000 AXPZ20 KNHC 071514 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1514 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 1200 UTC surface analysis and satellite imagery through 1430 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 14.5N 126.8W at 07/1500 UTC or 1080 nm WSW of the southern tip of Baja California moving W at 7 kt. Estimated minimum central pressure is 967 mb. Maximum sustained wind speed is 90 kt with gusts to 110 kt. Numerous moderate to strong convection is within 120 nm of the center of Sergio, with scattered moderate and isolated strong convection elsewhere within 150 nm of the center of Sergio, except within 240 nm in the NE quadrant. Additional scattered moderate and isolated strong convection is from 12N to 16N between 119W and 122W and also from 06N to 09N between 125W and 129W. 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 western Nicaragua, Honduras, El Salvador, the coast of Guatemala, and the state of Chiapas in Mexico. 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 14.5N92W to 16N98W to 11N105W to 11N110W, then resumes from 10N130W to 07N140W. Scattered moderate and isolated strong convection is from 11N to 16N between 86W and 99W, and also within 120 nm either side of the axis between 100W and 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Hurricane Sergio. In the far northern Gulf of California, a tight pressure gradient enhancing gap wind flow across Baja California Norte is producing fresh to near gale force winds, however the minimal gale force winds that were occurring earlier have diminished. The pressure gradient will continue to weaken this morning, with winds diminishing below fresh to strong later today. 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 Sur waters as Sergio moves closer to the forecast waters by the middle of the week, and potentially the Baja California Norte waters 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 11 ft seas, are expected over the offshore waters roughly from 07N to 14N between 86W and 107W the next couple of days, in response to the 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