526 AXPZ20 KNHC 040330 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Oct 4 2018 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Hurricane Sergio is centered near 13.8N 118.3W 948 MB at 0300 UTC, well SW of Baja California, moving NW at 8 kt. Maximum sustained winds are 115 kt with gusts to 140 kt. Some modest strengthening is expected during the next 24 hours as Sergio continues to move NW. Numerous moderate to strong convection is within 120 nm of the center, while bands of scattered moderate to strong convection are occurring elsewhere within 150 nm N and 270 nm S of center. A 30 nm wide eye has continued this evening. Large swell generated from Sergio will impact the Pacific coasts of Mexico and southern California during the remainder of this week. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 10N91W to 13N100W to 14N112W, then resumes west of Sergio from 12N125W to 10N132W to 10N140W. Scattered moderate isolated strong convection is from 07N to 11N between 86W and 94W, and within 45 nm either side of the trough axis west of 126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features above for information on the impacts of Hurricane Sergio. A stationary front extends from 31N120W to 20N131W. The front will become diffuse by the time it reaches the Baja Peninsula Thu evening. Building high pressure behind the boundary will strengthen NW winds by late Thu, with building seas in NW swell. Southerly swell from Sergio will also move into the region to further increase sea heights. Large dangerous surf will dominate the coastal zones into the weekend, including the entrance to the Gulf of California. Gentle Nw to W winds will prevail across most of the Gulf of California tonight. As high pressure builds across the area Thu night and Fri, NW winds will freshen across the Gulf. Moderate NW winds generally prevail across the waters between Cabo San Lucas and the Gulf of Tehuantepec for the next few days, while large SE swell from Sergio dominates area seas. In the Gulf of Tehuantepec, offshore northerly gap winds of 20 to 25 kt may pulse to 25-30 kt during overnight hours through Fri. Seas will reach 9-10 ft during period of strongest winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 09N and 12N, with fresh to strong southwesterly flow and building seas to 9 ft expected S of the monsoon trough E of 100W through Sat as a broad low pressure area develops across the western Caribbean and Central America. REMAINDER OF THE AREA... See Special Features above for information on Hurricane Sergio. As mentioned above, a stationary front is across the northern waters. The front will gradually become diffuse during the next 24 hours, and the remnants of the front are expected to shift eastward across Baja California Norte late Thu. A frontal trough is W of the dying front from 30N127W to 27N131W. NW swell behind the trough will build seas to 9-10 ft through Thu, then merge with the large and growing area of mixed swell associated with Hurricane Sergio by Fri. $$ Mundell