000 AXPZ20 KNHC 222138 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2138 UTC Thu Feb 22 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 evening N of 14N and E of 93W. 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 from 09N84W to 02N96W. The ITCZ axis continues westward from 02N96W to 04N120W to 07N140W. Scattered moderate convection is within an area bounded by 14N126W to 09N124W to 07N133W to 09N140W to 13N140W to 12N135W to 14N126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... In the Gulf of Tehuantepec, northerly winds will briefly increase to 20-25 kt late tonight through Fri morning before diminishing, with seas briefly peaking at 7-8 ft during the event. A weakening cold front is pushing across the northern Gulf of California and Baja California Norte. Only light to moderate winds are following the front, however, a new cold front or trough will also move into the area by Fri evening. Northerly winds behind that next boundary will increase to fresh to strong by Fri evening and will spread southward across the Gulf through Sat afternoon, with fresh to occasionally strong winds then persisting across the central and southern Gulf through early next week. Seas will also build to 5-7 ft during the stronger winds. High pressure N of the area will continue to support moderate NW to N winds W of the Baja Peninsula accompanied by NW swell of 5- 8 ft N of 17N this evening. This area of swell will decay through Fri. Reinforcing high pres behind a new cold front or trough will bring fresh to locally strong NW winds W of Baja California Norte by Fri afternoon, spreading southward Fri night and Sat, with seas reaching to 8-9 ft. Conditions will improve for the second half of the weekend into early next week. 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 through and downstream of the Gulf of Papagayo to near 90W through Sat, then will pulse to fresh thereafter. Seas will build to 8 ft through early Fri, then will peak around 7 ft thereafter. In the Gulf of Panama, northerly flow will pulse to fresh levels during the overnight and early morning hours through Sat morning. Elsewhere, gentle to moderate offshore flow will prevail N of 05N while light to gentle SW winds are forecast S of 05N. REMAINDER OF THE AREA... Strong high pres extending from well NW of the area will continue to support fresh to strong trade winds across the waters N of the convergence zone and W of 115W through the next several days. A surrounding area of seas of 8-12 ft in mixed fresh NE swell and longer period NW swell will also persist. A reinforcing set of northerly swell will drop S of 32N Fri afternoon through the weekend, generated by gale force winds N of the area offshore of California NW of Cape Mendocino. $$ Lewitsky