000 AXPZ20 KNHC 291545 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Oct 29 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 1009 mb surface low is embedded within the monsoon trough at 11N107W accompanied by scattered moderate isolated strong convection within 330 nm over the SW semicircle of the low center. Fresh winds and seas to 8 ft are forecast within 180 nm over the NE semicircle 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 Pacific coast of Colombia at 09N78W across the northern Gulf of Panama and northern Panama to the Pacific coast of Costa Rica at 10N85W, then continues westward through embedded surface lows at 11N107W and 09N119W to 09N127W where scatterometer winds indicate a transition to an ITCZ, which then continues W to beyond 08N140W. Isolated moderate to strong convection is observed within 90 nm either side of a line from 06N77W to 11N90W to 09N95W to 10N104W. Scattered moderate isolated strong convection is noted within 150 nm either side of lines from 12N96W to 15N104W to 10N114W, and from 09N124W to 08N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extending SE from 22.5N116W to 15N100W will shift slightly SW during the next few days as a weak trough meanders E and W across the Baja California Peninsula. The pressure gradient is tightening across the northern waters, with fresh NW winds, and 7 to 11 ft seas, forecast to spread SE across the N of 25N W of the Baja Peninsula through Tue night. Winds and seas will then diminish and subside with gentle northerly winds then expected through the upcoming weekend, except becoming briefly moderate within 60 nm of the northern and central Baja coast. Light to gentle anticyclonic flow expected elsewhere across the Mexican offshore waters W of 100W. Gulf of California: A moderate southerly breeze is developing across the waters N of 30N to the S of a surface low expected near 31N115W tonight. The low will shift E of the area on Tue night, dragging a cold front S across the northern gulf waters followed by strong northerly winds N of 30N on Wed. Fresh NW winds are forecast across the entire gulf waters on Wed night into Thu, and moderate NW winds forecast on Thu night through Fri night. Gulf of Tehuantepec...Strong to near gale force northerly drainage flow expected across and downstream of the gulf waters to along 13.5N through early Tue morning. The associated N-NE swell, in the form of 8 to 11 ft seas, will reach along 11N between 94W and 100W today. Expect winds 20 kt or less and seas less than 8 ft by early Tue night. Model guidance suggests that the next strong to near gale force gap event will begin on Fri night with hints of minimal gale conditions on Sat night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Fresh to locally strong NE flow is forecast to diminish today while the associated 7 to 10 ft seas will gradually subside through late Tue. Light to gentle variable winds, and 3 to 6 ft seas are forecast elsewhere N of the monsoon trough 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 11N107W. A 1008 mb low pressure center is centered near 09N119W. The low will track westward for a few days accompanied by fresh winds and seas to 8 ft, with a low chance of tropical cyclone development. Long period NW swell, in the form of 8 to 11 ft seas, currently W of a line from 32N120W to 16N140W, will continue to propagate E across the discussion area reaching a line from the northern Baja Peninsula to 10N137W overnight. These swells will subside with seas forecast to less than 8 ft on Thu. In addition, a surge of strong northerly winds accompanied by 9 to 13 ft seas, will move into the waters N of 29.5N between 120W and 127W through late Tue before diminishing. 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