074 AXPZ20 KNHC 140950 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Aug 14 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...TROPICAL WAVES... A well defined tropical wave is along 117W-119W with a 1011 mb surface low along the wave at 10.5N118W. This system is progressing W at 10-15 kt. Scattered moderate to strong convection is occurring in short bands within 210 nm across the NW semicircle of the low, while scattered moderate isolated strong convection is within 360 nm across the SW quadrant. Environmental conditions are conducive for slow development, and a tropical depression could form late this week while this disturbance moves westward. A tropical wave is analyzed along 130W-131W from 06N to 21N with a weak 1013 mb surface low analyzed near 17N129W. A mid level circulation is apparent along the northern end of tropical wave above the surface low. Convection with this wave has diminished during the past several hours, with scattered moderate isolated strong convection noted within 150 nm across the N semicircle of the low. This wave and associated low are forecast to reach cooler waters by this afternoon, which would limit further development chances. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N74.5W TO 10N97.5W TO low pres near 10.5N118W TO low pres near 17N129W. Scattered to locally numerous moderate to strong convection is noted from 02.5N to 11N E of 81.5W to Colombia and Panama. Scattered moderate to strong convection is observed from 05.5N to 13N between 81.5W and 111W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Evening observations along the Pacific coast of Baja California indicated fresh NW winds continuing along the coast and immediate waters from Isla Cedros to Cabo San Lazaro, where seas were 5-6 ft. However, winds have diminished slightly there early this morning and are expected to generally prevail today. A ridge extends SE into the area to near 16N109W and will maintain moderate NW wind flow across the Baja waters to Las Tres Marias through Tue. Late afternoon heating will allow for wind flow to become fresh late Tue afternoon and evening along the southern half of the peninsula again Tue. The ridge is expected to be reinforced late Tue with stronger high pressure across the NE Pacific reinforcing the modest ridge SE into the area, producing generally moderate NW wind flow through Fri. Light to gentle southerly winds are noted across the Gulf of California, and area expected to prevail for the next few days, occasionally pulsing to moderate to fresh over the northern Gulf mainly at night. Scattered showers and thunderstorms are active over the entrance of the Gulf of California from Mazatlan southward to Cabo Corrientes, resulting from a mid/upper level trough pivoting across northwest Mexico. This weather will gradually end by sunrise. Otherwise, little change is expected. Farther south, long period SW swell will move into the offshore waters between Puerto Angel and Baja California Sur Tue through Wed, with seas peaking at 7 to 10 ft Wed evening into Thu morning, and highest seas across the waters between Guatemala and Cabo Corrientes. This will produce very large and dangerous surf conditions along the coastlines and outer reefs with localized breaking waves 15-20 ft Wed through Thu morning. Looking ahead, fresh to strong gap winds are expected by Thu night in the Gulf of Tehuantepec. 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 is expected tonight through morning followed by fresh nocturnal easterly flow through Fri morning. Very active convection occurring along either side of the monsoon trough will shift westward tonight and Tue from Colombia and Panama to offshore of Guatemala and El Salvador. 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 has spread into the regional waters overnight and has raised offshore seas to 6 to 8 ft on either side of the Galapagos Islands. A stronger and larger pulse of SW swell will move into the regional waters Tue night. This next pulse of cross equatorial swell will raise seas to 7-9 ft Wed through early Thu before slowly subsiding through Fri, and produce large and dangerous surf conditions along the coasts and outer reefs. REMAINDER OF THE AREA... The remnant low of former tropical cyclone Kristy is centered near 23.5N137W and estimated at 1015 mb. Winds continue near 20 kt across the NW quadrant, with 6 to 8 ft seas within 150 nm. This low pres center has begun to accelerate tonight to 10-15 kt and will continue this movement over the next few days and slowly dissipate to a trough as it approaches 140W this evening. The remnant low of former tropical cyclone John is centered near 28N120W and estimated at 1015 mb is moving SE and will weaken to a trough late tonight. 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. $$ Stripling