000 AXPZ20 KNHC 230842 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 618 UTC Fri Dec 23 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 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec: Winds to gale force into the Gulf of Tehuantepec will end later this morning as high pressure north of the area weakens and overnight drainage effects cease. Northerly winds of 20-30 kt are expected tonight into Saturday morning, once again with the aid of the nocturnal drainage flow. Winds will further diminish to 20-25 kt Saturday night into Sun morning. Marine guidance suggests that winds will increase to minimal gale force Monday night into Tue morning as a ridge builds again across the western Gulf of Mexico. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N84W to 05N94W. The intertropical convergence zone axis continues from 05N94W to 06N110W to 10N123W, then resumes west of a trough at 09N125W to beyond 08N140W. Scattered moderate convection is from 08N to 12N between 105W and 120W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front moving southward along the coast of California will sweep Baja California Norte and the northern Gulf of California through Sunday. Strong southwest to west winds will precede the front over the northern Gulf of California tonight through early Sunday. The fetch across the Gulf will be enough to support seas building to 9 ft by late Saturday night over portions of the northeast Gulf of California. Strong northwest winds will follow the front over offshore waters off Baja California Norte Saturday into Saturday night, with 8 to 13 ft seas. Related northwest swell in excess of 8 ft will propagate across the remainder of the offshore waters off the coast of the Baja California peninsula through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong gap winds pulsing through the Gulf of Papagayo this morning will diminish later this morning. The overall gradient is weakening north of the area, but will allow brief pulses to 20 kt over the next couple of nights. Elsewhere across the region, winds will remain 20 kt or less, with seas below 8 ft through early next week. Moderate Northerly winds are expected across the Gulf of Panama during the overnight and early morning hours. REMAINDER OF THE AREA... Long period northwest swell continues to impact much of the waters north of 07N and west of 110W. A cold front will sweep across the waters north of 25N and east of 130W late today through Saturday, followed by strong northwest winds and 8 to 12 ft seas. The winds and seas subside by late Sunday as the front shifts east of the area. High pressure building north of the area behind the front will support strong trade wind flow mainly from 07N to 21N and east of 130W tonight into early next week. Another cold front will move into the waters north of 25N west of 125W Sunday night through Monday, followed by strong northwest winds and 8 to 13 ft seas. Looking ahead, there remains some uncertainty among global models regarding the development of weak low pressure along this front by Monday. The main impact of this would be to tighten the gradient between the low pressure and the ridge to the northwest, increasing northerly winds and seas over the waters north of 25N and west of 125W. Models agree on this general pattern but differ as to the relative strength of the low and subsequent winds and seas. The official forecast follows more of consensus track for now. $$ CHRISTENSEN