000 AXPZ20 KNHC 032120 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu May 3 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N78W to 06N81W to 08N88W to 07N97W to 08N105W. The ITCZ continues westward from 08N105W to 10N117W to 08N130W to 07N140W. A cluster of moderate to strong convection is from 04N to 07N E of 80W to the coast of Colombia. Similar convection is from 05N to 08N between 82W and 85W. Scattered moderate to isolated strong convection can be found within about 150 nm S of trough between 88W and 95W, from 05N to 08N between 108W and 115W, from 10N to 13N between 107W and 111W, and within about 180-210 nm N of ITCZ axis between 120W and 128W. Scattered moderate to isolated strong convection is also noted in the Tehuantepec region. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure of 1028 mb located north of the area near 34N130W extends a ridge SE across the waters west of Baja California to near the Revillagigedo Islands. This system is forecast to reach the northern forecast waters in about 48 hours. Moderate to locally fresh NW winds are expected west of the Baja peninsula through Sunday, with 5-6 ft seas. Gulf of California: A brief surge of fresh NW winds is forecast along the coast of Sinaloa, Mexico from 22N-25N, and within about 45 nm offshore Cabo Corrientes Fri night as the pressure gradient tightens between low pressure over north-central Mexico and the aforementioned ridge W of Baja California. Moderate to locally fresh NW winds are expected elsewhere. Gulf of Tehuantepec: The next gap wind event in the Tehuantepec region is forecast to begin Saturday night, with very strong to minimal gale conditions possible Sun night, and then again Mon night. This will be associated with a building high pressure in the western Gulf of Mexico. Seas are forecast to build to near 12 ft with the strongest winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh NE winds are expected tonight and Fri. Gulf of Panama:Gentle to moderate SW to W flow is expected Fri and Fri night. Mainly light to gentle winds are forecast the remainder of the forecast period. Elsewhere, light to gentle winds will prevail N of the trough axis, while gentle to moderate south to southwest winds are expected S of the trough. Seas will be in the 4 to 6 ft range. REMAINDER OF THE AREA... High pressure of 1028 mb located north of the area near 34N130W extends a ridge across the forecast waters N of 15N W of 110W. The pressure gradient between this ridge and lower pressures associated with the ITCZ is supporting an area of fresh northeast trades from 10N to 15N W of 120W based on a pair of ASCAT passes. Seas of 6-8 ft are noted within this area of winds per altimeter data. A subtropical jet stream transporting deep layer moisture from the tropics northeastward into south-central Mexico is expected to persist through Friday. A frontal boundary will remain stationary near 30N140W over the next 48 hours, then move W of area, and merge with a new cold front approaching from the W. The new cold front will reach the far NW corner of the forecast region early on Mon, extend from 30N136W to 26N140W by Mon afternoon, and from 30N134W to 24N140W by Mon night. A new set of long period NW swell will follow the front, building seas to 14 or 15 ft near 30N140W by Mon night. $$ GR