000 AXPZ20 KNHC 151605 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1506 UTC Tue Jan 15 2019 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 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure over the Gulf of Mexico continues to funnel winds through the Chivela Pass and into the Gulf of Tehuantepec. These northerly winds are likely at minimum gale currently, though no observations have been present over the last few hours. Ship VRMA2 reported 25 kt NNW winds a couple hours ago about 180 nm south of Salina Cruz, consistent with gales closer to the coast. The gale should continue for about another 24 hours before diminishing slightly as the high pressure center over the U.S. Gulf Coast shifts eastward. The winds will drop below strong breeze by late Friday. Peak seas are around 14 ft currently and these will gradually dimish over the next few days. For more information, see the East Pacific High Seas Forecast under WMO/AWIPS headers FZNT02 KNHC/HSFEP2. Looking ahead, a powerful storm-force gap wind event is possible beginning on Sunday. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from 06N78W to 05N84W. The ITCZ extends from 05N84W to 05N98W with a break for a 1010 mb low at 05N102W and from 04N105W to beyond 04N140W. No significant deep convection is observed along the ITCZ. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Winds west of Baja California are light and variable and will remain below strong breeze through Friday morning. A developing storm over the U.S. Great Basin will help to tighten the pressure gradient and force strong breeze NW to N winds Friday and Saturday. NW swell of 8 to 11 ft are currently impacting these waters, which will gradually weaken through Thursday night. Reinforcing NW swell up to 15 ft will arrive starting early Friday and gradually diminish through Sunday. Gulf of California: Gentle to moderate NW winds will persist in the Gulf through early Saturday. These will build to NW strong breeze on Saturday and Sunday due to the developing storm system over the U.S. Great Basin. Wind wave could reach 8 ft on the weekend. Gulf of Tehuantepec: See discussion above for on-going Gale Warning and potential for Storm Warning on Sunday. Substantial high cloudiness with isolated showers are being advected across the water south of Baja California and into western Mexico ahead of a mid to upper- level trough along 122W. These should gradually diminish over the next couple of days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: NE strong breeze conditions are occurring in the Gulf due to a moderate pressure gradient over the western Caribbean and Central America. The strongest winds and areal coverage will be greater late night and early morning hours as nocturnal drainage augments the winds. Peak seas will reach about 9 ft. These conditions will continue through Saturday before briefly weakening on Sunday. Gulf of Panama: Scatterometer observations show NE strong breeze conditions in the Gulf this morning. The strongest winds and areal coverage will be greater late night and early morning hours as nocturnal drainage augments the winds. Peak seas will reach about 8 ft. These conditions will continue through Friday before weakening on Saturday and Sunday. REMAINDER OF THE AREA... An overnight scatterometer pass showed SW strong breeze conditions north of 28N between 123W and 130W. These will gradually weaken and pull northward. Late tonight renewed SW strong breeze ahead of the next cold front will reach our northwestern corner at 30N140W. The front will not progress far south into the area and W to NW winds behind the front should remain at fresh breeze or weaker conditions. Despite the relatively quiescent winds, long-period NW swell of at least 8 ft covers most of the area west of 110W. An altimeter pass this morning showed peak seas of 15 ft near 30N127W. These will gradually weaken through Thursday night. Reinforcing NW swell up to 15 ft will arrive starting early Friday and gradually diminish through Sunday. Farther to the southeast, a weak 1010 mb low is centered at 05N102W with scattered moderate convection within 120 nm in the eastern semicircle. Fresh to strong east winds are noted on the northern periphery of the low. A concurrent altimeter pass showed seas to 9 ft in the area of strong winds. This feature formed at the base of a negatively tilted mid/upper trough reaching into the deep tropics. The trough will continue to move west, reaching 120W by Fri. Winds and seas will diminish thereafter as the trough moves west of its upper support and weakens. In addition to the trough, the area from 04N to 15N between 95W and 110W will also see combined seas of 8 to 12 ft in a mix of long period NW swell and shorter period NE and E swell emerging out of the gap wind areas. $$ Landsea