000 AXPZ20 KNHC 150917 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 917 UTC Fri May 15 2020 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 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N86W to 08N105W to 1011 mb low pressure near 10N116W to 1011 mb low pressure near 07N125W. the intertropical convergence zone continues from 07N125W to beyond 06N140W. Scattered moderate convection is evident from 08N to 10N between 93W and 96W, and from 06N to 10N between 106W and 112W. Scattered moderate to strong convection is observed from 05N to 10N between 115W and 125W, and from 04N to 07N between 135W and 138W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends from a 1023 mb high pressure centered near 30N130W southeastward through the Revillagigedo Islands. Recent scatterometer and ship observations indicate fresh to strong NW winds off Baja California north of Punta Eugenia as the pressure gradient tightens between the high and lower pressure farther east. A concurrent altimeter pass indicated seas of 5 to 8 ft. Generally gentle to moderate winds are noted elsewhere with 4 to 6 ft seas in open waters in primarily SW swell. No significant shower or thunderstorm activity is noted in Mexican offshore waters. Haze and areas of smoke, mostly light, from agricultural fires in Mexico is present near the coast from Chiapas to Michoacan. For the forecast, the winds off Baja California will diminish starting Sat as the high pressure dissipates ahead of a weak cold front. Looking ahead, the front will weaken and dissipate through Mon as it approaches Baja California Norte. High pressure building in the wake of the trough will support fresh to strong winds again off Baja California by late Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Haze and areas of smoke, mostly light, from agricultural fires in northern Central America is present near the coast off Guatemala. A few showers and thunderstorms are active along the monsoon trough, beyond 200 nm off the coast from northwest Nicaragua to southern Guatemala. Gentle to moderate winds will persist through early next week. A new set of long- period southwest swell will reach the coast of Central America by tonight, before starting to subside by early next week. REMAINDER OF THE AREA... A 1023 mb high center is analyzed near 30N130W. Light to gentle winds are near this high center. A pair of 1011 mb surface lows are noted along the monsoon trough near 116W and 125W. Strong convection is noted near these low. A recent scatterometer pass indicate fresh winds on the north side of this low pressure. A concurrent altimeter pass showed seas of 8 ft near the low, likely with a component of southerly swell. Southerly swell in excess of 8 ft is noted mainly south of 10N between 95W and 125W. The high pressure area will diminish through Sun ahead of a cold front moving eastward across the waters north of 20N. Large, long-period NW swell will follow the front into the discussion area north of 20N and west of 120W from late Sat through late Mon. Looking ahead, the front will weaken as it shifts eastward early next week. High pressure will build in the wake of the front, possibly enhancing trade wind flow farther south into the tropics. The southerly swell is expected to subside. However slight enhancements to the trade winds near the areas of low pressure along the ITCZ or monsoon trough may allow for seas near the low pressure areas to reach 8 ft due to the trade wind flow and lingering southerly swell. $$ Christensen