000 AXPZ20 KNHC 240635 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Nov 24 2017 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURE... A gale warning remains in effect for Gulf of Tehuantepec. Minimal gale force winds are noted across the Gulf of Tehuantepec and downstream to near 14N96W with seas of 12-13 ft. The most recent scatterometer pass indicated that the fresh to strong N to NE winds extend farther south to near 12N97W. Winds are forecast to diminish below gale force by mid-day today, and to 20 kt or less late Sat morning. The NE swell generated by this gap wind event is mixing with long-period cross equatorial swell, with seas 8 ft or higher well downstream of the Gulf of Tehuantepec along 09N between 94W and 100W. Expect winds 20 kt or less and seas less than 8 ft only briefly on Sat afternoon. Strong N winds are forecast to resume again on Sat night, with gale conditions expected by mid-day Sun. Latest guidance is suggesting another 30 to 40 kt gap wind event on Sun night, with seas building to 15 or 16 ft. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 08N90W to 07N101W. The ITCZ continues from 07N101W to 11N117W to 10N130W to 09N135W to beyond 10N140W. Scattered moderate convection is occurring from 08N to 10N between 130W and 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features paragraph above for information on the Gulf of Tehuantepec Gale Warning. A modest high pressure ridge centered offshore of southern California has weakened considerably today and is yielding gentle and variable winds with seas of 2 to 4 ft across the offshore waters of Baja this morning and are expected to continue today. Seas will begin to build Fri afternoon in NW swell, and peak at 4 to 7 ft at 13 to 15 seconds across the waters W of Baja Fri night, then subsiding some on Sat into Sun. Long-period NW swell in the form of 7 to 9 ft seas will reach 30N120W on Sun night, and spread S across the waters W of Baja with 8 to 13 ft seas at 17 to 19 seconds forecast W of Baja Mon night and Tue. Gulf of California: Recent scatterometer passes indicated that winds have become light to locally moderate across the entire Gulf. This flow will continue through tonight. The pressure gradient will relax further, with light and variable winds expected Fri through Mon. Strong to near gale force NW flow is expected to develop N of 26N on Mon night through Tue night, with seas building to 10 to 11 ft across the long fetch waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Fonseca...Fresh NW winds forecast to begin around sunrise on Mon. Gulf of Papagayo: Fresh to locally strong NE nocturnal drainage flow forecast to begin tonight, with diurnally driven strong pulses through Tue. Seas of 8 ft or greater will propagate SW to near 08N92W on Tue. Light and variable winds, and 3 to 5 ft seas, are expected elsewhere through Sun night to the N of the monsoon trough which has been meandering between 09N and 11N. Moderate NE flow expected N of the Gulf of Papagayo early Mon. Moderate southerly winds, and 3 to 6 ft seas, are forecast S of the monsoon trough. REMAINDER OF THE AREA... A stationary front from 30N138.5W TO 28N140W will drift westward through Fri with a broad surface low developing along the front just W of the area tonight. The low will move NE of the area on Fri night with the front then moving SE to extend from 30N132W TO 22N137W by Sat evening. Scattered moderate, but weakening convection is observed well E of the front from 17N to 25N between 136W and 140W. Combined seas of 8 to 14 ft at 14 to 16 seconds is currently observed across the discussion waters W of a line from 30N126W TO 17N140W. This long period NW swell will propagate across the waters W of a line from 32N121W to 12N140W early Fri before beginning to subside and shrink in area to mainly S of 15N and W of 125W by late Sat. $$ GR