000 AXPZ20 KNHC 231332 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1311 UTC Mon Dec 23 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 1300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Tight pressure gradient between high pressure centered near the eastern slopes of Mexico's Sierra Madre Oriental and low pressure of the monsoon trough in the eastern N Pacific is supporting gale force northerly gap winds in and near the Gulf of Tehuantepec, with seas to near 18 ft. As high pressure gradually weakens, this gradient will relax and winds will slowly veer and diminish, below gale force by late Tue. Swell generated from these ongoing gap winds continue to produce a large plume of 8 ft or greater seas that extends beyond 100W. Marine interests should take necessary action to avoid hazardous marine conditions over the affected waters. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers HSFEP2/FZPN03 KNHC or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N81W to 07N94W to 1010 mb low pressure near 07N103W to 06N106W. The ITCZ continues from 06N106W to 09N119W to 09N128W to 08N140W. Scattered moderate convection was noted from 06N to 08N between 90W and 95W, from 07N to 09N between 100W and 104W, and from 07N to 11N between 116W and 123W. Scattered moderate to isolated strong convection was noted from 07N to 11N W of 132W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details about the ongoing gale force gap winds across the Gulf of Tehuantepec. On Tue, a cold front will move through waters W of Baja California, increasing winds and seas. Expect fresh to strong W to NW winds and seas building to 9 ft. Another cold front is forecast to move across Baja California Norte into the northern Gulf of California on Thu bringing an an increase in winds and seas. A larger set of NW swell will follow the front, with seas building to 12 to 16 ft N of Punta Eugenia, and to 8 to 14 ft between Cabo San Lazaro and Punta Eugenia by Thu night. Fresh to strong NW winds will develop offshore of Cabo Corrientes by mid-week due to a locally tight pressure gradient between a ridge extending eastward to beyond the Revillagigedo Islands and lower pressures over north-central Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Seas generated by gales in the Tehuantepec region will continue to propagate across the offshore waters of Guatemala and El Salvador through Tue. Seas will start to subside to less than 8 ft by Tue night. Fresh to strong winds and building seas are expected across the Gulf of Papagayo and downwind to near 90W through the next several days, pulsing to near gale force during the overnight and early morning hours through at least Tue. Elsewhere, gentle to moderate south to southwest monsoon flow will persist across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador, while light to gentle flow will dominate across the Gulf of Panama. REMAINDER OF THE AREA... A cold front is located over the northern waters from near 31N117W to 19N125W. Behind the front long period NW swell is contributing to seas to as high as 14 ft. This front will weaken and dissipate as it moves east. High pressure is building in the wake of the front. This has tightened the pressure gradient and increased trades across the W central waters. The fresh to strong trades will continue through at least Wed. Another surge of fresh to strong NW is accompanying a cold front that is crossing S over 31N between 125W and 140W this morning. $$ KONARIK