000 AXPZ20 KNHC 100948 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Dec 10 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 0600 UTC surface analysis and satellite imagery through 0845 UTC. ...SPECIAL FEATURES... The next gale force gap wind event expected across the Gulf of Tehuantepec is expected to commence Wed morning and continue through around midday on Thu, as a strong cold front crosses the Gulf of Mexico. Winds over Tehuantepec will abruptly increase to gale force during the morning and could peak near 45 kt Wed afternoon or evening. Expect peak seas late Wed afternoon and evening to 16-17 ft downstream of the Gulf. Strong winds Thu evening will taper to fresh by Fri evening. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N74W to 05.5N94W to 08.5N109W to 07.5N124W. The ITCZ continues from 08N125W to beyond 09N140W. Scattered moderate to strong convection is noted from 06N to 13N between 100W and 125W. Scattered strong convection is from 07N to 10.5N west of between 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh NW to N winds prevail across most of the offshore waters of Baja California tonight. A 1024 mb high pressure center is located near 32N128W and will generally remain in place through Thu afternoon. Offshore seas are running 7-8 ft tonight in mixed NW swell. Expect winds and seas to diminish slightly Tue through before new NW swell moves into the region Wed night through Thu Inside the Gulf of California, fresh to locally strong NW winds will prevail across central and south portions of the Gulf tonight through Wed morning before diminishing slightly Wed and Thu. Peak seas to around 6 ft are expected across central sections during this time. Looking ahead, strong high pressure behind a new cold front moving across southern California will build across the region this weekend, bringing strong NW winds by Sat night and a significant NW swell into the area starting Fri afternoon. This event could persist into early next week. Elsewhere across the Mexican offshore waters, recent scatterometer data showed NW to W winds around 10 kt from Cabo Corrientes to Puerto Angel, becoming light and variable well offshore. The high pressure building across the Baja offshore waters tonight will build very weakly across the waters south of Cabo Corrientes tonight through Tue and generate generally NW to N winds of 10 to 15 kt across most of the remaining Mexican waters through Wed. Light and variable winds across the Gulf of Tehuantepec will prevail tonight through Tue night before the strong cold front moves across the western Gulf of Mexico. Winds across Tehuantepec will quickly blast offshore beginning around sunrise Wed, then quickly increase to gales. See the special section above for more details on this upcoming gale event. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh NE winds will pulse to strong across and downstream of the Gulf of Papagayo each night through Fri. The strongest and longest lived of these pulses will occur Wed night through Thu, with downstream seas building to 8 ft Thu morning. Elsewhere, gentle to moderate S to SW monsoon flow will persist across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador through Fri night. Moderate to locally fresh northerly winds are expected briefly across the Gulf of Panama Thu afternoon through evening. REMAINDER OF THE AREA... A 1024 mb high pressure center is located near 32N127W is slowly building SSE into the subtropics. Overnight scatterometer data generally showed NE to E tradewinds of 15 to 20 kt across the waters S of 24N and W of 115W. This high pressure will shift slightly S through Tue night and induce a freshening trade wind flow across the region S of 22N to the ITCZ and W of 110W. NW swell propagating across the Baja offshore waters will also move into this area overnight to produce seas 8-10 ft. The NW swell will continue to gradually decay through Tue night. However, increasing trade winds on the S side of the building high will compensate and keep seas around 8 ft in this area through mid week. A cold front has stalled across the NW corner of the discussion area near 30N140W. A much stronger frontal system to the NW of this front will also approach the NW corner of the area and stall Thu. Large NW swell will move out ahead of this next front and propagate into the regional waters beginning early Wed, and build through Fri. Seas are expected to build to 12-14 ft Thu night into Fri morning across far NW portions of the area. This swell will combine with wind waves generated by the fresh to strong trade winds S of 20N Wed night through Thu night to cause seas to build to between 10 and 13 ft by Fri night. $$ Stripling