000 AXPZ20 KNHC 080945 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Dec 08 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A light to moderate n breeze expected through mid afternoon today, then the n flow will increase to a strong breeze late this afternoon, and then further increase to minimal gale force during the overnight hours tonight with seas building to 12 ft downstream of the gulf near 15N95W at sunrise on Fri. The gradient will continue to tighten on Fri with 30 to 40 kt conditions expected late Fri with seas building to about 18 ft near 14.5N95.5W at sunset on Fri. The gale conditions will persist through sunrise on Sun. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends sw off the n coast of Costa Rica at 10N85W to 08N100W, then turns nw 09N110W, then sw to 09N115W where scatterometer winds indicate a transition to an ITCZ which continues w to beyond 08N140W. Isolated moderate to strong convection is noted from 04N to 08N e of 83W. Scattered moderate isolated strong convection is observed within 150 nm either side of a line from 08N97W to 12N109W to 11N126W to 08N134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Moderate to fresh nw flow is currently spreading s across the central gulf waters, and will dominate the entire gulf by late morning. This nw flow will increase to a strong breeze across the central gulf waters this afternoon, and spread s across the southern half this evening. The pressure gradient will relax Fri, with fresh nw flow expected across the southern gulf from Fri night into early Sat. A ridge extending from 23N116W to 14N94W will shift sw this afternoon. Gentle anticyclonic flow around the ridge this morning will become moderate to fresh breeze this afternoon w of the Baja Peninsula, and further increase to a strong nw breeze n of 28N within about 60 nm of the coast on Fri and Sat, with seas building to 8 ft across the waters n of 30N late in the weekend. Gulf of Tehuantepec: See special features. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to locally fresh nocturnal ene winds are expected at sunrise this morning. A strong gap event with seas to 8 ft is expected tonight, Fri and on Sat nights with a brief event on Sun night. Mostly light to gentle northerly winds, and combined seas of 2 to 4 ft, are occurring elsewhere n of the monsoon trough which is meandering e to w along about 10N. Light to moderate sw flow is observed from 05N to 10N where combined seas of 3 to 5 ft in long-period sw swell are expected this week. Moderate to fresh southerly flow expected s of 05N for the next several days with combined seas of 3 to 5 ft in sw swell. REMAINDER OF THE AREA... A 1022 mb surface high is analyzed near 30N125W with a ridge extending se to near 14N94W. This high will block the eastward advance of a cold front, causing it to stall from 32N137W to 31N140W today, and then further weaken as it drifts w on Thu night. Gentle to moderate nw to n flow is expected ne of the ridge for a couple of days. Moderate to fresh ne trades are forecast s of the ridge, seas building to 5 to 8 ft on Fri. $$ Nelson