015 AXPZ20 KNHC 162142 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2142 UTC Thu Aug 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURE... Tropical Storm Lane centered near 10.6N 128.6W at 16/2100 UTC or 1620 nm ESE of Hilo Hawaii moving W at 11 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Numerous moderate and isolated strong convection is within 180 nm in the E semicircle, 270 nm in the SW quadrant, and 210 nm in the NW quadrant. Lane is forecast to become a hurricane late tonight, and is forecast to move W of 140W into the central Pacific Sat night. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCPEP4/WTPZ34 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends from the Yucatan Peninsula southward into the E Pacific along 90W, N of 06N, moving W at 10 to 15 kt. Scattered moderate and isolated strong convection is from 04N to 08N between 90W and 93W, and also from 10N to 14N between 90W and 94W. Scattered moderate convection is from 14N to 15N between 94W and 98W. A tropical wave extends from 07N114W to 15N109W moving W at 10 to 15 kt. Scattered moderate and isolated strong convection is within 120 nm SE and 90 nm NW of the tropical wave axis. Scattered moderate convection is from 08N to 10.5N between 107W and 112W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 07N77W to 09N84W to 07N96W to 10N105W to 11N119W. No ITCZ axis is noted E of 140W. Scattered moderate convection is from 07N to 11N between 101W and 104W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak surface ridging extends from W of the offshore waters area to the SE across the Revillagigedo Islands. A weak trough associated with the remnants of tropical cyclone John lingers across the coastal waters near Punta Eugenio, and is aiding in producing gentle N to NW winds across the near shore waters of Baja California, with moderate NW winds further offshore. NW winds should remain moderate or weaker through Fri night until the ridge strengthens slightly and freshens the winds Sat through Sun. No significant gap wind events are expected in the Gulf of Tehuantepec, although nocturnal northerly drainage flow to around 20 kt is expected there each night. These fresh winds combined with long period southerly swell will support seas to 8 ft through Sat morning until the southerly swell decays. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough should remain near 10N during the next few days. Easterly winds N of the trough will be moderate or weaker, while southwesterly winds S of the trough will also be moderate breeze or weaker. The exception will be offshore of the Gulf of Papagayo where winds will pulse to moderate to fresh each night. Long-period SW swell originating S of the equator is also impacting the Central America, Colombia, and Ecuador offshore zones, producing seas of 5 to 8 ft. These swell will gradually be diminishing during the next couple of days. REMAINDER OF THE AREA... Please see the Special Features section for information on Tropical Storm Lane. A surface trough is found in the far W central waters along 140W from 12N to 20N. No associated deep convection is present, however an area of fresh to strong winds and seas of 8 to 9 ft were recently captured by scatterometer and altimeter passes within an area bounded by 21N138W to 19N137W to 19N140W to 22N140W to 21N138W. This trough will shift W of 140W later this evening. Otherwise, ridging will continue to extend from NW to SE across the waters N of the convergence zone for the next several days. Mainly moderate trades and seas of 4 to 7 ft in mixed swell will prevail. $$ Lewitsky