000 AXPZ20 KNHC 311522 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1520 UTC Tue Dec 31 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 07N87W to 05N103W to 11N117W to 08N131W. The ITCZ continues from 08N131W to beyond 07N140W. Scattered moderate convection is noted within 90 nm of the monsoon trough east of 82W, from 03N to 08N between 86W and 92W, from 05N to 09N between 107W and 111W, and within 180 nm north of the ITCZ west of 131W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... An occluded 1010 mb low pressure system is centered offshore of Punta Eugenia near 28N117W. An associated cold front extends from 27N114W southwestward across the Baja California Sur waters, while a reinforcing cold front follows closely behind it. Overnight scatterometer data showed a large area of fresh to strong winds in the western semicircle of the low poleward of the secondary front. Elsewhere, fresh northerly winds are noted over the far northern Gulf of California. Strong northerly gap winds are likely occurring in the Gulf of Tehuantepec as an enhanced north- south pressure gradient persists across southern Mexico. The low pressure system and its cold front will track SE across the Baja peninsula through Wed night while weakening, with fresh to strong northerly winds and building seas expected behind the front. A set of large, very long period NW swell will propagate SE across the region Wed through Fri, producing dangerous surf conditions along the Pacific coast of Mexico. Strong northerly winds will persist over the Gulf of Tehuantepec through tonight, then diminish on Wed. Looking ahead, a strong cold front will move across the Gulf of Mexico late this week. There is good model support for gale force winds over and downstream of the Gulf of Tehuantepec beginning late Fri night through the weekend, with strong gales or even minimal storm force winds possible. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Recent GOES-16 satellite imagery and lightning data depict scattered moderate convection near the monsoon trough off the coast of Panama and Costa Rica. Winds remain less than 20 kt across much of the region, except for fresh gap winds in the Gulf of Papagayo. Fresh to occasionally strong NE to E winds will pulse over the Gulf of Papagayo region through Thu, then diminish by Fri. Very long period NW swell will move SE across the offshore waters Fri night through Sat night. A strong Papagayo gap wind event is likely Sat night as high pressure builds into the western Caribbean. Elsewhere, gentle to moderate S to SW flow will continue across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador through Sat. REMAINDER OF THE AREA... A strong high pressure ridge over the NW portion, anchored by a 1033 mb high near 34N140W, is supporting fresh to strong trades north of 09N and west of 130W based on overnight scatterometer data. Seas in this region are generally 9-13 ft in mixed NW swell and NE wind waves. A low pressure system offshore of the Baja peninsula is pushing two cold fronts across the northern waters. Strong winds prevail poleward of the fronts, with seas peaking around 16 ft near 29N126W and 8-12 ft seas behind the front west of 120W. Elsewhere, gentle to moderate winds persist across most of the region. Fresh to strong trades will prevail through Wed. A set of large, very long period NW swell will enter the NW portion today and propagate SE through the week. This will result in seas greater than 12 ft north of 10N and west of 130W persisting through Wed night. Wave heights will gradually subside by late week through the weekend. $$ Reinhart