000 AXPZ20 KNHC 060242 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 039 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 15.3N 122.7W at 06/0300 UTC or 860 nm WSW of the southern tip of Baja California moving SW at 6 kt. Estimated minimum central pressure is 951 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Numerous moderate to strong convection is noted within 90 nm of the center. Scattered moderate and isolated strong convection is noted elsewhere from 11N to 18N between 118W and 125W. 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 12N87W to low pressure near 11.5N87.5W to 14.5N100W to 14.5N111W, then resumes from 11N124W to 09N130W to 10N140W. Scattered moderate and isolated strong convection is from 09N to 14N between 86W and 90W, from 07N to 13N between 92W and 101W, from 12N to 18N between 106W and 110W, and from 09N to 12N between 135W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Hurricane Sergio and 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, 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... 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 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. Also typical of these features are smaller centers of low pressure embedded within the broad gyre. One of these low pressure centers is located over the far eastern north Pacific waters near 11.5N87.5W. Scattered moderate and isolated strong convection around this embedded area of low pressure is noted above in the monsoon trough section. 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. $$ AL