000 AXPZ20 KNHC 072042 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2042 UTC Sun Oct 7 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 14.7N 127.5W at 07/2100 UTC or 1110 nm WSW of the southern tip of Baja California moving W at 6 kt. Estimated minimum central pressure is 971 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Numerous moderate and scattered strong convection is within 150 nm of the center of Sergio. Scattered moderate convection is from 13N to 16N between 119W and 122W, and also in a band between 330 nm and 420 nm in the SE quadrant 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. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for more details. Enhanced SW monsoon flow driven by a broad area of low pressure, called a Central American Gyre, will continue to transport abundant moisture into portions of Central America. This will produce heavy rainfall across Nicaragua, Honduras, El Salvador, and the coast of Guatemala. These rains may cause flash floods and mudslides in areas of mountainous terrain. The heavy rainfall threat is expected to shift northward later today through the early part of the week. 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 the coast of Guatemala near 15N92W to 13N100W to 10N110W, then resumes from 10N130W to 07N140W. Scattered moderate and isolated strong convection is within 180 nm S of the axis between 88W and 95W, and also between 100W and 110W. Similar convection is within 120 nm N of the axis between 95W and 100W, and also from 05N to 08N between 133W and 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Hurricane Sergio. In the northern Gulf of California, the tail end of a dissipating cold front is moving into mainland Mexico with the nearby pressure gradient now relaxing. 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. Light to gentle onshore winds and seas of 5 to 8 ft will prevail E of 110W. Conditions are forecast to rapidly deteriorate across the Baja California waters as Sergio moves closer to the forecast waters by the middle of the week, with conditions also deteriorating the Gulf of California by the end of the 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 10 ft seas, are expected over the offshore waters roughly from 07N to 15N between 85W and 108W the next couple of days, in response to a Central American Gyre discussed more in the Special Features section above. The associated conditions will gradually improve thereafter through the middle of the week. 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 through the early part of the 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. Conditions are likely to improve by the end of the week as Sergio moves E of 120W. $$ Lewitsky