630 AXPZ20 KNHC 081511 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Apr 8 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 1200 UTC surface analysis and satellite imagery through 1430 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 10N86W to 05N100W. The ITCZ begins near 05N100W to 05N120W to 03N130W to 03N140W. Scattered moderate and isolated strong convection is from 05N to 07N between 90W and 93W and also between 95W and 99W. Similar convection is within 180 nm NW of a line from 09N112W to 07N120W to 05N125W to 05N131W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad high pressure ridge extends southeastward across the Baja California offshore waters to just beyond the Revillagigedo Islands near 19N107W. The pressure gradient between this ridge and lower pressure over inland Mexico is producing moderate to fresh northerly winds across the Baja California waters based on earlier scatterometer data and more recent ship observations. Large, long period NW swell moving through the regional waters has reach the Revillagigedo Islands and is producing 8-11 ft seas over the offshore waters north of Cabo San Lazaro, and 6-9 ft seas southward to 20N. This swell will continue producing dangerous surf conditions along the Baja California coast and through tonight. The swell will gradually build across the coasts of central Mexico from Las Tres Marias to Puerto Angel this afternoon through Wed, with peak seas of 6-8 ft. Looking ahead, winds are expected to strengthen to 20-25 kt over the offshore waters north of Cabo San Lazaro Tue through Wed as strong high pressure builds north of the region. Seas will build to 12-15 ft over the waters north of Punta Eugenia on Tue night in mixed swell. Wind speeds will gradually diminish by late week but remain fresh north of Cabo San Lazaro through Fri. Gulf of California: Moderate to fresh NW winds continue over the central and south portions of the Gulf of California this morning with gentle to moderate breezes north portions. Winds will diminish to gentle speeds by Tue as the pressure gradient weakens. Fresh to strong NW winds will develop across the northern and central Gulf late Tue night through Wed night as strong high pressure builds into the region, and a cold frontal system sweeps across the region. Winds 25-30 kt may briefly spill into far north portions of the Gulf Tue evening and night and then spread southward through Wed. Seas will build to 8 ft in the north Gulf briefly Tue night, and build to 6-8 ft across central portions Wed afternoon through night, then subside late in the week as the pressure gradient relaxes. Gulf of Tehuantepec: Gentle S to SW winds are expected across the Tehuantepec region through this evening. The next gap wind event in the Gulf of Tehuantepec is expected late tonight through early Wed as strong N winds funnel through the Chivela Pass and across the Gulf. These gap winds are expected to remain well below gale force. Gentle to moderate breezes return mid to late week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Light to gentle winds will prevail through Fri night. Gulf of Panama: Light to gentle breezes will prevail across the Gulf of Panama region this week. Seas will build to 5-7 ft by midweek as long period SW swell propagates into the area. Elsewhere, light to gentle winds will persist through the week. Wave heights between Ecuador and the Galapagos Islands will build to 5-7 ft beginning tonight as cross equatorial, long period SW swell moves into the region. SW swell will continue impacting the southern waters through the end of the week. REMAINDER OF THE AREA... Large, long period NW swell continues to propagate through the regional waters this morning, and has moved into the deep tropical Pacific waters. The swell will cover most of the waters west of 105W by Tue with seas ranging from 8-11 ft. Further S, cross equatorial SW swell is producing a small area of 8 ft seas south of 01S near 100W. A cold front has just moved SE into the far NW portion of the forecast area. High pressure at 1025 mb near 30N130W extends a ridge SE to near 17N120W. Mainly moderate to locally fresh trades cover the waters ahead of the front and N of the ITCZ under the ridge. Strong high pressure building in the wake of this front will support a tightening pressure gradient across the waters Tue through Thu night. This will result in a large area of fresh to strong N to NE winds across much of the region north of 18N through midweek. Northerly winds could approach 30 kt just beyond the Baja California Norte offshore waters Tue night. Seas will build to 12-15 ft across this region Tue night and persist into Wed night as NW swell mixes with S swell and NE wind waves. Expect wind speeds to diminish Fri and Fri night as high pressure weakens and moves westward, finally allowing the pressure gradient to relax. Recent altimeter data indicated seas of 8-11 ft in this region. $$ Lewitsky