000 AXPZ20 KNHC 081600 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1448 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 1200 UTC surface analysis and satellite imagery through 1445 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 15.3N 128.6W at 08/1500 UTC or 1155 nm WSW of the southern tip of Baja California moving NNW at 2 kt. Estimated minimum central pressure is 975 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Numerous moderate and isolated strong convection is noted within 150 nm of the center. Scattered moderate and isolated strong convection is seen elsewhere between 12N and 18N between 119W and 132W. 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 adjacent coastal waters. 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 monsoon trough reaches from the Guatemala/Mexico border near 16N91W to 13N100W to 13N111W. The trough resumes from 10N132W to 08N137W to beyond 07N140W. Scattered moderate and isolated strong convection is evident from 09N to 17N between 89W and 106W. Scattered moderate convection is also occurring from 07N to 09N between 126W and 133W and from 04N to 07N W of 136W. ...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 as well as long period NW swell will support combined seas of 7 to 11 ft west of 110W for the next couple of days. Light to gentle onshore winds and seas of 5 to 8 ft in mixed southerly and westerly swell will prevail east of 110W. Conditions are forecast to rapidly deteriorate across the Baja California waters as Sergio moves closer to the forecast waters on Thu, with conditions also deteriorating for the central and northern Gulf of California Thu night. 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 regarding the heavy rainfall potential for 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 during the next couple of days, in response to the Central American Gyre discussed previously in the Special Features section above. The associated conditions will gradually improve thereafter through the middle of the week as the gyre weakens. Gentle to moderate SW flow with 4 to 6 ft seas will prevail for the waters of Panama and Costa Rica. REMAINDER OF THE AREA... Please see the Special Features section for details on Hurricane Sergio. Outside of the influence of Sergio, moderate to fresh trades will prevail. The pressure gradient will lessen across the waters north of 20N and W of 120W during the second half of the week as high pressure centered NW of the discussion area weakens. 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. Long period SW swell arriving from the Southern Hemisphere will also contribute to combined seas. $$ CAM