Tropical Weather Discussion
Tropical Weather Discussion NWS National Hurricane Center Miami FL 402 UTC Fri Apr 27 2018 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N84W to 08N100W. The intertropical convergence zone continues from 08N100W to beyond 06N140W. Scattered moderate convection is from 03N to 08N between 85W and 95W and from 05N to 12N between 115W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate NW winds off the coast of Baja California will increase to fresh through the morning as ridging builds west of the area and a trough forms over the Colorado River valley through the northern Gulf of California. A recent altimeter pass showed seas to 8 ft between the Revillagigedo Islands and Cabo San Lazaro, likely with a component of NW swell. NW winds off Baja California Norte will increase late Fri through Sat night as an upper trough moves across the region allowing the surface low pressure to deepen. Seas will build north of Cabo San Lazaro with the increase winds, reaching 8 to 10 ft, but subside farther south. Winds and seas diminish through early next week as the trough shifts eastward and high pressure builds into the region. Pulses of strong westerly gap winds are possible over the northern Gulf of California as the trough shifts eastward late Sun into Tue. Farther south, fresh to strong northerly winds are possible in the Gulf of Tehuantepec this weekend, particularly during Sat morning as high pressure builds over the western Gulf of Mexico. Elsewhere, mainly light to gentle winds are expected through Sun with 4 to 6 ft seas. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh northeast nocturnal winds are expected in and downstream of the Gulf of Papagayo beginning Sun night. Gentle to moderate offshore flow will prevail elsewhere N of 09N, and light to gentle SW winds are expected S of 09N with seas of 4 to 6 ft. REMAINDER OF THE AREA... A surface trough, the remnants of a dissipated cold front, extends from 32N130W to 27N135W. A ridge is building behind this trough as the trough weakens, reaching from 1026 mb high pressure near 36N146W to the Revillagigedo Islands. Moderate to fresh northeast trade winds and 7-9 ft seas are observed across the tropical waters W of 115W between 08N and 20N, south of the subtropical ridge and north of the the ITCZ. These winds will increase to fresh to locally strong as the pressure increases north of this region into the upcoming weekend. This will also result in an increase of the areal coverage of seas of 8-9 ft. Winds and seas will decrease early next week as the high center shifts northward.