000 AXPZ20 KNHC 090907 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Dec 9 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 0800 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pres 1010 mb near 10N74W to 05N81W to 04.5N90W. The ITCZ continues from 05N93W to 07.5N103W to 07N126W to 09.5N132W. Scattered moderate isolated strong convection is from 06.5N to 11.5N between 97W and 117W. Scattered moderate to strong convection is from 04.5N to 10N between 119W and 138W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gentle to moderate NW to N winds prevail across most of the offshore waters of Baja California tonight, north of Cabo San Lazaro, while light to gentle winds prevail southward to 20N. High pressure centered NW of the area has begun to build modestly into the northern waters tonight, and has begun a modest increase in winds across the area. Seas across the Baja waters remain 5-8 ft in NW swell, except 9 ft across the far outer waters, and are expected to begin to slowly subside Mon evening through Tue. Inside the Gulf of California, recent scatterometer data light and variable winds across most of the basin, with seas 3 ft or less. Winds are expected to shift northerly and increase modestly Mon evening and night, increasing to 15-20 kt across southern portions. Fresh northerly flow is then expected to prevail across central and southern sections of the Gulf through Wed morning with seas building to 4-6 ft. 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 will offshore. N gap winds continue to gradually diminish across the Gulf of Tehuantepec tonight, and will gradually diminish to less than 20 kt by Mon morning. The high pressure building across the Baja offshore waters tonight will build very weakly across the waters south of Cabo Corrientes Mon night through Tue to produce generally NW to N winds of 10-15 kt across most of the remaining Mexican waters through Wed. Looking ahead, another gale force gap wind event is expected to affect the Gulf of Tehuantepec Wed through Thu as a strong cold front crosses the Gulf of Mexico. Winds over Tehuantepec will quickly blast to gale force during the morning and could reach near 45 kt Wed afternoon through evening. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... NE to E winds less than 15 kt generally prevail across the offshore waters N of 10N and W of the Papagayo region, but are expected to increase to 10-15 kt Mon. Fresh to strong NE to E winds across and downstream of the Papagayo region will pulse to around 25 kt tonight and Mon night, and then to around 20 kt each night through Thu, with seas peaking between 8 and 9 ft downstream of the Gulf each morning. Elsewhere, gentle to moderate S to SW monsoon flow will persist across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador during the next several days. REMAINDER OF THE AREA... A 1024 mb high pressure center is located near 32N129W tonight and is building modestly south and southeastward into the sub- tropics. Recent scatterometer data showed NE to E tradewinds of 12-20 kt generally prevailing across the waters S of 25N and W of 120W. This high pressure will shift slightly S through Tue and induce a freshening tradewind flow across the region S of 22N to the ITCZ and W of 110W. NW swell propagating across the Baja offshore waters is also moving into this area tonight to produce seas of 9-11 ft. This swell will continue to gradually fade through Tue, however the increasing tradewinds will keep seas around 8 ft through midweek. A cold front will approach the NW portion of the discussion area Mon but stall before entering the regional waters. This front will however introduce new NW swell into the NW waters through the middle of next week. This swell will combine with the fresh to strong tradewinds S of 20N Wed night through Thu night to increase seas to 10-12 ft or higher. $$ Stripling