000 AXPZ20 KNHC 081451 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1451 UTC Thu Dec 8 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 1415 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A light to moderate northerly breeze is expected through the mid-afternoon, increasing to a strong breeze late this afternoon, and then further increase to minimal gale force during the overnight hours tonight. Seas will quickly build to 12 ft downstream of the gulf near 15N95W by sunrise Friday. The gradient will continue to tighten on Friday with winds increasing up to 45 kt Friday evening and night. Seas will build to around 20 ft by late Friday night into early Saturday. The gale conditions will persist through sunrise on Sunday, then will pulse to near gale force Sunday night. Another brief and weaker gale force wind event is possible Monday and Monday night. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N83W to 07N100W to 10N110W to 08N117W. The intertropical convergence zone axis extends from 08N117W to 09N125W to 07N140W. Scattered moderate convection is from 06N to 10N between 97W and 101W, and also from 07N to 10N between 108W and 111W. Scattered moderate and isolated strong convection is from 09N to 13N between 111W and 127W. Low pressure is south of the Gulf of Panama near 06N78W. Scattered moderate convection is within 180 nm in the southwest semicircle. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Moderate to fresh nw flow is currently spreading s across the gulf waters, increasing to fresh to strong across the central gulf waters this afternoon, then spreading south through the entrance to the gulf by this evening. The pressure gradient will relax Friday, with fresh nw flow expected across the southern gulf from Friday night into early Saturday. A ridge extending from 24N116W to 16N104W will shift southwest this afternoon. Gentle anticyclonic flow around the ridge this morning will become moderate to fresh breeze this afternoon west of the Baja Peninsula, and further increase occasionally to a strong northwest breeze north of 28N within about 60 nm of the coast on Friday and Saturday. Seas will build to around 8 ft across the waters north of 30N with the increasing winds. 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 offshore winds will surge to fresh to strong tonight, and will continue to pulse to fresh to strong mainly during the overnight hours this weekend. Seas will also build to around 8 ft. A strong trough of low pressure will move from the western Caribbean Sea into the Pacific waters late Sunday through Monday. Monday guidance indicates possible weak low pressure developing along this trough as it moves from zones PMZ113 to PMZ111 through early next week. Mostly light to gentle northerly winds, and combined seas of 2 to 4 ft, are occurring elsewhere n of the monsoon trough, which continues to meander along about 10N. Light to moderate southwest flow is observed from 05N to 10N, where combined seas of 3 to 5 ft in long period southwest swell are prevailing. Moderate to fresh southerly flow is expected south of 05N for the next several days, with combined seas of 3 to 5 ft. REMAINDER OF THE AREA... A 1022 mb surface high is analyzed near 29N124W with a ridge extending southeast from the high. The high will block the advancement of a cold front currently reaching to 32N140W, causing it to stall from 32N137W to 31N140W through the day, and then further weakening as it retreats back to the northwest tonight. Gentle to moderate northwest to north flow is expected to the northeast of the ridge for a couple of days. Moderate to fresh trades are forecast to the south-southwest of the ridge, locally to strong tonight. Combined seas are forecast to build to up to 8 ft just north of the ITCZ late tonight through the weekend. $$ LEWITSKY