000 AXPZ20 KNHC 200939 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Tropical Storm Madeline is centered near 21.2N 111.3W at 0900 UTC moving W at 7 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Maximum seas at this time are estimated at 15 ft. Scattered moderate convection is seen within 360 nm NW and 180 nm SW semicircles. Strong upper level easterly winds continue to displace weakening convection well to the west of the center tonight, and this trend is expected to continue. A westward motion and gradual weakening is therefore forecast, as Madeline is expected to become a tropical depression around midday Tue, and a 25 kt post-tropical 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 portions of the Gulf of California during the next 24 hours. These swells will 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 14N78W to 12N88W to 17N100W, then resumes near 16n114w to low pres 1010 mb near 14.5N122W to 14.5N132W to 10N140W. Aside from the convection associated with Madeline, scattered moderate isolated strong convection is noted from 03.5N to 081N E of 86W. Scattered moderate to strong convection is noted from 11N to 18N between 87W and 103W, and from 10N to 15N between 100W 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 is bridging across a weak cold front that is NW of the area, and extends southeastward 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 fresh NW to N winds from Puerto Magdalena northward, and strong cyclonic winds offshore of Baja Sur. Seas are generally 6-8 ft in NW swell, 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 southerly winds and seas of 2-4 ft prevail elsewhere in the Gulf of California. Wind conditions across the near and offshore waters from Sinaloa to Colima have improved in recent hours as Madeline is moving W and away from the Mexican coast. Fresh southerly winds prevail from Cabo Corrientes into the Gulf through sunrise. 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 continue moving westward through Wed and slowly weaken, reaching near 21.3N 112.4W midday Tue as a tropical depression, reach near 21.5N 113.7W Tue night as a 25 kt post-tropical cyclone, reach near 21.5N 116.6W Wed night, then continue westward around 7 kt into the open Pacific through the end of the week. 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 late 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 Fonseca to Tehuantepec. Seas are 6-8 ft in S swell across the offshore waters, with mixed W swell across the waters W of 88W. For the forecast, moderate monsoonal winds will persist across the offshore forecast waters through Thu. Seas of 6-8 ft in S swell will continue 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 30N121W to 23.54N140W. Gentle to moderate northerly winds follow the front, with seas of 7-8 ft in NW swell. High pressure NW of the front is bridging across the weak boundary and extends SE to the west of Madeline and north of the monsoon trough. 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 S to SW winds are south of the monsoon trough. Cross equatorial S swell continues to move into the region and producing seas of 6-7 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. Northerly swell behind the cold front will 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, and raise seas to 8 ft along the equator Wed evening. 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 and seas of 8 to 10 ft just ahead of it. $$ Stripling