923 AXPZ20 KNHC 110940 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Aug 11 2018 Updated Tropical Waves section 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. ...SPECIAL FEATURES... Tropical Storm Kristy is centered near 21.0N 130.4W at 0900 UTC, moving NNW or 345 degrees at 6 kt. Estimated minimum central pressure is now 999 mb. Maximum sustained winds have diminished to 40 kt with gusts to 50 kt. Latest satellite imagery suggests a weakening trend has begun, with the middle level center appearing to move NNW out ahead of the low level center. Strong convection has diminished, and scattered moderate isolated strong convection is now observed within 90 nm of the center except 45 nm across the SW quadrant. Kristy is forecast to gradually weaken tonight through this weekend as it veers northwestward and begins to move over colder sea surface temperatures, and is expected to weaken to a tropical depression by 24 hours. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC for more details. The post-Tropical storm remnant low of John is centered near 27.5N123W, moving NW near 8 kt. Estimated minimum central pressure is 1006 mb. Winds have diminished to 20-25 kt within 120 nm of the center across the NE semicircle, with seas of 8-11 ft, and will gradually diminish further over the next 24-36 hours as the low moves slowly WNW and weakens. ...TROPICAL WAVES... A tropical wave is along 100W-101W from 04N to 16N, moving westward at 12-15 kt. Scattered to locally numerous strong convection is from 06.5N to 15N between 97W and 107W. A tropical wave is along 115W from 04N to 17N, with a 1012 mb low pressure center near 11.5N114W, moving westward 10-15 kt. Satellite imagery shows widely scattered moderate isolated strong convection from 07.5N to 16N between 110W and 119W. More stable atmospheric conditions are expected ahead of the wave as it moves westward of 120W in the next few days, and the low center will likely dissipate within 36-48 hours. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N74W TO 08.5N93.5W TO LOW PRES NEAR 11.5N114W, where it terminates. The ITCZ extends from 14.5N132W to beyond 14N140W. Scattered moderate to strong convection is noted within 120 nm S of the trough between 80W and 95W. Scattered moderate to strong convection is within 60 nm either side of the ITCZ between 132W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Post-Tropical Storm John, now a low center, is moving west- northwest away from the Baja California Peninsula. Earlier SW swell generated from John will continue to move through the offshore waters and reach the Baja California coastline through Sat. Southerly swell has already peaked across the coastal waters of southern California on Friday but will continue to produce moderate to large surf and strong rip current conditions there through Sat. Please consult products from your local NWS office. Weak high pressure is building over the waters west of the Baja California Peninsula, and will last through at least the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh northeast to east winds will flow across the gulf and well downstream into early Sun, becoming strong each night through morning. Gentle to occasionally moderate east winds are forecast elsewhere N of the monsoon trough, with axis roughly meandering along 09N-10N. Moderate to locally fresh S to SW winds are expected S of the trough through the end of this week. Seas in the range of 4-6 ft will generally prevail, except for 6-7 ft seas near the Galapagos Islands. These seas will increase over the weekend to 7-9 ft due to a large area of long period cross- equatorial SW swell. REMAINDER OF THE AREA...See the Special Features section above for details Tropical Storm Kristy, where generated swell will continue to affect the waters N of 17N west of 125W through early next week. Seas generated by former Tropical Storm John and Kristy have combined to create an area of 8-9 ft seas to the N of 15N and W of 119W. These seas will last through Sat afternoon, then shrink in coverage Sat night through Sun. A ridge will dominate the NW portion of the area this weekend. The pressure gradient between the remnant low of John and high pressure to the NW will increase NE winds across much of the NW part of the forecast area through the weekend. $$ Stripling