000 AXNT20 KNHC 170604 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Sep 17 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 0000 UTC surface analysis and satellite imagery through 0540 UTC. ...SPECIAL FEATURES... The center of Post-Tropical Cyclone Lee, at 17/0600 UTC, is near 45.9N 64.8W. Lee is about 8 nm/15 km to the SW of Moncton in New Brunswick. Lee is moving toward the NNE, or 030 degrees, 12 knots. The estimated minimum central pressure is 983 mb. The maximum sustained wind speeds are 50 knots with gusts to 60 knots. The hazards that will be affecting land are: wind, surf, rainfall, and the storm surge. Tropical storm-force winds are: within 190 nm of the center in the NE quadrant; within 250 nm of the center in the SE quadrant; within 120 nm of the center in the SW quadrant; and within 80 nm of the center in the NW quadrant. Sea heights that are 12 feet or higher are: 480 nm of the center in the NE quadrant; within 660 nm of the center in the SE quadrant; within 570 nm of the center in the SW quadrant; and within 0 nm of the center in the NW quadrant. The maximum sea heights are 36 feet. All the precipitation is from 36N northward from 70W westward. A frontal boundary passes through Bermuda, beyond SE coastal Georgia. Precipitation: isolated moderate to locally strong is from 20N northward from 60W westward. The center of Tropical Storm Margot, at 17/0300 UTC, is near 33.9N 40.5W. Margot is moving toward the W, or 260 degrees, 07 knots. The estimated minimum central pressure is 999 mb. The maximum sustained wind speeds are 40 knots with gusts to 50 knots. Tropical storm-force winds are: within 160 nm of the center in the NE quadrant; within 90 nm of the center in the SE quadrant; within 70 nm of the center in the SW quadrant; and within 160 nm of the center in the NW quadrant. The radius of the sea heights that are 12 feet or greater is: within 330 nm of the center in the NE quadrant; within 210 nm of the center in the SE quadrant; within 270 nm of the center in the SW quadrant; and within 360 nm of the center in the NW quadrant. The maximum sea heights are 20 feet. Swells, that are being generated by Margot, will continue to affect the Azores for the next several days. It is likely for the swells to cause life-threatening surf and rip current conditions. Please, consult bulletins and charts from your local weather bureau office. Gradual weakening is forecast during the next couple of days. Slight fluctuations in intensity are possible. The deep convective precipitation that was associated with Margot has dissipated. The center of Tropical Storm Nigel, at 17/0300 UTC, is near 22.0N 48.0W. Nigel is moving toward the NW, or 325 degrees, 14 knots. The estimated minimum central pressure is 1005 mb. The maximum sustained wind speeds are 35 knots with gusts to 45 knots. Tropical storm-force winds are: within 80 nm of the center in the NE quadrant; within 0 nm of the center in the SE quadrant; within 0 nm of the center in the SW quadrant; and within 60 nm of the center in the NW quadrant. The radius of the sea heights that are 12 feet or greater is: within 120 nm of the center in the NE quadrant; within 60 nm of the center in the SE quadrant; within 60 nm of the center in the SW quadrant; and within 90 nm of the center in the NW quadrant. The maximum sea heights are 14 feet. Expect E winds 20 knots to 33 knots, and sea heights from 11 feet to 13 feet within 23N47W to 24N49W to 23N49W to 22N49W to 21N49W to 22N47W to 23N47W. Expect also winds 20 knots or less, and sea heights from 8 feet to 10 feet in mixed swell, within 25N42W to 28N49W to 25N52W to 19N51W to 18N47W to 20N42W to 25N42W. Precipitation: scattered to numerous strong is within 240 nm of the center in the NE semicircle. Isolated moderate to locally strong is in the remainder of the area that is from 20N southward between 40W and 58W. Please, visit www.hurricanes.gov, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 34W/35W, from 12N southward, moving westward 10 knots to 15 knots. Precipitation: widely scattered to isolated strong is within 300 nm on either side of the monsoon trough/ITCZ, from 44W eastward, including within 360 nm to the west of the tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border of Senegal and Guinea-Bissau, to 09N20W and 07N32W. The ITCZ is along 04N/05N between 35W and 43W. Precipitation: widely scattered to isolated strong is within 300 nm on either side of the monsoon trough/ITCZ, from 44W eastward, including within 360 nm to the west of the tropical wave. isolated moderate to locally strong is in the remainder of the area that is from 20N southward from 60W eastward. ...GULF OF MEXICO... A weak inland stationary front passes through the U.S.A. coastal plains, from SE Georgia, to the upper Texas Gulf coast, and to south Texas. Precipitation: isolated moderate to locally strong is from 90W westward. An inland surface trough passes through southern Mexico, through the Isthmus of Tehuantepec, to the Yucatan Peninsula. Precipitation: isolated moderate to locally strong is within 90 nm on either side of the surface trough. One surface ridge passes through south central Georgia, through parts of Florida, toward the Yucatan Peninsula. A second surface ridge passes through the deep South of Texas, toward the Isthmus of Tehuantepec of southern Mexico. Weak upper level cyclonic wind flow spans the area. Precipitation: isolated moderate to locally strong is from 90W eastward. Light to gentle winds, and sea heights that range from 1 foot to 2 feet, cover most of the area. An exception is for mostly moderate to some fresh NE winds that are from 23N southward between 88W and 94W, on the NW and W side of the Yucatan Peninsula. A weak ridge across the central Gulf will dominate the basin through early Sun, supporting mainly light to gentle anticyclonic winds along with slight seas. A weak cold front is forecast to move off New Orleans and Mississippi into the N-central and NE Gulf Sun followed by N to NW moderate winds and isolated to scattered showers. The front is forecast to move E of the area by Sun night, with a reinforcing front Mon. A weak surface ridge will develop afterward, supporting gentle to moderate NE to E winds through Wed, freshening in the NE Gulf Thu. Otherwise, winds will pulse to moderate to fresh W-NW of the Yucatan Peninsula this evening and Sun evening. ...CARIBBEAN SEA... Mostly moderate and some fresh NE winds are in the eastern one-third of the area. Mostly fresh to some strong NE winds are from 16N southward between 70W and 78W. Moderate NE winds are in the remainder of the area that is between 70W and 80W. Gentle to moderate winds are in the rest of the Caribbean Sea. The sea heights: are reaching 5 feet from the coastal waters of SW Haiti to the coast of Colombia; range from 3 feet to 4 feet elsewhere from 80W eastward; 2 feet from 15N southward from 80W westward; 1 foot elsewhere. The monsoon trough is along 10N/11N from 73W in Colombia beyond Costa Rica. Precipitation: widely scattered moderate to isolated strong is from 13N southward from 80W westward. An upper level cyclonic circulation center is on top of Jamaica. Upper level cyclonic wind flow is from 70W westward. Precipitation: isolated moderate is elsewhere from 70W westward. The 24-hour rainfall totals in inches, for the period that ended at 17/0000 UTC, according to the MIATPTPAN, are: 0.98 in Guadeloupe. Northerly swell affecting the NE Caribbean Passages will gradually subside tonight, then is forecast to build again slightly there Sun night through Wed due to Tropical Storm Nigel, which is forecast to remain well NE of the area while strengthening. Otherwise, moderate to fresh trades will prevail across the Central Caribbean, locally fresh to strong off Colombia, while gentle to moderate winds will dominate elsewhere through the forecast period. ...ATLANTIC OCEAN... Please, read the SPECIAL FEATURES section, for details about Post-Tropical Cyclone Lee, Tropical Storm Margot, and Tropical Storm Nigel. An upper level cyclonic circulation center is near 26N58W. Precipitation: isolated moderate to locally strong is elsewhere from 20N northward between 50W and 60W, and away from T.S. Nigel. A cold front passes through 31N10W, to just to the south of the Canary Islands, beyond 31N29W. The sea heights are 8 feet and higher, from 30N20W northwestward. Fresh NE winds are to the north of the cold front. Mostly moderate to some fresh NE winds are elsewhere from 10N northward from 35W eastward. Precipitation: isolated moderate is from 20N northward from 40W eastward. Moderate or slower winds, and sea heights that range from 4 feet to 7 feet, are in the remainder of the Atlantic Ocean. Tropical Storm Nigel is near 22.0N 48.0W at 11 PM EDT, and is moving northwest at 14 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1005 mb. Nigel will move to 23.6N 49.2W Sun morning, 25.3N 50.6W Sun evening, strengthen to a hurricane near 26.7N 52.2W Mon morning, 27.8N 54.0W Mon evening, 29.4N 55.7W Tue morning, and 31.3N 56.7W Tue evening. Nigel will change little in intensity as it moves near 36.0N 55.6W late Wed. Otherwise, high pres will prevail across the waters through Sun. A weak cold front is forecast to move off the SE U.S. coast early on Mon with new high pres building down behind it. The front may stall and linger along 27N/28N through mid-week. $$ mt