000 AXPZ20 KNHC 062059 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2059 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 1800 UTC surface analysis and satellite imagery through 2030 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 14.6N 124.7W at 06/2100 UTC or 980 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 75 nm in the NE quadrant, 150 nm in the SE quadrant, and 105 nm in the W semicircle of Sergio. Scattered moderate to strong convection is elsewhere within 210 nm of the center of Sergio. Large swells associated with Sergio will continue to mix with long period NW swell creating confused seas across a large portion of the discussion waters, with the swell also continuing to impact the SW coast of Mexico and Pacific coast of Baja California the next several days. In the Gulf of California, a tight pressure gradient will develop from around 29.5N to 30.5N in the next few hours 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. A broad area of low pressure, called a Central American Gyre, will transport abundant moisture into portions of Central America. This will produce heavy rainfall across western Nicaragua, Honduras, El Salvador, the coast of Guatemala, and the state of Chiapas in Mexico. These rains are expected to continue across portions of Central America for the next few days, resulting in flash floods and mudslides in areas of mountainous terrain. Refer to your local meteorological service for specific information on this potentially dangerous weather pattern. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 13.5N90W to 12N96W to 13N102W to 12N108W to 16N117W, then resumes from 11N125W to 09N130W to 09N140W. Scattered moderate and isolated strong convection is from 10N to 14.5N between 86W and 93W, from 08N to 12N between 93W and 98W, and also from 12N to 16.5N between 98W and 101W. Scattered moderate convection is from 08N to 11N between 101W and 104W, within 60 nm either side of the axis between 107W and 112W, from 06N to 08N between 125W and 129W, and also from 06.5N to 08N between 131W and 133W. ...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. In the Gulf of Tehuantepec, fresh to strong gap winds have diminished and lingering residual fresh swell to 8 ft will subside in the next few hours. 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 through early next week, with light and gentle onshore winds and seas of 5 to 8 ft E of 110W. Conditions are forecast to rapidly deteriorate across the Baja California Sur waters as Sergio draws closer by the middle of next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please refer to the Special Features section for additional details on the heavy rainfall potential over Central America. Fresh to strong SW monsoonal flow, and 8 to 11 ft seas, are expected over the offshore waters roughly from 08N to 13N and E of 95W the next couple of days, in response to the Central American Gyre discussed more in the Special Features section. The associated winds and seas will gradually diminish and subside the next few days, while the threat for heavy rainfall continues. 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