000 AXPZ20 KNHC 052104 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2104 UTC Fri Oct 5 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 1800 UTC surface analysis and satellite imagery through 2030 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 15.7N 122.3W at 05/2100 UTC or 830 nm WSW of the southern tip of Baja California moving WSW at 6 kt. Estimated minimum central pressure is 955 mb. Maximum sustained wind speed is 105 kt with gusts to 130 kt. Numerous moderate and isolated strong convection is within 120 nm in the E semicircle and within 150 nm in the W semicircle of Sergio. Scattered moderate and isolated strong convection is in a band in the SE quadrant between 240 nm and 480 nm of the center of Sergio. Large swell generated from Sergio will impact the Pacific coast of Mexico and southern California through 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 Sat 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 Sat night, diminishing by Sun afternoon as the pressure gradient weakens. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pressure near 11.5N87.5W to 11N100W to 14N117W, then resumes from 13N125W to 10N130W to 10N140W. Scattered moderate and isolated strong convection is from 08N to 10N between 87W and 90W, from 07N to 15N between 91W and 101W, from 12N to 14N between 107W and 109W, and also from 09N to 12N to the W of 135W. Scattered moderate convection is from 08N to 11N between 127W and 130W, and also from 11N to 13N between 130W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Hurricane Sergio. 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, and 5 to 8 ft E of 110W. In the Gulf of Tehuantepec, fresh to strong gap winds will prevail through early Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Broad 1007 mb low pressure is near 11.5N87.5W with scattered moderate and isolated strong convection within 60 nm in the E semicircle and within 120 nm in the W semicircle. Fresh to strong SW monsoonal flow and 8 to 12 ft seas, are expected roughly from 06N to 12N and E of 95W the next few days in response to a larger and more 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 Honduras. 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. Elsewhere, moderate to fresh trades will prevail outside of the influence of Sergio. 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