000 AXPZ20 KNHC 180409 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Sep 18 2022 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0250 UTC. ...SPECIAL FEATURES... The ill defined remnants of Tropical Depression Lester are estimated to be inland across interior portions of Guerrero, Mexico near 17.5N 99.5W. The remnants of Lester are forecast to continue to produce heavy rain across interior portions of Guerrero tonight. These rains may produce flash and urban flooding, along with possible mudslides in areas of higher coastal terrain. Tropical Storm Madeline is centered near 16.9N 106.8W at 18/0300 UTC moving N at 8 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered to numerous moderate to strong convection is noted within 360 nm W semicircle. A broad area of fresh to strong SW-W winds persists S and SE of this tropical cyclone, from 09N to 17N between 101W and 115W. This monsoonal SW wind flow has generated a broad area of high seas to the S and SE of Madeline, that continues to move NE towards the southwestern coast of Mexico. This will maintain very rough seas, large dangerous surf and strong rip currents along the coast of Mexico from Oaxaca to Cabo Corrientes through the weekend, and will spread northward and begin to affect the coast of Baja California Sur late Sun through early next week. Madeline is moving toward north and is expected to take a slow counter-clockwise turn toward the west Sunday through Tuesday. Slight strengthening is forecast for the next day or so, with fluctuations in intensity possible after that. Swells generated by Madeline will affect portions of the southwest coast of Mexico for the next few days. High surf associated with Madeline These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest T.S. Madeline NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N72.5W to 10N87W to 15N94.5W, then resumes from near 15N113W to 1011 mb low pressure located near 12N129.5W to 10N140W. Aside from the convection associated with Madeline, scattered moderate to strong convection can be found from N of 05.5N E of 87W, from 07N to 14N between 90W and 94W, within 240 nm of the Mexican coast between 96W and 104W, and from 19N to 22.5N E of 107W. Widely scattered moderate convection is noted within 120 nm S of the trough W of 113W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the Special Features section for details on T.S. Madeline. A broad ridge dominates the offshore of Baja California tonight producing moderate NW to N winds. Seas are generally in the 6-7 ft range, except 7-8 ft offshore of Baja Norte. Light to gentle winds and seas of 1-3 ft prevail in the Gulf of California. Marine conditions S of Cabo Corrientes are dominated by swell being generated by Tropical Storm Madeline. For the forecast, Tropical Storm Madeline will move N to NNW tonight and Sun, reaching near 19.2N 108.2W late Sun afternoon, and then begin to veer NW to W, reaching near 20.5N 110.6W late Mon afternoon, near 20.7N 113.0W late Tue afternoon, near 20.7W 115.5W late Wed afternoon, near 20.7W 118.4W late Thu afternoon, and near 20.7W 120.6W late Fri afternoon. Little change in overall strength is expected. A ridge will remain in place across the offshore waters of Baja California through the weekend and maintain moderate. Gentle to occasionally moderate mainly southerly winds and 1-3 ft seas are expected in the Gulf of California. Marine conditions will begin to deteriorate between Los Cabos and Cabo Corrientes early Sun as T.S. Madeline moves northward. Another area of low pressure is forecast to form south of the southern coast of Mexico by the middle of next week. Some gradual development is possible thereafter while the disturbance moves generally west-northwestward off the coast of southwestern Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate W-SW winds prevail south of the monsoon trough, except for an area of fresh SW winds well offshore of Costa Rica. Light and variable winds are north of the trough from the Gulf of Papagayo region to Guatemala coastal waters. Seas are 6-8 ft in SW swell across the offshore waters, with areas of 8-9 ft across the far outer offshore waters W of 87W. A moist and unstable environment interacting with the monsoon trough persists across the area. For the forecast, mainly gentle to moderate winds will persist across the offshore forecast waters, with seas of 6-9 ft in SW swell through Sun. A very moist and unstable atmospheric environment will help maintain active weather across most of the offshore waters over the next few days. An area of low pressure could form over the far eastern portion of the eastern North Pacific basin early next week. Environmental conditions are forecast to be conducive for some gradual development while the system moves west-northwestward near or offshore the coast. REMAINDER OF THE AREA... Refer to the Special Features section for details on T.S. Madeline. High pressure dominates the waters north of the monsoon trough and west of about 118W, centered on a 1032 mb high near 46N154W. The pressure gradient between this system and the monsoon trough supports an area of fresh NE winds from 11N to 19N W of 126W. Seas are 7-8 ft within these winds. Gentle to moderate winds prevail elsewhere north of the monsoon trough. Moderate to locally fresh southerly winds are south of the monsoon trough along with 5-8 ft seas, outside of T.S. Madeline. Cross equatorial SW swell continues to move into the region and is maintaining seas of 6-8 ft to the south of the monsoon trough and west of the Galapagos Islands. For the forecast, high pressure will continue to dominate the northern forecast waters. A weak cold front is forecast to enter the discussion area on Sun, extending roughly from 30N125W to 26N135W to 27N140W by Sun night. Seas of 8-10 ft in northerly swell will follow the front reaching the waters N of 27N and W of 126W by Mon morning. Additional pulses of cross-equatorial SW swell will continue to propagate across the forecast waters east of 130W. $$ Stripling