000 AXPZ20 KNHC 140232 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 231 UTC Sat Dec 14 2019 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 05N105W. A segment of the intertropical convergence zone continues from 05N105W to 09N110W. Another segment of the ITCZ reaches from 07N130W to beyond 08N140W. Scattered moderate isolated strong convection was noted from 10N to 12N between 94W and 97W. Scattered moderate convection was also noted from 13N to 15N between 117W and 119W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... In the Gulf of Tehuantepec, a weak pressure pattern north of the area is maintaining moderate to fresh gap winds into the Gulf of Tehuantepec. Winds will increase slightly overnight into early Sat morning due to a combination of weak high pressure building over the southwest Gulf of Mexico, and local overnight drainage flow. Winds will diminish as the high pressure shifts eastward through Sat, although pulses to 20 kt are possible Sat night and Sun night. Looking ahead, The next major cold front will move through southern Mexico by Tue. Early indications from various model data show near storm strength gap winds by mid week, with strong gap winds and building seas reaching as far as 360 nm downstream into open waters. Farther north, recent ship observations confirmed fresh winds off the coast of Cabo Corrientes, between high pressure over the central plateau over central Mexico and lower pressure off the Pacific coast of southern Mexico. These winds should diminish overnight as the high pressure weakens. The pressure gradient between a ridge anchored by a 1029 mb high near 30N134W and a trough across the Gulf of California is maintaining gentle to moderate northerly flow off the coast of Baja California, with moderate to fresh NW winds across the Gulf of California. A cold front will move into the waters off northern Baja California Norte early Sat. The front will weaken as it shifts across Baja California Norte and the northern Gulf of California through late Sat, just as a reinforcing front moves into the region. The second front will also weaken as it shifts into Baja California Sur and the central Gulf of California through Sun. High pressure building behind these fronts northwest of the region will support fresh to strong NW winds along the coast of Baja California Norte Sat into Sun, diminishing through late Sun as the high pressure shifts eastward. Meanwhile, long period NW swell in excess of 8 ft will continue through the offshore waters of Baja California and reach the Revillagigedo Islands by Sat night. High pressure building over the Great Basin north of the area will support fresh to strong NW winds across at least the northern Gulf of California by late Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh winds are expected across the Gulf of Papagayo through the forecast period. Elsewhere, gentle to moderate south to southwest monsoon flow will persist across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador through Sat night, while light to gentle flow is across the Gulf of Panama. REMAINDER OF THE AREA... The pressure gradient between a 1029 mb high pressure center located near 30N134W two areas of low pressure, centered near 13N122W and 11N132W is supporting fresh to strong trade winds across the waters from 07N and 20N and west of 115W. NW swell is propagating across the forecast waters, with seas in the 8 to 13 ft range north of 05N and west of 115W. The NW swell will continue across the forecast waters, with seas 8 ft or greater covering the waters north of 07N and west of 110W into early next week. Looking ahead, a fresh set of NW swell will move into the northwest waters early next week, with seas building in excess of 8 ft to as high as near 20 ft by midweek. $$ Christensen