000 AXPZ20 KNHC 170831 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0830 UTC Thu Oct 17 2019 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 0830 UTC. ...SPECIAL FEATURES... Heavy Rainfall Event for southern Mexico: SW monsoon flow will continue to advect abundant moisture over southern Mexico today. Heavy rainfall is possible over portions of southern Mexico from Chiapas to Jalisco. These rains could cause flooding and mudslides, especially in mountainous areas. Please monitor products from your local or national meteorological service for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 118W/119W, from 04N to 16N, moving W at 5-10 kt. Scattered moderate convection is noted from 09N to 11N between 119W and 122W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near 10N85W along the Pacific coasts of Nicaragua to El Salvador, Guatemala and Mexico to 17N96W to 10N112W to low pressure near 11.5N125.5W to 11N135W. Scattered moderate isolated strong convection is noted over waters N of 09N between 91W and 110W. Scattered moderate convection was noted from 08N to 10N between 127W and 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about a heavy rainfall event over southern Mexico. Moderate to fresh SW monsoonal flow and seas of 6-8 ft will persist S of the monsoon trough in the Gulf of Tehuantepec zone through the end of the week. Elsewhere, a ridge will build through the week across the Baja California offshore waters producing mainly a moderate NW to N wind flow. A set of large NW swell will propagate into the Baja California Norte offshore waters by the end of the week with seas of 8-12 ft, spreading SE and reaching the Revillagigedo Islands by Sat night and continuing through Sun night. This swell will gradually decay early next week. Looking ahead, the pressure gradient across the Gulf of California region will tighten early next week. This will allow NW flow to freshen, locally strong in the northern and central Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW-W winds with seas in the 4-6 ft range will prevail through Fri. SW swell will propagate into the southern waters Fri night. The swell will spread S to N across the forecast waters through the weekend. REMAINDER OF THE AREA... A ridge dominates mainly the waters N of 19N W of 120W. Scatterometer data indicates mainly gentle to moderate trades across this area under the ridge. Just to the S of the ridge, a trough is over the far W central waters along 139W from 11N to 17N. This trough will drift westward with an area of fresh to strong trades and seas of 8-9 ft. The trough will shift W of 140W tonight. A nearly stationary 1010 mb low pressure area is embedded in the monsoon trough near 11.5N125.5W. Scattered moderate and isolated strong convection is noted from 09N to 12N between 123W and 127W. An area of fresh to locally strong winds and seas to 8 ft is within 60 nm N semicircle of the low center. This low is forecast to linger in the same general area through the week with little change in winds and seas in the vicinity. A set of long period NW swell has propagated into the NW forecast waters, with seas of 8 to 9 ft affecting the waters NW of a line from 30N135W to 28N140W. This swell will continue to propagate SE-S through the end of the week, with seas of 8 ft or greater likely covering the waters N of 20N W of 110W, and from 10N to 20N W of 115W by Sat. The swell will slowly decay from NW to SE by the end of the upcoming weekend and into early next week. $$ AL