000 AXPZ20 KNHC 200227 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0225 UTC Sun Oct 20 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...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 06N to 08N between 86W and 89W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N76W to 15N90W to 17.5N104W to 11N123W, then resumes from 11N129W to 10N140W. Scattered moderate isolated strong convection is occurring within 90 nm W semicircle of 1006 mb low pressure near 17.5N104W, and within 180 nm NE quadrant of 1009 mb low pressure near 10N137W. Scattered moderate convection is noted elsewhere from 05N to 10N between 80W and 85W, from 11N to 15N between 104W and 109W, and within 120 nm of the monsoon trough west of 134W. 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 12-14 ft seas likely 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 17.5N104W 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 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 Guerrero is producing an area of 8-10 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. Looking ahead, strong high pressure expected to build over the western United States Thu could support strong to near gale force northerly winds over the northern Gulf of California Thu night. 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 tonight into 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 the middle of next week. REMAINDER OF THE AREA... The remnant low of Octave is still centered near 11.6N125.8W this evening. No convection is associated with post-tropical Octave based on the latest satellite imagery and available lightning data. A slow and erratic motion is expected during the next few days as the low maintains 20-25 kt winds, primarily in the NW quadrant. Another low pressure is centered near 10N137W along the monsoon trough. Earlier scatterometer data showed fresh to locally strong winds in the northern semicircle of the low, with peak seas likely around 10 ft. Any development of this system should be slow while the it drifts westward during the next few days. This system is expected to move into the central Pacific basin by late Sun. This system has a low chance of tropical cyclone formation. A large set of NW swell continues spreading across the northern waters, with seas 8 ft or greater found north of a line from the Revillagigedo Islands to 10N140W. Earlier altimeter data revealed 12 ft seas extended at least as far southward as 26N124W. This swell will continue propagating southeastward well beyond the Revillagigedo Islands through Sun night. 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. Moderate to fresh NE winds were noted in scatterometer data from this afternoon over the waters north of 18N and west of 125W. Little change is expected over the next couple days. $$ Reinhart