000 AXNT20 KNHC 061000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Sep 6 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Hurricane Larry is centered near 21.6N 52.4W at 06/0900 UTC, moving NW at 10 kt. Estimated minimum central pressure is 956 mb. Maximum sustained wind speed is 105 kt with gusts to 130 kt. The eye diameter is 50 nm on IR satellite imagery. Numerous moderate to strong convection is within 180 nm of the center. Seas of 12 ft or higher extend outward 300 nm from the center in the N semicircle, 240 nm SE quadrant, and 270 nm SW quadrant, with seas peaking at 45 ft. On the forecast track, a northwest motion with a slight decrease in forward speed is expected during the next few days. Little change in strength is forecast during the next day or so, followed by very gradual weakening. Swells generated by Larry are reaching the Lesser Antilles and are expected to spread westward to portions of the Greater Antilles, the Bahamas, and Bermuda later today and Tuesday. Significant swells should reach the east coast of the United States and Atlantic Canada by midweek. These swells are likely to cause life-threatening surf and rip currents. 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... An eastern Atlantic Ocean tropical wave has an axis along 26W, from 19N southward, moving W around 15 kt. Scattered moderate convection is noted from 06N to 09N between 20W and 30W. A central Atlantic Ocean tropical wave has an axis along 42W, from 17N southward, moving W around 10 kt. The wave is situated at the leading edge of a Saharan dust plume, so no significant convection is associated with this wave. A Caribbean Sea tropical wave has an axis along 80W, from Jamaica to central Panama, moving W at 10 kt. Scattered moderate convection is within 150 nm either side of the wave axis, mainly S of 14N. ...MONSOON TROUGH/ITCZ... The monsoon trough extends into the Atlantic Ocean off the coast of northern Senegal near 16N17W to 06N32W. The ITCZ extends from 06N32W to 05N39W, then continues W of a tropical wave from 04N42W to 06N52W to 09N61W. Aside from the convection mentioned in the Tropical Waves section above, scattered moderate convection is noted from 03N to 06N between 30W and 35W and from 04N to 08N between 46W and 51W. GULF OF MEXICO... A weak 1011 mb low along a surface trough is analyzed just off the west coast of the Yucatan Peninsula near 21N91W. The surface trough extends NNE from the low to near 24N89W. Locally fresh SE winds are occurring on the NE side of the low, just N of the Yucatan Peninsula. Scattered moderate convection is noted over the peninsula, extending northward to 25N. Numerous moderate to isolated strong convection is occurring within 90 nm offshore of Veracruz, Mexico. Generally modest surface ridging dominates the rest of the basin, with a surface high pressure of 1016 mb centered over the Florida Straits. This is leading to light to gentle winds and seas of 3 ft or less. For the forecast, the low pressure off the coast of the Yucatan Peninsula is forecast to move N or NE over the central and NE Gulf of Mexico over next few days, likely reaching the northern Gulf coast by mid-week. Upper- level winds are currently unfavorable for tropical development, but could become somewhat conducive for formation before it reaches the coast. Aside from this low pressure, high pressure will bring light to gentle winds and slight seas into mid-week. CARIBBEAN SEA... See the Tropical Waves section above for details on the tropical wave moving into the western Caribbean. Scattered moderate convection is noted over eastern Cuba and adjacent waters, while activity previously over the northwest Caribbean has diminished early this morning. Generally dry air and high pressure dominate the rest of the basin, with moderate to fresh trades ongoing. Seas are generally 3 to 5 ft, except 5 to 7 ft offshore Colombia. Swell from distance hurricane Larry is beginning to enter Atlantic passages off the Leeward Islands, where seas of 5 to 7 ft are occurring. For the forecast, major Hurricane Larry will remain well to the northeast of the Leeward Islands today, then move farther north of the area through mid week. Associated rough seas east of Leeward Islands and Atlantic entrances will persist into mid week. 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 Category 3 Hurricane Larry. Mid and upper level divergence is leading to scattered moderate to isolated strong convection over the Bahamas, otherwise generally high pressure dominates the basin outside of Major Hurricane Larry. A 1018 mb high pressure is centered near 27N62W, and a 1019 mb high pressure center is noted near 27N40W. Thus, generally outside of Larry, light to gentle wind prevails with seas of 3 to 6 ft. To the S and E of Larry, generally S of 20N and E of 50W, moderate to fresh NE trades prevail. Also, a weakening cold front is noted in the northeast basin, from 30N18W to 27N27W to 30N37W. No convection is associated with this front, and winds north of the boundary are N and gentle to moderate. For the forecast, Major Hurricane Larry will move to 22.6N 53.6W this afternoon, 23.9N 54.9W Tue morning, 25.3N 56.2W Tue afternoon, 26.8N 57.5W Wed morning, 28.5N 59.0W Wed afternoon, and 30.6N 60.6W Thu morning. Larry will change little in intensity as it moves to the northeast of Bermuda early Fri. Large swell and rough seas generated by Larry will continue to propagate across waters northeast of the Leeward Islands and spread west of 65W today, the perhaps reach 70W by mid week. $$ KONARIK