000 AXPZ20 KNHC 061459 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1459 UTC Sat Oct 6 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 1200 UTC surface analysis and satellite imagery through 1430 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 14.7N 124.0W at 06/1500 UTC or 940 nm WSW of the southern tip of Baja California moving WSW at 6 kt. Estimated minimum central pressure is 950 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Numerous moderate to strong convection is within 90 nm of the center of Sergio, except within 120 nm in the NE quadrant. Scattered moderate and isolated strong convection is elsewhere within 180 nm of the center of Sergio. Large swell generated from Sergio will impact the Pacific coast of Mexico and southern California this weekend. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for more details. In the Gulf of California, a tight pressure gradient will develop from around 29.5N to 30.5N late this afternoon and SW to W winds will rapidly increase to fresh to near gale force enhanced from gap wind flow in Baja California Norte. Winds will continue to increase to minimal gale force tonight, diminishing by Sun afternoon as the pressure gradient weakens. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pressure near the coast of El Salvador at 13N88.5W to 12N98W to 15N102W to 12N109W to 16N115W, then resumes from 12N126W to 09N130W to 09N140W. Scattered moderate and isolated strong convection is generally N of 09N between 86W and 100W. Scattered moderate convection is from 06N to 08N between 105W and 108W, from 11N to 14N between 107W and 109W, and also from 06N to 09N between 124W and 140W. Additional widely scattered moderate convection is between 105W and 109W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Hurricane Sergio and on a developing Gale Warning in the northern Gulf of California. Elsewhere, mainly moderate to fresh NW to N winds and mixed swells from Sergio and long period NW swell will support combined seas of 7 to 11 ft to the W of 110W building early next week, with light and gentle onshore winds and seas of 5 to 8 ft E of 110W. In the Gulf of Tehuantepec, fresh to strong gap winds will prevail through the next few hours. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong SW monsoonal flow, and 8 to 11 ft seas, are expected roughly from 08N to 13N and E of 95W the next couple of days in response to a broad area of low pressure over Central America, called a Central American Gyre. As is typical for these features, the associated long fetch of SW winds across the tropical Pacific will transport abundant moisture into portions of Central America, especially from Costa Rica to Guatemala. This will create the potential for significant rainfall over these areas through early next week. Refer to your local meteorological service for specific information on this potentially dangerous weather pattern. REMAINDER OF THE AREA... Please see the Special Features section for details on Hurricane Sergio. Outside the influence of Sergio, moderate to fresh trades will prevail. The pressure gradient will tighten across the northern waters early next week with N to NE flow around a deepening high NW of the area supporting an increase to fresh to strong winds along and N of 30N. Meanwhile, confused seas are likely to continue due to long period NW swell, and a large and expanding area of mixed swell associated with Sergio. $$ Lewitsky