000 AXPZ20 KNHC 311550 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1550 UTC Thu Aug 31 2017 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Tropical Storm Lidia is centered near 22.3N 109.7W at 31/1500 UTC or about 40 nm SSE of Cabo San Lucas, Mexico moving NNW at 8 kt. Estimated minimum pressure is 997 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Numerous moderate and isolated strong convection is within 120 nm of the center. This convection is resulting in very heavy rainfall creating the potential for life-threatening flash floods and mudslides. Very large seas and swells will continue to impact Baja California and the W central coast of Mexico, spreading northward into the Gulf of California. Lidia is forecast to strengthen through this evening as it continues to approach the southern tip of Baja California, then is forecast to weaken as it continues to the NNW along or inland over the Baja California peninsula, becoming a remnant low by early Sun. Please see the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is N of 10N along 92W moving W at 10 to 15 kt. Scattered moderate convection is from 09N to 11N between 95W and 100W. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N84W to 16N105W, then resumes from 16N120W to 14N121W to low pressure near 12N134W to 10N140W. Scattered moderate and isolated strong convection is within 120 nm of the low pressure near 12N134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section for information on Tropical Storm Lidia located S of the southern tip of the Baja California Peninsula. Elsewhere, a ridge axis extends toward the northern offshore waters just W of 120W supporting mainly moderate NW to N flow across the open waters W of the Baja California Peninsula outside of the influence of Lidia. In the Gulf of Tehuantepec, light offshore nocturnal flow is expected through the upcoming weekend and into early next week, with light to gentle onshore flow during the day. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, gentle offshore nocturnal flow is expected through the remainder of the week, pulsing to moderate to fresh Sat night and Sun night. Otherwise, light and variable flow is expected N of the monsoon trough, while moderate to locally fresh southerly winds are expected S of the monsoon trough. Seas will be mainly 4 to 6 ft in mixed cross-equatorial southerly swell, as well as some long period NW swell. REMAINDER OF THE AREA... Recent altimeter data confirms northerly swells generated from strong winds off the coast of California are propagating into the discussion area N of 29N between 120W and 125W with seas to 8 ft. This swell will subside by the start of the upcoming weekend. Cross-equatorial southerly swell is breaching the equator and will hang around near the equator through the start of the upcoming weekend with seas up to 7 to 9 ft. Another area of southerly swell to 8 ft lingers just S of the monsoon trough thanks to moderate to fresh flow. These seas will subside to less than 8 ft this weekend. Otherwise, weak ridging dominating the waters W of 120W will support moderate to locally fresh trades and 4 to 7 ft through the next several days. $$ Christensen