000 AXPZ20 KNHC 182121 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2120 UTC Fri Oct 18 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... Tropical Storm Octave is centered near 11.0N 126.6W at 18/2100 UTC moving N at 4 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Recent GOES-17 visible satellite imagery indicates the low-level center of Octave remains exposed with limited moderate convection noted within 60 nm west semicircle. The storm is expected to meander or make a slow clockwise loop during the next few days. Additional weakening is forecast during the next day or two, and Octave could degenerate into a remnant low tonight or on Sat. 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 85W south of 16N, moving west around 10-15 kt. Scattered moderate convection is noted from 03N to 07N between 78W and 85W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N76W to 10N86W to 15N93W to 1011 mb low pressure near 15N111W to 10N123W, then resumes west of T.S. Octave from 10N130W to 10N140W. Scattered moderate isolated strong convection is noted from 12N to 19N between 99W and 107W. Elsewhere, scattered moderate convection is occurring within 180 nm south of the monsoon trough west of 130W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A set of large NW to N swell propagating across the Baja California Norte offshore waters will spread southeastward and reach the Revillagigedo Islands by Sat night. Wave heights will peak around 13 ft west of Guadalupe Island tonight. Fresh to strong NW to N winds will continue across the Baja California Norte offshore zones through the weekend. Moderate to fresh NW winds will develop in the northern and central Gulf of California late Sun night and continue through Tue night. Elsewhere, weak low pressure persists over the waters south of Cabo Corrientes near 19N105W. Scattered moderate convection is noted within 180 nm NW quadrant of the low. This feature is expected to drift SE and dissipate later this weekend. Another low pressure near 15N111W along the monsoon trough will move eastward and pass across the southern offshore waters this weekend. This feature will likely produce gusty showers and thunderstorms with locally heavy rainfall as it remains embedded within a moist and unstable offshore environment. Fresh to strong monsoonal flow will continue over the offshore waters south and southwest of the Tehuantepec region through Sat. Looking ahead, strong northerly winds will develop across the Gulf of Tehuantepec beginning late Tue night as high pressure builds behind a cold front crossing the Gulf of Mexico. Associated seas will likely build to 8 ft just downstream of the Gulf of Tehuantepec on Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Generally, moderate SW to W winds will prevail across much of the region through early next week. Fresh SW flow will develop south of Panama and west of Colombia Sat night and persist through Sun, with seas building to 8 ft. Then, wave heights will subside early next week as offshore wind speeds diminish. REMAINDER OF THE AREA... Please see the Special Features section for more details about Tropical Storm Octave. A 1011 mb low pressure is embedded in the monsoon trough near 15N111W. This low is forecast to drift eastward and weaken to a trough as it approaches the west-central coast of Mexico late this weekend. Elsewhere, a large set of NW swell is propagating across the northern waters, with seas 8 ft or greater north of a line from 29N115W to 18N140W. Earlier altimeter data showed an area of 10-13 ft seas was located north of 28N along 127W/128W. This swell will continue propagating southeastward through the weekend. Expect seas 8 ft or greater north of 10N and west of 110W by Sun, with fresh to strong N winds maintaining 12 ft seas north of 27N between 118W and 123W. This swell will gradually decay early next week. Otherwise, a high pressure ridge extends across the waters north of 20N. Recent scatterometer data indicates mainly moderate NE winds north of the monsoon trough and west of 125W. Moderate to locally fresh S to SW winds are found south of the monsoon trough, with seas generally 5-7 ft. $$ Reinhart