000 AXNT20 KNHC 271756 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Fri Aug 27 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Ida has strengthened to a hurricane near 21.4N 82.4W as of 27/1710 UTC, or 25 nm ESE of the Isle of Youth moving NW at 13 kt. Estimated minimum central pressure is 987 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. The maximum sea heights are currently 18 ft. Numerous strong convection extends out 90 nm from the center in the N semicircle and 45 nm S semicircle. Scattered moderate to strong convection is elsewhere within 270 nm NE quadrant and 390 nm SE quadrant, including portions of Cuba and Jamaica. On the forecast track, the center of Ida will pass near or over the Isle of Youth and western Cuba later today, and move over the southeastern and central Gulf of Mexico tonight and Saturday. Ida is expected to strengthen to a major hurricane in the northern Gulf before making landfall along the U.S. northern Gulf Coast Sunday. A dangerous storm surge is forecast for portions of the Louisiana, Mississippi and Alabama coasts. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. Refer to the NHC High Seas Forecasts at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for marine impacts. Showers and thunderstorms associated with a 1008 mb low pressure near 13N 47.5W have become a little better organized today. Scattered moderate isolated strong convection is from 11N-15N between 44W-50W. The low is along a tropical wave with axis near 47/48W, from 04N-19N, moving W at 15 kt. Additional development of this system is expected, and a tropical depression is likely to form later tonight or Saturday before it moves into a less favorable environment. The disturbance is forecast to move west-northwestward today, then turn northward Saturday. This system has a high chance of tropical cyclone formation during the next 48 hours. Please refer to the NHC Tropical Weather Outlook at www.hurricanes.gov for more details. An elongated 1014 mb low pressure centered near 33N53W is along a surface trough extending from 35N50W to 29N60W. Disorganized scattered moderate convection prevails from 27N-34N between 50W-57W. Environmental conditions are expected to be marginally conducive for development. However, a tropical depression could still form over the weekend. The system is expected to drift eastward through Saturday, then accelerate northeastward Sunday toward the central north Atlantic. This system has a medium chance of tropical cyclone formation during the next 48 hours. Please refer to the NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 27W from 18N southward, moving W at 15 kt. Scattered moderate isolated strong convection is seen from 04N-12N between 24W-34W. A Caribbean Sea tropical wave is along 65W from 07N-20N, moving W at 15 kt. No significant convection is related to the wave at this time. The Caribbean Sea tropical wave that was along 83W at 0600 UTC has moved into Central America and has exited the basin. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Mauritania near 18N16W to 11N22W to 14N37W to 13N48W. The ITCZ continues from 10N51W to 09N60W. Aside from the convection discussed in the sections above, isolated moderate convection is noted from 12N-18N between 32W-41W. GULF OF MEXICO... A surface trough extends from 28N91W to the eastern Yucatan Peninsula. Scattered moderate isolated strong convection is noted over the north-central Gulf from 26N-31N between 87W-90.5W. Isolated moderate convection is also noted farther south along the trough from 23.5N-25.5N. A recent ASCAT pass shows fresh E to SE winds extending east of the trough to 85W, from 25.5N northward to 30.5N. Seas are 4 to 6 ft in this area. Another surface trough is along the coast of Texas. Scattered moderate convection is seen from 26N-30N between 93W-98W. The ASCAT data show gentle winds over the western Gulf of Mexico, where seas are 1 to 3 ft. Scattered moderate convection from Hurricane Ida and strong winds are over the Florida Straits. Strong numerous convection with Ida over western Cuba is about to emerge into the SE Gulf, and tropical storm force winds will reach the SE Gulf later this afternoon. Hurricane Ida will be located near or over western Cuba this evening, then strengthen to a major hurricane Sun morning over the north-central Gulf of Mexico near 27.5N 90W, then move inland as a major hurricane Sun evening near 29N91W. Ida will weaken to a tropical storm Mon morning inland near 30N91W, and then weaken to a tropical depression Tue morning inland near 33N90W. Maximum significant wave heights are forecast to reach 39 ft near the center of Ida in the north-central Gulf of Mexico Sun morning. For more details on Ida, please see the special features section above. CARIBBEAN SEA... Hurricane Ida is currently affecting portions of the NW Caribbean Sea. Please see the special features section above for details. The eastern Caribbean east of 74W is free of any significant shower activity. Fresh trades prevail over the central Caribbean, east of Jamaica. Gentle winds prevail in the SW Caribbean, south of 16N and west of 78W. Hurricane Ida will be located near western Cuba this evening, then move to near 24N86W Sat morning and to near 26N88W Sat evening. Tropical storm force winds will exit the NW Caribbean Sea by early Sat morning. Seas in the Yucatan Channel will diminish below 8 ft by Sat evening. Moderate to fresh winds are expected elsewhere through Tue, except for locally strong winds in the south-central Caribbean through the weekend. Otherwise, fresh to strong winds will pulse at night in the Gulf of Honduras Sun to Mon. ATLANTIC OCEAN... Refer to the section above for details on the Special Features developing across the basin and the tropical waves. An area of thunderstorms is occurring over Florida and the adjacent Atlantic waters, from the northwest Bahamas northward to 29N, between Florida and 77W. These thunderstorms, while not directly related to Ida, are being enhanced by upper-level anticyclonic outflow that is curving away from Ida. Farther south, scattered moderate convection over the Florida Straits is directly associated with Ida's outer rainbands. Strong winds prevail in the Florida Straits. A surface trough extends from 28N67W to 23N72W. Isolated moderate convection is near and just west of the trough. Moderate to fresh E to SE winds and seas of 4 to 6 ft prevail across much of the western Atlantic, west of 70W. A 1019 mb high pressure is near 26N60W. A ridge axis with gentle winds extends from this high to another 1021 mb high near 34N36W. Farther east, a surface trough extends from 31N26W to 28N31W to 24N33W, with only moderate NE winds observed west of the trough. A 1018 mb high is near 30N21W. ASCAT shows fresh NE to E trades from 13N-22N between 43W-60W, where seas are 6 to 9 ft, but 8 to 10 ft closer to the 1008 mb low near 13N 47.5W, mentioned above. For the forecast west of 65W, surface ridging will extend southward into the SW N Atlantic through Sun night supporting gentle to moderate E to SE winds. A weaker pressure gradient is expected early next week, which will result in light to gentle variable winds. Otherwise, fresh winds are expected to pulse N of Hispaniola during the evening hours through Sat night. $$ Hagen