000 AXPZ20 KNHC 020927 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Oct 2 2020 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Major Hurricane Marie is centered near 16.2N 123.2W at 02/0900 UTC moving WNW at 13 kt. A motion toward the west-northwest or northwest with a gradual decrease in forward speed is expected during the next several days. Estimated minimum central pressure is 947 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt. Marie is now a category 4 hurricane on the Saffir- Simpson Hurricane Wind Scale. Additional strengthening is expected today, with weakening forecast to begin on Saturday. Satellite imagery shows numerous moderate to strong convection within 90 nm of center. Similar convection is in a band from 12N to 15N between 121W and 124W. Scattered moderate isolated strong is seen elsewhere within 150 N and 210 NM S semicircles of center. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP3.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP3.shtml for more details. Gulf of Tehuantepec Gale Warning: A ridge across the western Gulf of Mexico and eastern slopes of the Sierra Madre Mountains in Mexico combined with a developing tropical disturbance in the NW Caribbean will continue to support fresh to strong northerly winds over the Bay of Campeche. These winds are funneling through the Chivela Pass into the Gulf of Tehuantepec, producing strong gale force winds of 35-40 kt in the Tehuantepec region. This gap wind event is forecast to persist through Sat, with minimal gale conditions prevailing through Mon night. Seas will peak near 14-17 ft during this event. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N86W to 09N105W, then resumes W of Hurricane Marie near 10N127W to 09N135W. The ITCZ is from 09N135W to 11N140W. Scattered moderate to isolated strong convection is noted from 07N to 13N between 85W and 90W, from 07N to 12N between 90W to 102W, and from 12N to 16N between 114W and 117W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the ongoing Gulf of Tehuantepec gap wind event. Elsewhere, mainly light to gentle winds will dominate the offshore forecast waters of Baja California under a weak pressure gradient. By Mon night, a ridge will establish again over the area, bringing gentle to moderate NW winds. Seas generated by Hurricane Marie will continue to spread across the waters W of Baja California through the upcoming weekend. Gentle southerly winds are expected in the Gulf of California through Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to locally fresh southwesterly winds are expected S of the monsoon trough with mainly light to gentle winds N of it. Seas generated by the gale-force gap wind event in the Tehuantepec region will propagate across the offshore waters of Guatemala and El Salvador through the next couple of days. REMAINDER OF THE AREA... Please see Special Features section above for more information on Hurricane Marie. Outside of Hurricane Marie, a weak ridge prevails over the NW corner of the forecast area. The pressure gradient between this ridge and Hurricane is maintaining gentle to moderate winds N of the monsoon trough to about 25N, and gentle to moderate winds S of the monsoon trough. An area of fresh to strong SW is noted based on scatterometer data to the S of Marie from 07N to 11N between 117W and 127W. The large size of Hurricane Marie will generate a large area of seas greater than 8 ft which will spread well away from the cyclone center. By Saturday, seas greater than 8 ft will cover much of the waters N of 10N and W of 115W. A broad area of low pressure is expected to form several hundred miles southwest of the coast of southwestern Mexico this weekend. Some development of this system is possible early next week while it moves west-northwestward at 5 to 10 kt. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation through 5 days. $$ GR