000 AXPZ20 KNHC 160310 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0110 UTC Sat Dec 16 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A cold front moving is moving southward across the western Gulf of Mexico. The prefrontal trough is just east of the Isthmus of Tehuantepec, which has helped funnel winds through the Chivela pass into the Gulf of Tehuantepec. Winds have increased to near gale force over the Gulf of Tehuantepec. The cold front will reach the Isthmus of Tehuantepec later tonight. Cool and dense air will funnel through the Chivela pass will further increase winds to gale force. The front will weaken Saturday, which will diminish winds funneling across the Gulf of Tehuantepec. This will keep this gale force gap wind event brief as winds are expected to diminish below gale force by Sat afternoon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N83W to 07N91W. The ITCZ continues from 07N91W to 06N100W to 11N130W to 10N140W. No significant convection is observed near the ITCZ, but scattered moderate convection is noted from 14N to 18N between 104W and 114W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: A cold front will move into the northern Gulf Sat, before stalling and dissipating over the central Gulf Sun. Winds over the northern Gulf will shift SW early Sat ahead of the front, as associated low pressure deepens over the lower Colorado River basin. The main issue by Sat night will be the possibility of strong W to NW winds over the northern Gulf as the low pressure shifts eastward into the Sonora Desert. While the fetch across the northern Gulf will be to limited to develop large seas, mariners should be aware of the possibility of sudden strong winds through low lying areas of Baja California Norte through early Sun. Winds diminish through early next week after the low pressure dissipates. A cold front will move through the waters off Baja California Norte through early Sat followed by strong NW winds and seas building to 8 to 12 ft by late Sat. Seas of 8 to 10 ft will cover most of the waters beyond 60 nm of the Baja coast through early next week in NW swell. Elsewhere gentle to moderate winds and 3 to 5 ft will persist along the coast of Mexico outside of the Gulf of Tehuantepec through mid week. Please see Special Features section for more information on the latest Gulf of Tehuantepec gale warning. Another gale force gap wind event is possible over the Gulf of Tehuantepec on Wednesday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Winds are expected to strengthen across the Gulf of Papagayo Sat night. Fresh N winds will funnel into the Gulf of Panama through late this morning. REMAINDER OF THE AREA... Fresh to strong tradewinds prevail from 15N to 21N west of 135W. Moderate to fresh winds prevails elsewhere over the forecast waters north of the ITCZ to 20N and west of 120W. Seas associated with a fresh pulse of NW swell are reaching near 14 ft in the area of strong trades W of 135W. Seas will slowly subside as the swell propagates southeast the next few days. A cold front will move into the far northern waters Saturday. This will usher in another set of northerly swell into the area. $$ AL