000 AXPZ20 KNHC 292122 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Aug 29 2023 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Irwin has become a post-tropical cyclone as of 29/2100 UTC and is centered near 19.1N 130.3W, moving west at 15 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are 17 ft. Seas of 12 ft or greater are within 120 nm of the center in the NE quadrant, 90 nm NW quadrant, and 45 nm S semicircle, as confirmed by a 29/1700 UTC satellite altimeter pass. Latest satellite imagery shows no deep convection associated with Irwin. Only isolated showers are within 150 nm of the center. Winds of 30-35 kt are mostly confined to the northern semicircle. Winds of 20-25 kt extend several hundred nm N and NW of the center. The remnant low of Irwin is forecast to continue moving westward, with a slower motion expected later this week. The cyclone should be below gale force in about 12 hours. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the final Irwin NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the Costa Rica border near 10N86W to 15N112W. The monsoon trough resumes from 12N130W to 09N140W. Scattered moderate convection is noted from 10N to 12.5N between 90W and 92W, from 11.5N to 16N between 96.5W and 101W, and from 10N to 18N between 107W and 112W. Scattered moderate to isolated strong convection is seen from 05.5N to 10N between 135W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Surface high pressure ridging extends southeastward from a 1030 mb high pressure near 35N140W toward the waters west of the Baja California Peninsula. The pressure gradient between this high and lower pressure over Mexico is supporting moderate to fresh northwest to north winds offshore Baja California. Moderate to fresh SE to S winds are in the northern Gulf of California. Gentle to locally moderate winds prevail elsewhere. Seas of 6-9 ft prevail west of Baja California Norte with 5-7 ft west of Baja California Sur. Seas are 1-3 ft in the Gulf of California. Seas elsewhere offshore of Mexico are generally 4 to 5 ft. For the forecast, moderate to fresh NW winds west of Baja California north of Cabo San Lazaro will persist through Wed. Northerly swell with seas of 8 to 9 ft will persist northwest of Punta Eugenia through tonight, then gradually subside by Thu. Fresh to locally strong SE to S winds will pulse tonight in the Gulf of California. Fresh to locally strong S winds will return to the northern Gulf of California Thu night through Fri night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle southwest winds prevail across most of the offshore waters N of 02N along with seas of 4 to 5 ft in long- period south to southwest swell. Near the Galapagos Islands offshore waters, moderate SE winds with seas of 5-8 ft are present, due to long-period south swell. For the forecast, moderate south to southwest winds will prevail between the coast of Ecuador and the Galapagos Islands tonight through Fri. Southerly swell will increase seas to 7 to 9 ft across the Galapagos Island offshore waters tonight, persisting through early Thu before subsiding late Thu. Elsewhere, light to gentle variable winds will prevail through most of the week with slight to moderate seas in long-period SW swell. ...REMAINDER OF THE AREA... Please see the Special Features section for details on post-Tropical Cyclone Irwin. The pressure gradient between high pressure N of the area and Post-Tropical Cyclone Irwin is inducing a large area of fresh to strong NE winds extending from north of Irwin all the way to beyond 30N, across much of the area between 120W and 140W. Seas are 6 to 9 ft in the area, except higher closer in to Irwin. Mostly gentle winds are east of 125W from 05N to 20N with seas 5 to 6 ft. Moderate SE winds are found south of 05N. Long-period S swell is causing seas of 8 to 10 ft over the southern part of the area, to the south of 03N. For the forecast, Post-Tropical Cyclone Irwin is forecast to weaken to 30 kt late tonight near 19N132.5W, then move to near 19N138W late Thu morning and to near 19N 140.3W late Fri morning. Elsewhere, northerly swell will propagate through the open waters well W of Baja California through at least Thu night, keeping seas of 8-10 ft N of 26N and E of 130W. Southerly swell in the far southern waters will build seas to 8 to 10 ft through Wed night. This swell area could travel as far north as 06N between 92W-125W before subsiding Thu. Looking ahead, another long period S swell event will push northward across the Equator on Fri, with seas of 8-9 ft south of 05N and east of 120W into Sat before subsiding late in the weekend. $$ Hagen