 10 to 15 kt. There is no significant deep convection associated to this wave. The axis of a tropical wave is near 77/78W, south of 20N, moving W at 10 to 15 kt. A 1006 mb low pressure is along the wave axis near 13N77.5W. Numerous moderate and scattered strong convection associated to this disturbance is covering much of the central Caribbean between 70W and 80W, including portions of Hispaniola, E Cuba, and Jamaica. Please see special features section above for more on this disturbance. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through Senegal near 15N17W and continues to low pres near 11.5N35.5W to 05N45W. The ITCZ continues from 05N45W to 07N54W. Aside from convection noted in the tropical waves section, scattered moderate isolated strong convection is observed from 04N to 17N E of 19W to the coast of Africa. This is ahead of the next tropical wave which will move into the eastern Atlantic late tonight. Scattered moderate convection is within 30 nm of the monsoon trough between 40W and 42W. ...GULF OF MEXICO... A surface trough extends from SE Louisiana to near 26N94W. Scattered moderate and isolated strong convection is noted within 180 nm east of the trough. Another surface trough is over the SW Gulf from 22N96W to 18N94W. Scattered moderate and isolated strong convection is west of the trough axis. Gentle to moderate winds are over the far SE Gulf, with light to gentle winds elsewhere. Seas are in the 3-4 ft range over the SE Gulf as well as in the Bay of Campeche. Elsewhere, seas are in the 1-3 ft range. For the forecast, a surface trough will move into the eastern Gulf tonight into Thu morning, bringing fresh NE to E winds. Otherwise, high pressure pressure will dominate the basin through Fri, producing mainly gentle to moderate E to SE winds. Fresh winds will pulse west of the Yucatan Peninsula tonight and again Thu night. A broad area of low pressure is expected to form over the southwestern Caribbean Sea during the next day or so. Environmental conditions are forecast to be conducive for development, and a tropical depression or tropical storm is likely to form late this week or over the weekend. The system is expected to move northwestward over the northwestern Caribbean Sea and near or across the Yucatan Peninsula of Mexico Fri night, and into the Gulf of Mexico this weekend, where conditions are expected to be favorable for additional development. Mariners should closely monitor the progress of this system. While not explicitly in the forecast, this system has potential for significant strengthening in the Gulf of Mexico. Expect a large increase in winds and seas this weekend in association with this system. ...CARIBBEAN SEA... Please see special features above for more on low pressure along an active tropical wave with a chance for tropical cyclogenesis. Fresh to strong winds prevail over the central Caribbean associated to the tropical wave and low. Moderate to fresh winds are over the eastern Caribbean and gentle to moderate winds are over the western Caribbean. For the forecast, fresh to locally strong trade winds will dominate most of the central Caribbean tonight. A broad area of low pressure is expected to form over the southwestern Caribbean Sea during the next day or so from a tropical wave currently located north of Colombia along 76W. Environmental conditions are forecast to be conducive for development, and a tropical depression or tropical storm is likely to form late this week or over the weekend. The system is expected to move northwestward over the northwestern Caribbean Sea and near or across the Yucatan Peninsula of Mexico Fri night, and into the Gulf of Mexico this weekend. Based on the forecast, winds and waves will likely increase Thu night through Sat over the northwest Caribbean, north of 15N and west of 78W. ...ATLANTIC OCEAN... Please see special features section above for more on a broad trough of low pressure over the central tropical Atlantic, which has the potential for tropical cyclone development. Elsewhere, a surface trough extends from 28N73W SW to Cuba. Scattered moderate and isolated strong convection is within 90 nm west of the trough. Fresh to strong winds are west of the surface trough. Fresh to strong winds are in the vicinity of the trough discussed in the special features section above. Elsewhere, moderate to fresh winds prevail. Seas are in the 8-12 ft range in the vicinity of the trough over the central tropical Atlantic, with seas in the 6-8 ft range NE of the Bahamas and also in the vicinity of the low near 11.5N35.5W. Elsewhere seas in the 4-6 ft range prevail. For the forecast W of 65W, a surface trough located over the central and northwest Bahamas will move into the eastern Gulf of Mexico by Thu morning. Fresh to strong NE winds are expected west of the trough axis, including the Florida Straits, through tonight. Otherwise, high pressure located just N of the forecast region will dominate the SW N Atlantic through Mon. Fresh to locally strong winds are expected to pulse N of Hispaniola during the evening hours through Sat night. $$ AL