622 AXPZ20 KNHC 140413 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...TROPICAL WAVES... A well defined tropical wave is along 116W-118W with a 1010 mb surface low along the wave at 11N116.5W. This system is progressing W at 10-15 kt. Scattered moderate isolated strong convection is occurring in short bands from 07.5N to 16N between 114W and 121W, surrounding the surface low. Environmental conditions are conducive for slow development, and a tropical depression could form late this week while the disturbance moves west northwestward. A tropical wave is analyzed along 128W-130W from 06N to 21N with a weak ill defined 1011 mb surface low analyzed near 16.5N128W. A mid level circulation is apparent along the northern end of tropical wave above the surface low, and this may act to improve the circulation at the surface. Scattered moderate convection is noted from 14.5N to 19N between 126W and 131W. 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 09.5N73.5W TO 10N96W TO low pres near 11N116.5W TO low pres near 16.5N128W TO 11N135W. Scattered to locally numerous moderate to strong convection is noted from 05N to 11N E of 91W to Colombia and Panama. Scattered moderate to strong convection is observed from 06.5N to 12N between 91W and 110W, and within 60 nm either side of the trough between 130W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Evening observations along the Pacific coast of Baja California indicate fresh NW winds continue along the coast and immediate waters from Isla Cedros to Cabo San Lazaro, where seas are 5-6 ft. A weak 1016 mb high centered offshore near 24N117.5W extends a ridge SE 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 high pressure is expected to collapse by 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. 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. A middle to upper level low pressure center is shifting westward across south central Mexico tonight and helping to enhance evening convection along the Pacific coast from Puerto Vallarta to Manzanillo, and will likely produce very active convection again tonight across the Pacific coasts from Puerto Angel to Manzanillo. Farther south, long period SW swell will move into the offshore waters between Puerto Angel and Baja California Sur Tue through Wed, with 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. 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 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 will spread into the regional waters tonight 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 23.5N136W and estimated at 1014 mb. Winds continue near 20 to 25 kt across the NW quadrant, with 6 to 9 ft seas within 120 nm. This low pres center was moving slowly westward last night but has begun to gradually accelerate this afternoon to 10-15 kt and will continue to movement over the next few days and slowly dissipate as it approaches 140W Tue evening. The remnant low of former tropical cyclone John is centered near 28N121W and estimated at 1014 mb is moving SE and will weaken to a trough 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