230 AXPZ20 KNHC 132129 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2129 UTC Mon Aug 13 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. ...TROPICAL WAVES... A broad tropical wave is along 115W-116W with a 1011 mb surface low along the wave at 11N116W. This system is progressing W at 10-15 kt. Scattered moderate convection is observed from 06N to 16N between 115W and 120W. Environmental conditions are conducive for slow development, and a tropical depression could form late this week while the disturbance moves westward. A tropical wave is analyzed along 127W/128W from 06N to 20N. A mid level circulation is apparent along the tropical wave near 16N127W, and this may be starting to form at the surface. Scattered moderate convection is noted from 15N to 16N between 123W and 128W. While this system is showing some signs of organization, the low is forecast to reach cooler waters by tomorrow afternoon, which would limit further development chances. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 11N114W. The intertropical convergence zone extends from 14N130W to 10N140W. Scattered moderate to strong convection is noted within 120 nm south of the monsoon trough, mainly along the coastlines of Panama and Costa Rica. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Earlier ship observations along Pacific coast of Baja California indicate moderate to fresh NW winds funneling along the coast between Punta Eugenia and Cabo San Lazaro. These are the result of a locally tight pressure gradient between weak ridging just off the coast, and the weak 1015 mb remnant low of former tropical cyclone John west of the offshore area near 28N122W. Gentle to moderate breezes are noted elsewhere over open waters with 3 to 5 ft seas. The surface low will drift eastward toward Guadalupe Island and weaken to a trough later this evening before dissipating through Tue, allowing winds off Baja California to diminish. Farther south, long period SW swell will move into the offshore waters between Puerto Angel and Cabo Corrientes, with combined seas reaching 6 to 8 ft Tue into Thu, with highest seas south of the Gulf of Tehuantepec. Looking ahead, fresh to strong gap winds are expected by Thu night in the Gulf of Tehuantepec. Light to gentle southerly breezes are noted across the Gulf of California, occasionally pulsing to moderate to fresh over the northern Gulf mainly at night. A few showers and thunderstorms are active over the central Gulf of California resulting from a mid/upper level trough pivoting across northwest Mexico and local overnight drainage convergence. Little change is expected. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to locally strong E drainage flow expected tonight followed by fresh nocturnal easterly flow through Fri morning. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough which is meandering between 09N and 11N. Moderate to locally fresh southerly winds are forecast S of the monsoon trough through early next week. Long period S to SW swell will spread into the regional waters late Mon and raise offshore seas to 7 to 8 ft on either side of the Galapagos Islands, before a strong and larger pulse of SW moves into the regional waters Tue. This next pulse of cross equatorial swell will raise seas to 7-9 ft Wed through early Thu before slowly subsiding through Fri. REMAINDER OF THE AREA... The remnant low of former tropical cyclone Kristy is centered near 23.5N135.5W and estimated at 1015 mb. Winds have diminished to 20 to 25 kt, with 6 to 7 ft seas, within 90 nm over the NW quadrant. This low pres center has been moving slowly westward that past 24 hours, but is forecast to gradually accelerate to 10-15 kt over the next few days and slowly dissipate as it approaches 140W Tue evening with winds and seas diminishing accordingly. The remnant low of former tropical cyclone John is centered near 28N123W and estimated at 1014 mb is drifting NE and weakening to a trough today. Fresh NE winds of 15-20 kt are occurring within 210 nm over the NW semicircle tonight and will weaken as the low opens to an open trough. Long-period cross-equatorial southerly swell, in the form of 7 to 10 ft seas, will propagate N across the tropical waters S of 20N E of 120W Tue night through Thu, and then subside to less than 8 ft on Thu night. $$ Christensen