166 AXPZ20 KNHC 081451 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1418 UTC Wed Aug 8 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Hurricane John centered near 20.7N 112.3W at 08/1500 UTC or 185 nm (350 km) SW of the southern tip of Baja California, moving toward the NW or 320 degrees at 10 kt. Estimated minimum central pressure is 979 mb. Maximum sustained winds are 75 kt with gusts to 90 kt. Weakening is forecast during the next few days, and John is expected to become a tropical storm on Thursday, and degenerate into a remnant low late Friday or early Saturday. Numerous moderate to strong convection is within 90 nm of the center, and scattered moderate isolated strong convection is noted elsewhere within 180 nm E semicircle of the center. An outher band of this large hurricane is produccing locally heavy rainfall over Southern Baja California. John is expected to produce total rain accumulations of 1 to 2 inches over far southern Baja California Sur, with isolated maximum amounts of 3 inches through Thursday. Swells generated by John are affecting portions of the coasts of southwestern Mexico and the southern portion of the Baja California peninsula and will spread northward along the west coast of the Baja California peninsula during the next couple of days. The swells are forecast to reach the coast of southern California by late Thursday. These swells are likely to cause life-threatening surf and rip current conditions. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP2/WTPZ32 KNHC for more details. Tropical Storm Kristy centered near 14.4N 129.3W at 08/1500 UTC,or about 1210 nm (2245 km) WSW of the southern tip of Baja California, moving WNW or 290 degrees at 7 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained winds are 40 kt with gusts to 50 kt. Some slow strengthening is forecast during the next couple of days. Scattered moderate to strong convection is within 120 nm E and 60 nm W semicircles of the center, and scattered moderate isolated strong convection is elsewhere within 150 nm E and 90 nm W of the center. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across parts of Panama and Costa Rica to 10N85W to 11N100W to 12N110W stretches from 08N78W to 09N110W. Scattered moderate convection is noted within 60 nm either side of the trough axis west of 107W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features Paragraph above for details on Hurricane John. John is expected to affect the offshore waters between Manzanillo and Baja California Sur with winds and seas through Friday night. Gulf of Tehuantepec: Moderate to fresh nocturnal northerly drainage flow is expected in and up to 120 nm downstream of the gulf through Fri night. Gulf of California: Large southerly swell from John will cause seas S of 25N to build to 8-12 ft with S winds will increase to 20-25 kt through tonight as the hurricane moves NW, passing SW of Cabo San Lucas. Outside of Hurricane John, a weak pressure pattern will be in place through the end of the week due to weak ridging NW of the area. A large extratropical low pressure system W of California and Oregon will maintain a weaker pressure gradient and support gentle to moderate winds over forecast waters. The extratropical low is expected to weaken this weekend, allowing the ridge to rebuild. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh NE to E nocturnal flow is expected through the end of this week. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough, which will meander between 07N and 11N. Moderate to locally fresh S to SW winds are expected S of the trough through the end of this week. 4-6 ft seas will generally prevail, except for 6- 7 ft seas near the Galapagos Islands. REMAINDER OF THE AREA... See the Special Features Paragraph above for details regarding Hurricane John and Tropical Storm Kristy, which will affect the waters N of 10N during the next several days. Large swell will propagate well away from from Hurricane John through the end of this week as a large system. The areas of 8 ft seas generated by swell from Hurricane John and Tropical Storm Kristy will merge on Thu, with a large area of 8 ft seas likely enveloping most of the waters N of 15N and W of 110W the remainder of this week. Ridging N of the area will weaken during the next few days as John and Kristy dominate the synoptic environment. John will have the most effect on the ridge due to its large size. Strong NW winds west of California will produce N swell that will cause seas to build to 7-8 ft N of 30N between 120W and 124W tonight. $$ GR