000 AXPZ20 KNHC 170947 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Nov 17 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 0945 UTC. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the coast of Costa Rica at 10N85W to 11N89W, then turns SW to 09N123W where scatterometer winds indicate a transition to an ITCZ which continues W to beyond 09N140W. Isolated moderate to strong convection is noted within 90 nm either side of a line from 07N80W to 08N101W. Scattered moderate isolated strong convection is noted within 120 nm either side of a line from 08N112W to 09N132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge will extend SE across the far offshore waters to the W of 100W through Sun. This will result in gentle to locally moderate N breezes across the waters W of Baja California through today. Expect moderate to locally fresh NW flow N of 25N within 90 nm of the Pacific coast of Baja beginning tonight, with these conditions spreading S across all waters W of Baja by late Sat and continuing into early Sun when the pressure gradient will begin to relax. Gulf of Tehuantepec: Pulses of strong to near gale force northerly drainage flow, with seas building to a max of 10 ft, are forecast through sunrise on Sat with winds becoming light and variable on Sat afternoon. Strong to near gale force conditions will resume late Sat night in the wake of a cold front in the Gulf of Mexico, and then increase to gale force on Sun morning through about sunrise on Mon morning, with seas building to a max of 16 ft downstream of the gulf waters near 14N95.5W on Sun night. Gulf of California: Light and variable winds expected through sunrise on Sat. Strong N winds will develop across the gulf waters N of 30N later on Sat morning in the wake of a cold front. Strong NW winds will shift S across the central gulf waters on Sat night through sunrise on Sun with seas building to 7 ft. Light NW winds forecast across the entire gulf waters on Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to locally fresh NE drainage winds are forecast during the overnight hours through the middle of next week with seas building to 5 ft downstream near 10N87W. Light and variable winds, and 3 to 5 ft seas, are expected elsewhere to the N of 09N, while moderate to locally fresh southerly winds, and 4 to 7 ft seas, are forecast S of 09N through the middle of next week. REMAINDER OF THE AREA... A 1011 mb surface low is centered near 30N134W with a weakening cold front extending SW to 20N140W. Long-period NW-N swell in the form of 7 to 9 ft seas currently w of the low and front will subside to less than 8 ft today. The low will shift slow E and wash out by late Sat night. Strong SE return flow will develop N of 22N W of 137W on Sat night, with these strong southerly winds spreading E across the waters N of 26N to the W of 130W on Mon night with seas of 7 to 11 ft, all ahead of a cold front reaching from 32N137W to 28N140W late Wed with seas building 12 to 16 ft W of the front. Gentle to moderate trade winds and 4 to 6 ft seas will persist farther S through Sat, with moderate to locally fresh anticyclonic flow on Sat night into Sun. $$ Nelson