000 AXPZ20 KNHC 221553 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Oct 22 2021 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A new tropical depression has formed SW of southern Mexico and it is forecast to strengthen to a hurricane over the next couple of days. AT 22/1500 UTC, Tropical Depression Seventeen-E is centered near 12.7N 100.5W moving W at 9 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. On the forecast track, the system would be approaching the coast of southwestern Mexico early next week. Strengthening is forecast, and the depression is expected to become a tropical storm by tonight, and a hurricane over the weekend. Tropical Depression Seventeen will produce 5 to 10 inches of rain with isolated storm total amounts of 15 inches across coastal sections of the Mexican states of Guerrero, Michoacan, and Colima starting Saturday night. This will likely produce flash flooding and mudslides. Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Tropical Depression Seventeen-E NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to Tropical Depression Seventeen-E located near 12.7N 100.5W to 11N110W to 1010 mb low pressure situated near 11N119W to 09N129W. The ITCZ continues from 09N129W to beyond 07N140W. Aside for the convection associated with Tropical Depression Seventeen-E, scattered moderate isolated strong convection is noted from 05N to 10N between 79W and 85W, near 11N89W, and from 07N to 13N between 105W and 130W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A new tropical depression has formed SW of southern Mexico. Please, see the Special Features section for more details. A surface ridge extends from 1022 mb high pressure centered near 26N132W to near the Revillagigedo Islands. Moderate to occasionally fresh NW winds persist between the ridge axis and lower pressure over north central Mexico. An altimeter pass confirmed 8 to 9 ft seas were already impacting the offshore waters of Baja California N of Cabo San Lazaro. This is part of a larger area of NW swell in excess of 8 ft propagating into the region. For the forecast, please, see the Special Features section for more details on Tropical Depression Seventeen-E. Elsewhere, NW swell in excess of 8 ft moving into the offshore waters of Baja California Norte will subside later today. However, another set of large NW swell will follow tonight, reach as far south as Socorro Island by Sun, then subside through late Mon. Looking ahead, a third round of NW swell may reach Baja California Norte waters Mon, reaching Socorro Island by Tue night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Mainly gentle to moderate S to SW will follow the monsoon trough as it lifts north of the area over the next couple of days. By Sat night into Sun, expect building seas in SW swell between Ecuador and the Galapagos Islands. This swell event is forecast to reach the offshore forecast waters of western Panama on Sun, supporting seas to 8 ft. Seas will subside thereafter across the region. REMAINDER OF THE AREA... A cold front is moving across the NW corner of the forecast region and extends from 30N130W to 27N140W. A 1022 mb high pressure centered near 26N132W is shifting east ahead of a cold front. Large, long period NW swells follow the front forecast to reach from 30N119W to 26N140W by Sat morning while weakening. Moderate to fresh SW winds are between the front and the high. Currently, seas of 8 to 12 ft in NW swell cover the area NW of a line from 30N128W to 25N140W. Highest seas of 12 to 15 ft are noted NW of a line from 30N132W to 27N140W. An altimeter pass just W of 140W confirmed the presence of these sea heights. This swell event will continue to propagate across the forecast region through at least Sat, with seas in excess of 8 ft covering much of the waters N of 20N W of 120W. Looking ahead, another large area of NW swell will move south of 30N Sun night, bring seas in excess of 8 ft to most of the area west of 110W through mid week. $$ GR