000 AXPZ20 KNHC 191551 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1550 UTC Thu Jan 19 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough reaches from the coast of Colombia near 05N77W to 02N82W. The intertropical convergences zone extends from 02N85W to 05N100W to 03N110W to 07N125W to 05N140W. ...DISCUSSION... ...A Series of Strong Cold fronts will to affect much of the area... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... An upper trough that stretches from north-central Mexico southwestward to just south of the southern Baja California peninsula. A very well pronounced jet stream branch rounds the base of the trough, and is accompanied by strong southwest winds. Satellite water vapor imagery shows a persistent large moisture plume of mid and upper level clouds continuing to advect northeastward towards much of central Mexico with the strong jet stream winds. Available jet stream energy is combining with the deep moisture continues to produce scattered showers and possible isolated thunderstorms between Manzanillo and Cabo Corrientes. A stronger upper trough is noted on water vapor quickly sweeping southeastward from central California south- southwest to over the far northeast waters of the discussion area. This trough will overtake the first trough tonight into early Friday, and move eastward over northern and central Mexico through Saturday. Precipitable water and precipitation potential model guidance suggest that the moisture values will decrease Friday through Saturday along and offshore the central Mexican coast, however enough shallow moisture remaining will allow for isolated showers and thunderstorms exist over the these waters. The aforementioned strong upper trough supports a cold front reaching from southern California to 27N125W. Strong southwest winds will precede the front over starting tonight across the waters off Baja California Norte and the nothern Gulf of California. The winds will veer northwest and diminish thruogh Saturday across this region. Long period northwest swell of 8 to 12 ft will follow the front starting Friday across the offshore water off Baja California, with 8 ft swell reaching Soccorro Island by late Saturday. High pressure building behind the front will support strong notherly flow off the southern Gulf of California and off Cabo Corrientes by late Sunday as the leading edge of the 8 ft northwest swell reaches the coast near Manzanillo. Another front will push into to the waters off Baja California Norte by late Sunday with another round of strong northwest winds and 12 to 15 ft northwest swell. Farther south, a cold front moving through the western Gulf of Mexico will prompt strong gap winds through the Gulf of Tehuantepec by Sunday night, persisting into Monday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong gap winds through the Gulf of Papagayo will become moderate in speed early this afternoon, then become light to gentle variable winds by this evening before pulsing as fresh northeast winds late tonight and diminishing to moderate winds Friday morning, and becoming light to gentle winds clocking around from west- northwest to Friday afternoon to northwest Friday night and Saturday. light to gentle easterly winds will prevail elsewhere through Saturday. Seas will be generally 3-5 ft in the forecast waters. REMAINDER OF THE AREA... A 1024 mb high is now centered just west of the area at 27N145W. It extends a ridge eastward to the Baja peninsula. The gradient between the ridge and low pressure associated with the ITCZ is supporting an area of fresh to strong northeast trade winds from 08N to 11N west of 137W, with resultant seas in the 9-10 ft range. Fresh trades are elsewhere from 06N to 19N west of 137W, and from 10N to 14N between 122W-137W. Seas within these areas of fresh trades are in the 8-10 ft range due to mixed NE and NW swell. The ridge will be nudged southward over the next couple of days as the aforementioned cold fronts sweep across the waters north of 25N. This will allow the trades to decrease in coverage and shift westward through Saturday. Northwest swell with seas to 8-16 ft associated with a cold front moving eastward across the waters north of 25N today will be followed by a second front expected to sweep southeastward across the northern waters tonight through Friday night. Wave model guidance shows large northwest swell will propagate southeastward into the waters north of 20N behind the second front, with seas building quite large to 15-21 ft in the far northern waters east of 130W late Friday into Saturday. Yet another cold front will move into the far northwest waters on Saturday preceded and followed by strong winds. This front will lead another set of large northwest swell through the northwest waters, with latest wave model guidance indicating seas in the 14-21 ft range. $$ CHRISTENSEN