000 AXPZ20 KNHC 150855 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Dec 15 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 0745 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 07N90W to 06N103W. ITCZ continues from 06N105W to 08N124W to 10N140W. Scattered moderate convection is from 05N to 11N W of 136W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure building off the coast of California is supporting fresh to strong NW winds over the waters off Baja California Norte continuing through this evening as the high pressure weakens. Long period NW swell continues to propagate across the waters off Baja California with seas of 8 to 13 ft prevailing over the waters off Baja California Norte and seas to 10 ft across the waters N of the Revillagigedo Islands. Seas will start to subside late Mon, and fall below 8 ft Tue morning. A fresh set of NW swell will propagate into the waters off Baja California Norte Wed evening. High pressure building over the Great Basin north of the area will support fresh to strong NW winds across the Gulf of California late Mon through early Wed. Looking ahead in the Gulf of Tehuantepec, a strong cold front will move into the northwest Gulf of Mexico Mon night, shift southward across the western Gulf of Mexico, reaching the Bay of Campeche Tue. High pressure will build southward across the Sierra Madre Oriental in the wake of the front. The pressure gradient between this building high pressure, and the equatorial trough in the eastern north Pacific will usher in the next gale force gap wind event Tue night. This will be a strong gap wind event, with wind speeds possibly reaching minimal storm force, and seas building in excess of 20 ft on Wed. Gale conditions are forecast to prevail through Fri. 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, increasing to fresh to strong Wed, and continuing through Fri. 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... Latest scatterometer satellite data show persistent fresh to strong trade winds mainly from 10N to 18N W of 130W. This is in an area between a weak low pressure near the ITCZ, a surface trough along 138W and higher pressure over the subtropics north of the area. Concurrent altimeter data show seas of 8 to 11 ft north of roughly 01N and west of 120W, attributable to a component of long period NW swell, mixed with shorter period NE swell and wind waves in the area of fresh to strong trades. The high pressure north of the area will shift eastward today ahead of the next cold front to enter the NW waters on Mon evening. This will allow the trade winds to diminish slightly. The seas will subside as well as the current swell gradually decays. Looking ahead, the front will sweep southeast over the waters north of 15N through the middle of next week. Another round of large, long-period NW swell will accompany the front across most of this region. $$ Ramos