000 AXPZ20 KNHC 281511 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1511 UTC Fri Oct 28 2016 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...a high pres ridge across eastern Mexico combined with lower pressures to the south of the Gulf of Tehuantepec near the monsoon trough, continues to produce a tight pressure gradient across the area. As a result, strong northerly winds will continue to pulse to minimal gale force through early Saturday. The gradient is forecast to weaken slightly thereafter, allowing for winds to remain below gale force through early next week. Seas will occasionally build to 12 to 14 ft during the strongest winds. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N74W to 08N103W to low pressure near 10N1140W to 10N121W. The intertropical convergence zone axis extends from low pressure near 12.5N134W to 10N140W. Scattered moderate convection is within 90 nm in the northwest semicircle of the low near 12.5N134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features section for details on a persistent Gulf of Tehuantepec gap event. Gentle to moderate NW winds prevail across the waters offshore of the Baja California peninsula. Winds will slowly diminish this weekend, as a dying cold front moves E and the pres gradient weakens. Combined seas of 5 to 7 ft with northwest swell will subside to 4 to 5 ft this weekend, then will build to 6 to 9 ft by Sunday as another cold front and a new set of north swell moves across the northern waters. The front will gradually dissipate as it approaches the area by early next week, with swells decaying Tuesday. In the Gulf of California, light and variable winds are expected today as an elongated northwest to southeast trough lingers across the gulf. Low pressure is forecast to develop in the far northern Gulf of California by early Saturday. Winds on the southeast side of the low are forecast to pulse to moderate to fresh through early next week. Seas will be 2 ft or less across the northern gulf through the weekend, building to 4 to 7 ft as the winds increase, with 2 to 4 ft seas expected over the southern half through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate west to northwest winds will prevail north of the monsoon trough, except moderate offshore winds will occur with nocturnal drainage flow Saturday night through early next week. Moderate southwest winds south of the monsoon trough will increase to moderate to fresh this weekend through early next week. Combined seas of 4 to 6 ft, will subside to 3 to 5 ft this weekend, building early next week to 5 to 7 ft. REMAINDER OF THE AREA... Low pressure, which is the remnant circulation of tropical cyclone Seymour, is located near 23N122.5W at 1007 mb. A small area of scattered moderate convection is located in the northeast quadrant between 60 nm and 240 nm. Lingering seas of 8 to 14 ft will quickly subside to less than 8 ft by early Saturday as the circulation continues to spin down, with a remnant trough expected by early Sunday. A dissipating cold front extends from 30N125W to 24N132W, with a pre-frontal trough north of 26N within 75 nm east of the front. Associated winds on either side of the front are 20 kt or less, however, mixed southeast and northwest swells of 8 to 11 ft are found across the northwest portion of the discussion waters behind the front. The front will dissipate by early Saturday as a new cold front quickly moves in from northwest of 30N140W. This next front will usher in a reinforcing set of northwest swells with seas building to up to 12 to 15 ft along 30N by early Sunday. The front will weaken as it translates to the east-southeast. Model guidance shows another front with an even more impressive set of northwest swell arriving by the middle of next week. Otherwise, trades south of 20N are mainly moderate, but will increase locally to fresh across the west central waters Sunday into early next week, as high pressure ridging builds in behind the next front, while a trough of low pressure along the ITCZ moves toward 140W. $$ LEWITSKY