514 AXPZ20 KNHC 040915 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Oct 4 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... Hurricane Marie is centered near 20.1N 128.1W at 04/0900 UTC moving NW at 7 kt. Estimated minimum central pressure is 967 mb. Maximum sustained wind speed is 90 kt with gusts to 110 kt. Satellite imagery shows numerous moderate to isolated strong convection from 19N to 21N between 127W and 129W. The hurricane is forecast to move generally northwestward or west-northwestward with little change in forward speed for the next few days. Marie should quickly weaken to a tropical storm by early Monday, with further weakening likely through the middle of the week. 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: Fresh to strong northerly winds between a ridge across the western Gulf of Mexico and T.S. Gamma now located just N of the Yucatan peninsula will continue to support a gap wind event across the Tehuantepec region. Gale force winds are expected to blow across the Gulf of Tehuantepec and downwind to near 13N-14N through Mon night. Seas will peak again near 15-16 ft Sun night into Mon morning. This gap wind event is forecast to persist through mid-week. 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. ...TROPICAL WAVES... A tropical wave extends along 96W N of 03N, moving W at 10-15 kt. Scattered moderate isolated strong convection is noted from 12N to 14N between 87W and 96W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N86W to 12N92W to 1008 mb low pres near 10.5N102.5W to 11N113W, then resumes W of Hurricane Marie near 12N125W to beyond 08N140W. Scattered moderate convection is observed from 04N to 06N E of 80W to the coast of Colombia, from 08N to 13N between 101W and 107W, and from 09N to 13N between 114W and 118W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section for more on the ongoing Gulf of Tehuantepec Gale Warning. Elsewhere, mainly light to gentle winds will dominate the offshore forecast waters of Baja California under a weak pressure gradient. A ridge will establish again over the area on Mon, bringing gentle to moderate NW winds, mainly offshore Baja California del Norte. Seas generated by Hurricane Marie will continue to spread across the waters W of Baja California today. Light to gentle southerly winds are expected in the Gulf of California into Tue. 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 winds in the Tehuantepec region will continue to propagate across the offshore waters of Guatemala and El Salvador into Tue. Looking ahead, an area of low pressure could form south-southeast of the Gulf of Tehuantepec early this week. Gradual development of this system is possible thereafter while it drifts northward offshore of the coasts of Mexico and Guatemala. This system has a low chance of tropical formation in the next 5 days. REMAINDER OF THE AREA... Please see Special Features section above for more information on Hurricane Marie that is rapidly weakening over cooler waters. Outside of Hurricane Marie, a ridge dominates the NW corner of the forecast area. The pressure gradient between this ridge and Marie is maintaining gentle to moderate winds N of the monsoon trough to about 28N, and gentle to moderate winds S of the monsoon trough. Currently, seas greater than 8 ft, generated by Marie cover most of the waters N of 10N and W of 115W. Long period SE swell from the Southern Hemisphere is forecast to reach the equator by early Mon. Showers and thunderstorms have become better organized in association with an elongated area of low pressure located several hundred miles south of the southwestern coast of Mexico. Environmental conditions appear conducive for additional development, and a tropical depression could form during the next few days while it moves slowly northwestward. This system has a medium chance of tropical cyclone formation through 48 hours. A recent scatterometer pass showed fresh to strong winds in association with this system located near 10.5N102.5W. Tropical Storm Gamma located just north of the Yucatan Peninsula is expected to produce heavy rainfall for several days over portions of southeastern Mexico, the Yucatan Peninsula, and Central America. This rainfall could result in life-threatening flash flooding and mudslides, particularly in the mountainous regions of southeastern Mexico and Central America. $$ GR