000 AXPZ20 KNHC 161608 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1453 UTC Fri Feb 16 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... Ashfall Advisory: The Fuego Volcano over S Guatemala near 14.5N 90.9W has resumed erupting. A plume of volcanic ash may reach to the surface through this 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 08N82W to 04N96W to low pres 1013 mb near 04N103W to 04N106W. The ITCZ continues from 05N109W to 05N119W to 08N132W to beyond 09N140W. No significant convection is currently associated with the ITCZ. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure N of the area and weak troughing over NW Mexico is maintaining gentle to moderate NW winds across much of the area. A surface trough associated with deep layer troughing stretches from 23N120W to low pres 1013 mb centered near 21N122W to 18N125W. The low will weaken during the next 24-48 hours as the associated mid to upper-level trough weakens and lifts out to the NE. Scattered showers associated with the trough will continue to advect NE across the waters adjacent to the Baja Peninsula. Gulf of Tehuantepec: A ridge over the Gulf of Mexico will continue weakening during the next 3 days. The high will remain strong enough to support fresh to strong winds over the Gulf for the next few days, primarily during nocturnal hours when drainage flow is prevalent. Gulf of California: Winds will become moderate northerly today as the pressure gradient tightens from strong high pressure to the NW. The gradient will then weaken this weekend as the high weakens, allowing conditions to improve. Looking ahead, a cold front will approach Baja California Norte Sun night, with SW winds in the northern Gulf expected to strengthen to around 25 kt ahead of the front. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong nocturnal NE to E winds will continue pulsing to 30 kt the next few nights. Downstream seas will build to 8-9 ft during the strongest winds each night. The area of high seas will merge with seas generated downstream from high winds in the Gulf of Tehuantepec through this afternoon. Gulf of Panama: Winds and seas will subside today as high pressure and strong winds in the SW Caribbean diminish, becoming moderate to fresh by this evening, as max seas subside from 8 ft to between 6 and 7 ft. Elsewhere, gentle to moderate offshore flow will prevail north of 09N, and light to gentle SSW winds will generally prevail south of 09N. REMAINDER OF THE AREA... Low pressure is centered near 21N122W with an associated surface trough extending through the low from 16N128W to 23N120W. A large area of cloudiness and showers associated with this system is displaced to the east of the surface trough axis. Scattered moderate and isolated strong convection is present from 11N to 17N between 115W and 120W. Coverage of cloudiness and showers is beginning to diminish as the associated deep layer trough weakens and lifts out to the NE. A tight pressure gradient between the trough and strong high pressure centered well NNW of the area is supporting fresh to strong NE winds from 22N to 25N between 127W and 134W, with seas of 8 to 10 ft. The pressure gradient between the high and lower pressure associated with the convergence zone is supporting fresh trades elsewhere, generally between 15N and 25N west of 115W. Seas are 6 to 8 ft in mixed NE and NW swell. Trade winds will slowly diminish as the high centered NW of the discussion area weakens, and allow residual seas to steadily diminish into this weekend. $$ CAM