Eastern Pacific Tropical Weather Discussion
813 AXPZ20 KNHC 130312 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Oct 13 2026 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Hurricane Simon is centered near 20.4N 107.0W at 13/0300 UTC, moving west-northwest at 3 kt. Estimated minimum central pressure is 969 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Peak seas are near 20 ft. Numerous moderate to strong convection is within 45 nm of the center. Scattered to numerous moderate and isolated strong convection is elsewhere from 17N to 22N between 105W and 111W. Simon is moving slowly to the west- northwest and is forecast to continue moving slowly toward the northwest. Simon could approach the coast of western Mexico later this week. Simon is expected to produce rainfall totals of 5 to 10 inches across coastal west- central Mexico with isolated maximum amounts of 15 inches over the state of Sinaloa by Thursday. This rainfall will produce life- threatening flooding and mudslides or worsen any on- going flooding, especially in areas of steep terrain. Swells generated by Simon will affect portions of the coast of southwestern and west- central Mexico during the next few days, as well as the southern Gulf of California. These swells are likely to cause large and powerful surf and life- threatening rip current conditions. Please consult products from your local weather office. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Simon NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. South of Southern Mexico (EP93): Showers and thunderstorms are beginning to show signs of organization in association with a broad area of low pressure located several hundred miles south-southwest of the coast of Guatemala. This system is gradually becoming better defined, and environmental conditions are forecast to be conducive for further development. A tropical depression or tropical storm is expected to form well south of southern Mexico later tonight or tomorrow while the system moves generally west-northwestward at around 10 mph. There is a high chance for tropical cyclone development through next 48 hours. In anticipation of this system developing, a gale warning has been issued. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 08N110W. The ITCZ extends from 08N110W to 08N140W. Scattered moderate and isolated strong convection is noted from 00N to 10N E of 90W, and from 04N to 16N between 90W to 100W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on Hurricane Simon, and for a gale warning associated with EP93. Aside from conditions associated with Simon, fresh to locally strong winds are funneling through the Gulf of Tehuantepec in response to a deepening low pressure area (EP93) south of the area. Elsewhere, a stationary front extends from the northern Gulf of California across Baja California Norte to near 21N131W. Fresh SW winds are in the northern Gulf ahead of the front. Gentle to moderate winds, and slight to moderate seas, prevail elsewhere over the Gulf. Moderate to fresh winds and rough seas are north of the front. Gentle to moderate winds, and moderate to rough seas dominate the remainder of the discussion waters. For the forecast, Hurricane Simon is near 20.4N 107.0W at 8 PM PDT, and is moving west-northwest at 3 kt. Maximum sustained winds are 85 kt with gusts to 105 kt, and the minimum central pressure is 969 mb. Simon will move to 20.7N 107.3W Tue morning, 21.0N 107.7W Tue evening, 21.3N 108.0W Wed morning, 21.8N 108.0W Wed evening, 22.5N 107.9W Thu morning, and 23.2N 107.8W Thu evening. Simon will change little in intensity as it moves to near 24.0N 107.6W late Fri. A stationary front moving across the northern waters will gradually dissipate through Tue. Rough seas in NW swell west of Baja California will gradually diminish through early Wed. Elsewhere, showers and thunderstorms are beginning to show signs of organization in association with a broad area of low pressure located several hundred miles south- southwest of the coast of Guatemala. This system is gradually becoming better defined, and environmental conditions are forecast to be conducive for further development. A tropical depression or tropical storm is expected to form well south of southern Mexico later tonight or tomorrow while the system moves generally west- northwestward at around 10 mph. There is a high chance for tropical cyclone development through next 7 days. In anticipation of tropical cyclone development, a gale warning has been issued for portions of the waters south of southern Mexico. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong winds, and rough seas, associated with EP93 cover the waters well offshore Guatemala and El Salvador. Gentle to moderate winds, and moderate to locally rough seas, prevail over the remainder of the offshore waters. For the forecast, fresh to strong winds and rough associated with EP93 are impacting the waters well offshore Guatemala and El Salvador. These winds and seas will decrease through midweek as EP93 moves further from the area. Otherwise, a weak pressure gradient will support moderate or lighter winds, and moderate seas dominated by SW swell across much of the forecast waters through the end of the week. Numerous showers and thunderstorms are expected to remain active across the waters E of 85W through Tue then diminish significantly by early Wed. ...REMAINDER OF THE AREA... A stationary front extends across the NE waters from Baja California Norte to 21N131W. Moderate to fresh winds and rough seas of 7 to 10 ft in NW swell cover the waters N of 20N. Light to gentle winds and seas of 6 to 8 ft in merging NW and SW swell generally prevail elsewhere S of 20N W of 120W, except for moderate SE to S winds near the equator. For the forecast, the stationary front will gradually dissipate through Tue. Large SW swell will affect the waters S of the Equator and west of 105W over the next couple of days, followed by another pulse of large S-SW swell arriving into the waters W of 100W Wed night.