000 AXPZ20 KNHC 211617 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Oct 21 2018 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Hurricane Willa centered near 16.6N 106.7W at 1500 UTC moving NW at 6 kt. Estimated minimum central pressure is 975 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Currently numerous strong convection is observed within 75 nm N and 90 nm S of the center, surrounded by scattered moderate to strong convection in bands within 330 nm of the center. Some of these rain bands will bring very heavy rainfall to the Pacific coast of Mexico from Michoacan to Sinaloa. Willa is will make a gradual N turn during the next 24 hours and then veer more NE late Mon and Mon night, then cross Las Tres Marias Tue before entering the coasts of Sinaloa early Wed morning. Swells generated by Willa will begin to reach portions of the coast of southwestern and west-central Mexico this afternoon and tonight and will produce very large and power surf and life-threatening rip current conditions. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for additional details. Tropical Storm Vicente centered near 14.4N 96.8W at 1500 UTC moving WSW at 8 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed remains 45 kt with gusts to 55 kt. Scattered moderate to strong convection is observed in bands within 75 nm NE and 120 nm SW semicircle of the center. Vicente will continue on a general westward track through the southern Mexican offshore waters through Mon and then begin to veer NW and follow Willa, and move inland between Michoacan and Jalisco early Wed morning. The main threat of Vicente will be very heavy rainfall as it moves across the Mexican coastline across areas that will also receive torrential rainfall from Willa. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for additional details. ...TROPICAL WAVE... A tropical wave is analyzed N of 08N along 84W-85W. Scattered moderate to strong convection continues to flare along and east of the wave, from 04N TO 08N E of 85W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia at 10N76W to the Pacific coast of Costa Rica at 10N85W, then turns NW to near 12N92W where it loses identity to the east of Tropical Storm Vicente. The monsoon trough resumes SW of Hurricane Willa at 14N111W, and continues SW through an embedded surface low at 11N118W to 09N127W, then turns W-NW to beyond 10N140W. Scattered moderate to strong convection is observed within 60 nm N and 90 nm S of the trough westward of 127W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features paragraph for details on Tropical Cyclones Vicente and Willa. A ridge extends from a 1021 mb surface high near 35N136W through 30N130W to 21N111W and will retract to the W this afternoon. Gentle to locally moderate NW to N flow is expected N of 20N W of 110W through Mon night when the pressure gradient is forecast to tighten, supporting moderate northerly flow W of the Baja California Peninsula by the middle of the week. Additionally, large southerly swell from Hurricane Willa will propagate northward and into the waters between Cabo Corrientes and Baja California Sur tonight through Mon, and spread farther northward across the remaining Baja waters late Mon through Tue before beginning to subside Wed. Gulf of California: Light, mostly northerly flow is expected through late Mon across the Gulf. Large southerly swell from Hurricane Willa will begin to propagate into the southern gulf waters tonight and dominate seas through Wed. Fresh to locally strong northerly winds are expected across the gulf waters S of 24.5N on Tue night into Wed as Willa passes S of the gulf entrance. Bands of showers and thunderstorms associated with Willa will impact the coastal states from Jalisco to Sinaloa Mon and Tue ahead of the expected Wed landfall of Willa. Gulf of Tehuantepec...Fresh northerly winds, with 6 to 8 ft seas are forecast N of 15N today as Tropical Storm Vicente passes to the S. Fresh to locally strong northerly flow is expected to continue through Mon, with nocturnal drainage flow Mon night diminishing during the day on Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Pulses of fresh NE flow are forecast through Mon morning. Light northerly winds and 4 to 7 ft seas are forecast elsewhere N of the monsoon trough, while moderate to locally fresh southwesterly monsoonal wind flow, and seas of 5 to 8 ft in SW swell are expected through late Mon. REMAINDER OF THE AREA... Refer to the Special Features paragraph above for details on Tropical Cyclone Willa. A weak 1010 mb low will meander near 11N118W for the next few days with moderate southerly flow and 6 to 8 ft seas forecast within 180 nm SE of the low. A surface high will meander near 29N136W with moderate to locally fresh anticyclonic flow forecast across the tropical waters N of the monsoon trough and ITCZ, and W of 122W through the middle of the week. An area of 7 to 9 ft seas is observed across the tropical waters W of a line from 09N140W TO 12N130.5W TO 23N140W, in mixed ENE wind waves and other mixed swell. These conditions will gradually shrink in areal coverage and shift slowly W through Tue. $$ Stripling