000 AXPZ20 KNHC 070233 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Sep 07 2016 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. ...SPECIAL FEATURES... Hurricane Newton is centered near 27.3N 112.0W or about 10 sm e of Santa Rosalia Mexico at 0300 utc Sep 07. The estimated minimum central pressure is 985 mb, and maximum sustained winds are 65 KT gusting to 80 kt. Newton is moving n, or 350 degrees at 15 kt. Currently, scattered moderate isolated strong convection is observed within 75 nm either side of a line from 23.5N109W to 30N113.5W, including the Baja Peninsula and the Gulf of California. Newton is forecast to move north across the Gulf of California tonight, and move inland over mainland Mexico early Wed near 29.8N 111.8W with winds diminishing to tropical storm strength, and then weaken to a tropical depression well inland near 32.7N 110.5W late Wed, and dissipate early Thu. Large rainfall accumulations from Newton will bring the potential for life-threatening flash floods and mud slides over portions of southwest and western Mexico, including Baja California Sur, especially in areas of mountainous terrain. For more information on Newton see the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC. A broad area of low pressure embedded within the monsoon trough is analyzed near 13N122W, with an estimated pressure of 1008 mb at 0000 UTC. Scattered moderate isolated strong convection is currently observed within 75 nm either side of a line from 10N121W to 13N123W. This low is forecast to move to near 16N122W late Wed, and near 17N127W late Thu, with the possibility of tropical cyclone formation through the next five days as the low continue nw across the tropics. ...TROPICAL WAVES... The axis of a tropical wave extends N from 10N98W to near 20N98W, and has been moving w at about 15 kt. Isolated moderate and strong convection is noted within 60 nm either side of lines from 11N94W to 13N98W and from 13N101W to 11N104W. Model guidance suggests that a surface low will develop along this wave in a couple of days, and tropical cyclone formation will be possible in 3 to 5 days. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends wsw from the Pacific coast of Costa Rica at 11N86W to 07N100W the turns nw to 08N105W. The monsoon trough resumes w of an embedded low pressure center at 13N122W and continues w to beyond 13N140W. Scattered moderate isolated strong convection is noted to the n of 07N e of 83w including across the Gulf of Panama, and within 75 nm either side of a line from 10N121W to 13N123W in association with the low near 13N122W. Similar convection is noted within 60 nm either side of a line from 08N91W to 07N105W, within 120 nm of 11N113W, and within 120 nm either side of a line from 12N123W to 10N130W to 13N137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section above for the discussion on hurricane Newton. A sub-tropical ridge axis will rebuild on Wed with its axis extending from nw to se across the western portion of offshore zone PMZ015. Light to gentle anticyconic flow is expected through Thu, then moderate nw flow will develop and along the Pacific coast of the Baja Peninsula on Fri, and persist through the weekend. A thermal trough will develop again over the Baja Peninsula and across the northern Gulf of California in the wake of Newton on Thu. This will maintain light and variable flow across the Gulf of California through the weekend, except increasing to a moderate sw flow between 30N and 31.5N during the late night hours. Fresh northerly drainage flow is forecast across, and just downstream of the Gulf of Tehuantepec during the overnight hours, except increasing to strong on Wed and Thu nights with seas building briefly to 9 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds forecast to the n of 07N through the period, while moderate sw to w flow is expected across the EPAC waters to the s of 07N. Forecast combined seas of 3 to 6 ft across the entire waters through the period. REMAINDER OF THE AREA... Except as previously mentioned in the special features section, a quasi-stationary surface ridge will extend from near 32N138W to near 20N115W. Moderate ne flow will continue through Sun to the s of the ridge and n of the monsoon trough, with combined seas of 4 to 6 ft. The gradient will tighten on Sun night into Mon with the trades increasing to 15-20 kt, as the tropical low previously described moves northwestward across the tropics. Fresh ne winds with combined seas of 7 to 9 ft are observed n of 27N w of 125W. The gradient will relax late this week with a surface high pressure developing near 28N125W. $$ Nelson