000 AXPZ20 KNHC 232051 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2051 UTC Fri Feb 23 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 2100 UTC. ...SPECIAL FEATURES... Ashfall Advisory: The Fuego Volcano at 14.5N 90.9W over S Guatemala is erupting. A plume of volcanic ash may reach to the surface through early Saturday N of 14N and E of 92W. Low level visibilities may be reduced to 1 nm. Mariners should exercise caution. If mariners encounter volcanic ash, they are encouraged to report the observation to the National Weather Service by calling 305-229-4425. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details on the ashfall advisory. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends SW from the Pacific coast of Costa Rica near 09N83W to 02N100W. The ITCZ axis continues from 02N100W to 05N120W to 07N140W. Scattered moderate and isolated strong convection is within an area bounded by 14N121W to 07N121W to 07N128W to 13N135W to 16N134W to 20N115W to 14N121W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... In the Gulf of Tehuantepec, fresh to strong northerly winds that were occurring this morning have diminished as the pressure gradient slackened. In the Gulf of California, light and variable winds in the northern Gulf prevail with moderate NW to N winds in the central and southern Gulf. Strengthening high pressure will develop fresh to strong NW winds across the far northern waters tonight with these conditions spreading southward across the central and southern Gulf by early Sat through Sat night. Seas may build to up to 8 ft during the strongest winds. The pressure gradient will relax on Sun and Mon. The next cold front will approach Mon night and winds will become southerly ahead of it in the northern Gulf while increasing to fresh to strong Mon night through Tue, with fresh northerly winds behind the front as it sinks southward through the early part of the week. Across the remainder of the open offshore waters of Mexico, strengthening high pressure is increasing winds to fresh to strong spreading S of 32N offshore of Baja California Norte. Seas are also in the process of building to 7-10 ft in fresh NW swell. The conditions will gradually spread southward offshore of Baja California through Sat morning, diminishing thereafter. The associated seas should subside to less than 8 ft by early Mon, with another round of fresh to strong NW winds, accompanied by large NW swell, arriving at 30N120W early Tue with the next cold front. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, fresh to strong NE winds will continue to pulse offshore across the Gulf of Papagayo through early next week, with seas occasionally building to 7-9 ft as downstream as 10N91W. Winds may briefly diminish during the afternoon hours each day. In the Gulf of Panama, fresh nocturnal N winds are expected across the western Gulf of Panama tonight with these conditions extending as far S as 05N80W. Mostly moderate nocturnal drainage flow is then forecast on Sat and Sun nights with fresh nocturnal winds expected to resume on Mon night. Elsewhere, gentle to moderate offshore flow will prevail N of 08N while light to gentle SW winds are forecast S of 08N. REMAINDER OF THE AREA... Strong high pressure well NW of the area will continue to support fresh to strong NE trades and seas up to 8-12 ft across the tropical waters N of the convergence zone and W of 110W through the weekend. A fresh batch of northerly swell in the form of 7-11 ft seas is propagating S of 32N, and will reaching along 22N between 115W and 130W on Sat before beginning to subside. $$ Lewitsky