000 AXPZ20 KNHC 221623 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Oct 22 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... Dangerous Hurricane Willa is centered near 19.1N 107.2W at 1500 UTC moving N at 6 kt. Estimated minimum central pressure is 925 mb. Maximum sustained wind speed is 140 kt with gusts to 170 kt. A well defined 10 nm wide eye remains surrounded by intermittent strong convection within 60 nm across the N and 90 nm across the S semicircles, with scattered moderate to strong convection in bands elsewhere within 210 nm N and 360 nm S of the center. Some of these rain bands will bring very heavy rainfall along the Pacific coast of mainland Mexico from Michoacan to southern Sinaloa during the next 48 hours. Will is expected to continue northward today, then begin to gradually veer NE and across Las Tres Marias early Tue, then accelerate and move inland near Mazatlan Tue evening. Large swells generated by Willa will continue to reach the mainland Mexican coast between 102W and 108W through tonight, and will produce very large and powerful surf and cause life-threatening rip current conditions. Please refer to local forecasts from the Meteorological Service of Mexico for specific information on heavy rainfall and flash flood potential from Willa. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for additional details. Tropical Storm Vicente centered near 14.9N 100.8W at 1500 UTC moving WNW at 10 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered moderate to strong convection is occurring in bands within 120 nm N and 60 nm across the S semicircles. Vicente will continue on a general WNW track through the southern Mexican offshore waters today then turn more NW and gradually weaken through Tue evening as it approaches the Mexican coast near Manzanillo. 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 06N along 90W-91W. A broad 1010 mb surface low has develop in that area along the monsoon trough near 07N89W drifting W. Scattered moderate to strong convection continues along the monsoon trough associated with the wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia westward across Costa Rica near 09N84W to low pressure near 07N89W to 11N94W, where it breaks, then resumes SW of Hurricane Willa near 13N111W to surface low near 11.5N116.5W to 09N125W, where it transitions to ITCZ and continues on to beyond 11N140W. Widely scattered moderate isolated strong convection is observed within 60 nm N and 180 nm S of the trough and ITCZ west of 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features paragraph for details on Tropical Cyclones Vicente and Willa. W of the Baja California Peninsula...Gentle to locally moderate NW to N flow is expected through this evening when the pressure gradient will tighten, supporting moderate to locally fresh northerly flow W of the Baja California Peninsula on Tue into early Wed as Willa moves NE across Las Tres Marias and inland across southern Sinaloa. Large southerly swell from Hurricane Willa will propagate N through the waters W of Baja beginning this evening, and reaching as far N as 26N early Wed, before beginning to subside. Gulf of California: Light, mostly northerly flow is expected across the northern two-thirds of the Gulf through this afternoon when large southerly swell from Willa will propagate into the southern gulf waters, and then persist through late Tue night. Fresh to locally strong northerly winds are also expected across the gulf waters S of 24.5N late this afternoon into Wed as Willa passes just S of the Gulf entrance. Gulf of Tehuantepec...Fresh to locally strong northerly flow is expected through late this morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Pulses of fresh N to NE flow are forecast through Tue 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 flow, with 5 to 8 ft seas forecast through this afternoon, then mostly moderate SW flow and 4 to 7 ft seas are forecast through the middle of the week. REMAINDER OF THE AREA... Refer to the Special Features paragraph above for details on Tropical Cyclone Willa. A 1008 mb low near 11.5N116.5W will drift W for the next several days with fresh southerly flow, and 6 to 8 ft seas forecast within 300 nm SE of the low. This low has a low chance of becoming a tropical cyclone during the 5 days. A surface high will meander near 27N136W 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 from 12N to 22N W of 134W. These conditions will gradually shrink in areal coverage and shift W through Wed morning. $$ Stripling