000 AXPZ20 KNHC 192110 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2110 UTC Sat Oct 19 2019 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Post-Tropical Cyclone Octave is centered near 11.6N 125.7W at 19/2100 UTC moving ENE at 2 kt. Estimated minimum central pressure is 1009 mb. Maximum sustained wind speed is 30 kt with gusts to 35 kt. No convection is associated with Octave based on recent satellite imagery and available lightning data. A slow and erratic motion with little change in strength is expected during the next few days. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 89W south of 16N, moving west around 10 kt. Scattered moderate convection is noted from 09N to 11N between 87W and 90W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N76W to 10N84W to 17N100W to 1007 mb low pressure near 17N104W to 11N122W, then resumes west of Octave near 11N129W to 10N140W. Scattered moderate isolated strong convection is noted from 13N to 19N between 101W and 107W, and within 120 nm of the monsoon trough west of 134W. Scattered moderate convection is occurring from 04N to 08N between 79W and 84W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Large NW to N swell is producing 8-12 ft seas across the Baja California offshore waters, with 12-13 ft seas noted in earlier altimeter data west of Guadalupe Island. Fresh to strong NW to N winds will maintain an area of 12+ ft seas over the Baja California Norte waters west of 118W through Sun. A weakening offshore pressure gradient will allow wind speeds to diminish west of Baja early next week, and decaying swell will allow seas to subside below 8 ft by Tue. Weak low pressure near 17N104W is producing a large area of disorganized showers and thunderstorms. Some development of this system is possible before it moves inland over west-central Mexico and dissipates by late Sun. Heavy rainfall associated with this disturbance could produce flash flooding and mudslides across portions of Michoacan, Colima, and Jalisco, especially in areas of mountainous terrain, during the next few days. This system has a low chance of tropical cyclone formation. Elsewhere, fresh monsoonal flow well south of Acapulco is producing an area of 8-9 ft seas over the outer offshore waters. These conditions will diminish Sun night into Mon. Moderate to fresh NW winds will develop over the northern and central Gulf of California late Sun night and continue through Tue night. Strong northerly gap winds are expected across the Gulf of Tehuantepec late Tue night through Wed, with seas building to 8 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate SW to W winds will prevail across much of the region through the middle of next week. Freshening SW flow between Colombia and the Galapagos Islands, combined with SW swell, will build seas to 8 ft south of Panama on Sun. Wave heights will subside early next week as offshore wind speeds diminish and swell decays over the region. Looking ahead, another set of long period SW swell will move northward into the area by Thu. REMAINDER OF THE AREA... Please see the Special Features section for more details about Post-Tropical Cyclone Octave. A large set of NW swell has spread across the northern waters, with seas 8 ft or greater found north of a line from 21N113W to 10N140W. A 17 UTC altimeter pass revealed 12 ft seas extend at least as far southward as 26N124W. This swell will continue propagating southeastward well beyond the Revillagigedo Islands through the weekend. The swell will gradually decay early next week, and seas will subside below 8 ft across most of the region by Tue. Elsewhere, a high pressure ridge extends across the waters north of 20N. Recent scatterometer data just before 18 UTC indicated moderate to fresh NE winds prevail over the region north of 18N and west of 125W. Another area of fresh winds was noted in association with weak low pressure centered near 10N137W along the monsoon trough. This system is expected to drift westward over the next couple days. $$ Reinhart