441 AXPZ20 KNHC 100946 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Aug 10 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 0900 UTC. ...SPECIAL FEATURES... Tropical Storm John is centered near 25.9N 119.9W at 0900 UTC or about 575 nm WNW of the southern tip of Baja California moving NW or 310 degrees at 9 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained winds have decreased to 40 kt with gusts to 50 kt. Latest satellite imagery shows scattered moderate convection within 90 nm NW and 60 nm SE of the center. Although the overall appearance of John had improved modestly tonight, convection has begun to diminish in the past few hours, and the tropical storm has already begun to weaken as it moves over cooler sea surface temperatures. This weakening trend will continue through Friday night as John is expected to reach near 27.4N 122.8W as a tropical depression then weaken to a post- tropical remnant low near 28.6N 124.4W by Sat night as it moves farther away from the Baja peninsula. Swells from John will continue to affect portions of the coasts of southwestern Mexico through Friday and the Baja California peninsula through Sat. Southerly swell has reached the coastal waters of southern California overnight and will produce large surf and strong rip current conditions there through Sat. Please consult products from your local weather office. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ32 KNHC for more details. Tropical Storm Kristy is centered near 18.2N 129.8W MB at 0900 UTC, moving NNE or 15 degrees at 8 kt. Estimated minimum central pressure is 991 mb. Maximum sustained winds remain at 60 kt with gusts to 75 kt. Latest satellite imagery shows that the cyclone continues to maintain it current intensity, but an eye feature seen developing in microwave imagery earlier tonight has yet to develop in the middle to upper portions of Kristy. It is possible that the window of opportunity to strengthen to a hurricane today has passed. Deep convection, in the form scattered moderate to strong intensity, is observed within 90 nm SW and 60 nm NE of the center, while scattered moderate to strong convection is seen elsewhere from 120 to 240 nm across the S semicircle. Kristy is expected to maintain is current intensity today as it moves slowly northward along 130W. Afterwards Kristy is expected to begin to gradually weaken as it moves over cooler waters and become nearly stationary on Sunday. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC for more details. ...TROPICAL WAVES... A tropical wave axis has been relocated to along 95W north of 05N moving westward at 10-15 kt. Scattered moderate to strong convection is located from 06N to 12N between 92W and 100W. A tropical wave axis is along 110W-111W from 04N to 18N, moving westward near 15 kt. Scattered moderate to strong convection is from 07N to 14N between 105W and 115W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N75W TO 05N79W TO 09N85W TO 07N98W TO low pres near 11.5N111W TO 15N119W, where it terminates. Scattered moderate to strong convection is noted from 06.5N to 12.5N east of 89W. Scattered strong convection continues along the coast 60 nm offshore of the Pacific coast of Mexico between 105W and 109W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section above for details on Tropical Storm John. Gulf of Tehuantepec: Moderate to fresh northerly flow northerly nocturnal drainage flow is expected to continue downstream of the gulf this morning, reaching to near 13N, with seas reaching a peak of about 7 ft. John is moving west-northwest away from the Baja California Peninsula. Swells propagating away from John are reaching the Baja California coastline and will continue through Fri. A weak ridge will build between John and Baja California Peninsula by Fri as the cyclone moves away from the offshore waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh northeast to east nocturnal winds will flow through the gulf tonight into early on Sun. Gentle to occasionally moderate east winds are forecast elsewhere N of the monsoon trough, with axis roughly 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 cross-equatorial SW swell. REMAINDER OF THE AREA... See the Special Features section above for details regarding Tropical Storms John and Kristy, which will affect the waters N of 13N W of 110W during the next several days. Large swell will propagate well away from John through Friday. The areas of 8 ft seas generated by swell from John and Kristy will merge later today, with a large area of 8 ft seas likely enveloping most of the waters N of 15N and W of 110W through Fri. A ridge will dominate the NW portion of the area this weekend. The pressure gradient between John and high pressure to the NW will bring increasing winds across the NW part of the forecast area Fri and through the weekend. $$ Stripling