000 AXNT20 KNHC 042303 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Sep 5 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 2230 UTC. ...SPECIAL FEATURES... Major Hurricane Larry is centered near 17.4N 47.1W at 04/2100 UTC or 840 nm E of the Leeward Islands moving WNW at 12 kt. Estimated minimum central pressure is 958 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Numerous strong convection is noted within 200 nm of the center in the southern semicircle and numerous moderate convection within 215 nm in the northern semicircle. Seas are up to 42 ft with 12 ft seas extending within 300 nm in the northern semicircle and 240 nm in the southern semicircle. Larry is expected have a somewhat slower west- northwest to northwest motion is expected during the next few days. Some additional strengthening is forecast over the next day or so, followed by some intensity fluctuations. However, Larry is expected to remain at major hurricane strength through the early part of next week. Swells generated by Larry are expected to reach the Lesser Antilles on Sunday, and will continue to spread westward to portions of the Greater Antilles, the Bahamas, and Bermuda Monday and Tuesday. Significant swells will likely reach the eastern United States coastline after Labor Day. These swells are likely to cause life-threatening surf and rip current conditions. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave has an axis 17W from 19N southward, moving W at 10 to 15 kt. Scattered moderate convection is noted off the coast of Africa from 05N to 15N and E of 19W. An Atlantic Ocean tropical wave has an axis along 34W from 19N southward, moving westward at 10 to 15 kt. No significant convection is noted with this wave at this time. A central Caribbean Sea tropical wave has an axis along 73W from 20N southward, moving westward at 15 kt. Scattered moderate convection is noted across Hispaniola and the adjacent waters north of the island. Scattered showers are noted within 50 nm of the wave in the Caribbean. See the Eastern Pacific Tropical Weather Discussion for information on the tropical wave along 84W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 14N17W to 08N27W. The monsoon trough continues SW of Hurricane Larry near 11N47W to 09N51W. The ITCZ extends from 09N51W to the coast of Venezuela near 11N63W. Aside from the convection associated with Hurricane Larry and the tropical waves, isolated thunderstorms are noted along the ITCZ from 07N to 13N between 51W to 58W. GULF OF MEXICO... A stationary front extends from Tampa Bay, Florida near 28N83W to a 1012 mb low near 28N87W. A weakening stationary front extends west of the low to the southwest Louisiana coast near 30N93W. The significant convection associated with this front is over southern Florida. A trough extends across the Bay of Campeche from 22N96W to the coast of Mexico near 18N93W. Scattered moderate to strong convection is noted across the Bay of Campeche, S of 22N between 90W to 98W. A weak 1015 mb high is noted in the western Gulf near 27N93W. Light to gentle winds are noted across the Gulf of Mexico with moderate winds over the eastern Bay of Campeche. Seas are 1 to 3 ft across the basin. For the forecast, a surface trough currently over the Yucatan Peninsula will move into the southwest Gulf through early Sun, then move northward over the western and north-central Gulf of Mexico through the middle of next week. Unfavorable upper level winds should limit development through Mon, but environmental conditions may become somewhat favorable for gradual development through mid week. Elsewhere, a stationary front over the northeast Gulf will gradually dissipate through Sun, while weak high pressure dominates much of the remainder of the basin. CARIBBEAN SEA... See Tropical Waves section above for details on a tropical wave in the central Caribbean. Scattered moderate to isolated strong convection is noted across the Gulf of Honduras and the NW Caribbean from 16N to 22N and W of 81W. The monsoon trough extends across the SW Caribbean with showers and isolated thunderstorms along it, S of 11N between 76W to 83W. Moderate to fresh trade winds are noted in central and eastern Caribbean with seas 3 to 6 ft. Light to gentle tradewinds in the western Caribbean and moderate to locally fresh winds are noted in the Gulf of Honduras. Seas are 1 to 3 ft in this area. For the forecast, Major Hurricane Larry near 17.4N 47.1W 958 mb at 5 PM EDT moving WNW at 12 kt. Maximum sustained winds 110 kt gusts 135 kt. The closest point of approach of the center of Larry to the Leeward Islands is expected to be more than 500 nm by late Mon as Larry moves to near 23N55W. However, associated rough seas will move west of 55W tonight into early Sun, reaching the Leeward Islands and Atlantic entrances Mon, then subside through mid week as Larry moves farther north of the region. Elsewhere, gentle to moderate trade winds will persist, pulsing to fresh winds off Colombia mainly at night. ATLANTIC OCEAN... Please see the Special Features section for details on Major Hurricane Larry and the tropical waves section for more information on the two waves in the Atlantic. A 1012 mb low is noted NE of the northern Bahamas near 30N74W. A stationary front extends west of the low to south of Cape Canaveral, Florida near 28N81W. Scattered moderate to isolated strong convection is N of 23N between 64W to 80W, including thunderstorms impacting the northern Bahamas. Moderate NE winds are behind the front with gentle to moderate SW winds ahead of it. Seas are 3 to 6 ft. Meanwhile, an upper level low near 22N65W is leading to scattered moderate convection north of Puerto Rico from 22N to 27N between 59W to 67W. Winds in this area are gentle to moderate with seas to 5 ft. High pressure extends across the central and eastern Atlantic anchored by a 1018 mb high near 28N38W and near 30N51W. Gentle to moderate winds are noted with seas 3 to 6 ft. For the forecast W of 65W, Hurricane Larry near 17.4N 47.1W 958 mb at 5 PM EDT moving WNW at 12 kt. Maximum sustained winds 110 kt gusts 135 kt. Larry will move to 21.0N 52.3W Mon morning, 22.2N 54.0W Mon afternoon, 23.4N 55.6W Tue morning, and 24.7N 57.0W Tue afternoon. Larry will change little in intensity as it continues to move to the NW through mid week with area of tropical storm force winds expected to remain east of 65W at least into mid week. Rough seas in the form of large swell generated by Hurricane Larry are expected to propagate across the waters north of the Leeward Islands tonight and Sun, then spread west of 65W through the early part of the week. $$ AReinhart