000 AXPZ20 KNHC 080330 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 330 UTC Mon Oct 8 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 14.9N 127.9W at 08/0300 UTC or 1130 nm WSW of the southern tip of Baja California moving NW at 3 kt. Estimated minimum central pressure is 975 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Numerous moderate to scattered strong convection is noted within 90 nm in the southeast semicircle of the center of Sergio, with scattered moderate elsewhere within 150 nm of the center. 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 coast of Mexico 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 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 extensive SW flow into Central America is converging with NW flow along a line from 14N91W to 11N108W. This may be considered the monsoon trough, in the broadest sense of the definition. Scattered moderate to isolated strong convection is active within 60 nm either side of this line due the convergent NW and SW flow and rich moisture. Another segment of the monsoon trough reaches from 10N132W to 07N140W. ...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. Light to gentle onshore winds and seas of 5 to 8 ft in mixed southerly and westerly swell 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 in mainly the central and northern 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. Gentle to moderate SW flow with 4 to 6 ft seas will prevail into Panama and Costa Rica. 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 waters north of 20N through the early part of the week with N to NE flow around a building high pressure area northwest of the area supporting an increase to fresh to strong winds along and north 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. $$ Christensen