000 AXPZ20 KNHC 281548 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Oct 28 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...SPECIAL FEATURE... A 1007 mb surface low is embedded within the monsoon trough at 10N102W accompanied by scattered moderate isolated strong convection within 120 nm E and 270 nm W semicircles of the center. Fresh winds and seas to 8 ft are forecast within 270 nm of the low as it continues westward with a medium chance of developing into a tropical cyclone during the next 3 to 5 days. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia at 09N76W across northern Panama to the Pacific coast of Costa Rica at 10N85W, then turns slighlty NW to 11N94W, then turns SW through embedded surface lows at 10N102W and 09N116W to 09N123W where scatterometer winds indicate a transition to an ITCZ, which then continues W to beyond 09N140W. Scattered moderate isolated strong convection is noted within 60 nm either side of a line from 05N77W to 08N80W to 09N86W, within 180 nm either side of a line from 14.5N92W to 07N94W, and elsewhere within 90 nm of line from 08N107W to 10N115W. Scattered moderate convection is observed within 90 nm of 16N115W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge will meander from 22.5N116W to 15N98W through early Mon with light to gentle anticyclonic flow forecast around the ridge. The pressure gradient will tighten on Mon afternoon with fresh NW winds, and 8 to 11 ft seas, arriving at 30N120W. Moderate NW flow, and 7 to 10 ft seas, are forecast N of 23N on Tue night. Winds and seas will then diminish and subside with gentle to locally moderate NW winds, and 4 to 6 ft seas forecast west of the mainland Mexico by late Thu. Gulf of California: Light and variable winds will become a moderate southerly breeze across the waters N of 30N late Mon. Moderate to locally fresh NW winds expected N of 30N on Tue night, then increasing to a strong breeze by late Wed, with these conditions spreading S across the gulf waters N of 27N on Wed evening. Gulf of Tehuantepec...Strong to near gale force northerly drainage flow expected across and downstream of the gulf waters to along 13.5N through late Tue morning. The associated N-NE swell, in the form of 8 ft seas, will reach along 12N between 95W and 98W late Mon. Model guidance suggests the gap event will begin on Fri evening, with hints of minimal gale force winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Fresh to locally strong NE flow, with 5 to 7 ft seas, is forecast through late Mon with these conditions expected to reach as far downstream as 10N87W. Light to gentle variable winds, and 3 to 6 ft seas are forecast elsewhere N of the monsoon trough through this week, while moderate southwesterly monsoonal flow, with 4 to 6 ft seas, is forecast S of the monsoon trough. REMAINDER OF THE AREA... See the special features paragraph concerning a surface low near 10N102W. A second 1008 mb low pressure center is centered near 09N116W. The low will track westward for a few days accompanied by fresh winds and seas to 8 ft and a low chance of tropical cyclone development. A weak cold front across the far NW waters will soon dissipate. However, associated NW swell, in the form of 8 to 11 ft seas, will propagate E across the discussion area reaching a line from 32N118W to 12N135W late Mon, just as a surge of strong northerly winds accompanied by 9 to 14 ft seas, moves into the waters N of 29.5N between 120W and 127W. The northerly winds will gradually diminish through late Tue night, with the NW swells subsiding and seas forecast less than 8 ft late Wed night. $$ Nelson