000 AXPZ20 KNHC 250345 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Oct 25 2018 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 0300 UTC. ...TROPICAL WAVE... A tropical wave is analyzed N of 03N along 98W with scattered moderate isolated strong convection flaring S of 11N within 180 nm of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia at 09N76W across Panama to the Pacific coast of Costa Rica at 09N84W then turns W-SW through a tropical wave at 09N99W to 07N108W, then resumes at 19N104W and continues SW through embedded surface lows at 13.5N117.5W and 11N123W to 11N122W where scatterometer winds indicate a transition to an ITCZ, which then continues W to beyond 08N140W. Scattered moderate isolated strong convection is observed within 120 nm over the NE quadrant of the surface low at 13.5N117.5W and within 120 nm over the S semicircle of the surface low at 11N123W. Scattered moderate isolated strong convection is noted elsewhere within 120 nm either side of a line from 08N85W to 10N100W, within 30 nm of 13N108W, and within 150 nm either side of a line from 12N133W to 09N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge will meander from 22.5N to 14.597W through the upcoming weekend with light to gentle anticyclonic flow forecast around the ridge, except gentle to locally moderate NW flow is expected W of the Baja California Peninsula through Fri night. Gulf of California: Light and variable winds will become a gentle NW breeze by Fri morning, and a moderate NW breeze on Fri night and then continue through Sat night. Gulf of Tehuantepec...Gentle onshore flow is forecast during the daylight hours, and gentle to locally moderate offshore drainage expected nocturnally through late Sat. Model guidance suggests the next strong northerly drainage event will begin on Sat evening, increase slightly to near gale conditions late at night through late Mon, with gale force conditions possible on Mon evening through Tue morning. Guidance indicates the northerly winds will diminish to 20 kt or less late Wed. Extended outlook...Strong N winds and 8 to 15 ft seas, will propagate S into the waters N of 29.5N E of 120W on Mon night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Fresh NE flow will diminish to a moderate breeze at sunrise Thu, and then continue through late Sun when fresh NE flow is forecast to begin and then continue through late Tue. Light and variable winds, and 3 to 6 ft seas are forecast elsewhere N of the monsoon trough through the upcoming weekend, while moderate southwesterly monsoonal flow, with 5 to 7 ft seas, is forecast S of the monsoon trough. REMAINDER OF THE AREA... A 1011 mb low near 13.5N117.5W will drift W for about a day before turning SW and dissipating on Fri. A 1011 mb surface low has developed along the monsoon trough at 11N123W and is expected to move W and dissipate by Sat. A surface high meandering over the far NW waters is forecast to shift NE to near 32N133W by Fri, and lift N of 32N on Fri night. Mixing swell will result in a large area of 7 to 9 ft seas N of the ITCZ and W of 130W through Sat. NW swell in the form of 7 to 9 ft seas, will reach along 28N between 122W and 130W on Fri, then subside to less than 8 ft Fri night. A cold front will reach a line from 32N137W to 29N140W on Sat night followed by 8 to 10 ft seas. Although the front will wash out on Sun, the associated post-frontal NW swell will propagate E across the discussion area reaching a line from 32N127W to 17N140W on Sun night, and reach from the northern Baja California Peninsula to 10N140W on Mon night as a surge of strong northerly winds, and 10 to 15 ft seas, moves into the waters N of 29.5N between 118W and 125W. $$ Nelson