000 AXPZ20 KNHC 200352 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 20 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... Tropical Storm Madeline is centered near 21N 110.8W at 0300 UTC moving WNW at 7 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Maximum seas at this time are estimated at 18 ft. Scattered to numerous moderate isolated strong within 180 nm W semicircle. Scattered moderate elsewhere from 16.5N TO 21N between 111W and 115W. Strong upper level easterly winds are displacing the convection to the west of the center tonight, and this trend is expected to continue. Gradual weakening is therefore forecast, and Madeline is expected to become a post-tropical 30 kt cyclone by early Wednesday. Southerly swell generated by Madeline will continue to spread northward across the waters of Baja California Sur, and inside the south and central Gulf of California during the next 24 hours. These swells continue to produce large and dangerous surf and life- threatening rip current conditions. Please consult products from your local weather office for more details. 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 13.5N73W to 11.5N88W to 17N102W, then resumes near 15.5N114.5W to low pres 1010 mb near 11.5N135W to beyond 10N140W. Aside from the convection associated with Madeline, scattered moderate isolated strong convection is noted from 01.5N to 11N E of 90W. Scattered moderate to strong convection is noted from 11N to 17N between 89W and 103W, and from 11N to 15N between 101W and 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the Special Features section for details on T.S. Madeline. A weak surface ridge extends eastward across the offshore waters of Baja California. The pressure gradient between higher pressure to the NW and lower pressure across Baja California and Madeline is producing moderate to locally NW to N winds from Puerto Magdalena northward, and strong cyclonic winds offshore of Baja Sur. Seas are generally in the 6-8 ft range, except 8 to 15 ft across the Baja Sur waters in swell from Madeline, and 6 to 9 ft across the southern Gulf of California. Light to gentle variable and seas of 2-4 ft prevail elsewhere in the Gulf of California. Wind conditions across the near and offshore waters from Sinaloa to Nayarit have improved in recent hours as Madeline is moving W-NW and away from the Mexican coast. Fresh to strong southerly winds prevail from Cabo Corrientes into the Gulf. Elsewhere, gentle to moderate mostly westerly winds prevail across the offshore waters between Cabo Corrientes and Tehuantepec, where seas are 7-9 ft in S to SW swell. For the forecast, Tropical Storm Madeline will begin to move westerly tonight and slowly weaken, reaching near 21.1N 111.9W Tue morning, and become post-tropical at 30 kt near 21.7N 114.6W Wed morning, reach near 21.7N 117.4W Thu morning, then continue westward into the upcoming weaken. The surface ridge will remain in place across the offshore waters of Baja California through the next few days and help to maintain the westward motion of Madeline. Winds and seas across the southern Gulf of California will gradually improve Tue as Madeline moves away. Another area of low pressure is forecast to form south of the southern coast of Mexico by midweek. 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... Moderate W to SW winds prevail south of the monsoon trough and light and variable winds are north of the trough from the Gulf of Papagayo region to Tehuantepec. Seas are 6-8 ft in S swell across the offshore waters, with mixed W swell across the waters W of 89W. For the forecast, moderate monsoonal winds will persist across the offshore forecast waters through Thu, with seas of 6-8 ft in S swell through tonight, before subsiding modestly through mid week. An area of low pressure could form between Papagayo and Tehuantepec during the next few days. Environmental conditions are forecast to be conducive for some gradual development while the system moves west-northwestward offshore of the coast. REMAINDER OF THE AREA... Refer to the Special Features section for details on T.S. Madeline. A weak cold front extends from 30N122W to 24N140W. Gentle to moderate northerly winds follow the front, with seas of 7-9 ft in NW swell. High pressure extends a weak ridge to the S of the front and then SE across the waters north of the monsoon trough and west of 120W. The pressure gradient between this system and the monsoon trough supports a small area of moderate NE winds from 15N to 19N W of 122W. Seas are 6-7 ft within these winds. Gentle to moderate winds prevail elsewhere north of the monsoon trough. Moderate to fresh southerly winds are south of the monsoon trough. Cross equatorial S 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. The cold front will continue to push southward to 24N-23N through early Wed while weakening. Seas of 8-9 ft in northerly swell will follow the front tonight then fade to 7 ft on Tue. Additional pulses of cross-equatorial S to SW swell will continue to propagate across the forecast waters east of 130W. As T.S. Madeline moves westward and gradually weakens through Thu, fresh to strong NE winds will remain across the NW semicircle of the low, and generate E to NE swell spreading ahead of it. $$ Stripling