000 AXPZ20 KNHC 230358 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0345 UTC. ...SPECIAL FEATURE...The Fuego Volcano at 14.5N 90.9W inland over Southern Guatemala is erupting. A plume of volcanic ash may reach to the surface across the Pacific waters N of 14N and E of 93W. Low level visibilities may be reduced to 3 nm or less. 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 at 10N84W to 04N93W where scatterometer winds indicate a transition to an ITCZ, which continues W to 03N102W to beyond 07N140W. Isolated moderate to strong convection is flaring within an area bounded by 10N140W to 18N114W to 15N106W to 06N137W to 07N140W to 10N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A W to E ridge extends across the area from 23N116W to 14N99W. Moderate to fresh northerly winds are observed W of the Baja Peninsula with seas of 5 to 8 ft. Strengthening high pressure will push fresh to locally strong NW winds, with 7 to 10 ft seas W of Baja California Norte by Fri afternoon, with these conditions spreading southward to along 24N early Sat before beginning to diminish. Associated seas should subside to less than 8 ft by early Mon, with another batch of strong NW winds and large NW swell arriving at 30N120W early Tue. Gulf of Tehuantepec: northerly winds will briefly increase to 20 to 25 kt late tonight through Fri morning before diminishing, with seas briefly peaking at 7 to 8 ft during this event. Gulf of California: Light to moderate northerly winds are expected across the entire gulf waters tonight into Fri. Strengthening high pressure will develop fresh to strong NW winds across the far northern waters late Fri, with these conditions spreading southward across the central gulf waters on Sat. Strong NW winds forecast across the waters S of 28.5N on Sat evening, with seas building to 8 ft. The pressure gradient will relax on Mon, with winds gradually clocking to S except increasing to strong along 30N on Mon night ahead of the next cold front. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong NE winds will continue to pulse through and downstream of the Gulf of Papagayo through this Tue night, with seas building to 8 ft as downstream as 10N91W. Gulf of Panama: Fresh nocturnal N winds are expected across the western Gulf of Panama overnight and again on Fri night with these conditions extending as far S as 05N80W. Mostly moderate nocturnal drainage flow is then forecast on Sat and Sun nights with fresh 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 7 to 11 ft seas, across the tropical waters N of the convergence zone and W of 112W through the upcoming weekend when the pressure gradient is forecast to further tighten. A batch of northerly swell in the form of 7 to 11 ft seas, will propagate S of 32N on Fri reaching along 22N between 115W and 130W on Sat before beginning to subside. Strong northerly winds will reach along 32N between 123W and 132W late Mon and spread S along 27N early Tue. $$ Nelson