000 AXPZ20 KNHC 300945 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Nov 30 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Pacific coast of Colombia at 08N78W across the northern Gulf of Panama to the Pacific coast of Costa Rica at 09N84W, then continues W to 08N96W, then turns NW 11N114W, then drops SW through embedded 1010 mb surface lows at 09N124W and 08N128W. Scatterometer winds indicate a transition to an ITCZ which extends W from 08N129W to beyond 07N140W. Isolated moderate to strong convection is observed within 120 nm either side of a line from 07N82W to 09N104W to 11N111W to 08N127W. A surface trough is analyzed from 11N104W to 17N102W with isolated moderate to strong convection noted within 90 nm of 16N99.5W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: A cold front will sweep E across the northern gulf waters today accompanied by a strong to near gale force SW-W-NW wind shift, with seas building briefly to 7 ft. Gentle to moderate variable winds then expected across the entire gulf through Sat night. Strong W to NW flow is forecast N of 29.5N on Sun, with fresh northerly winds developing across the entire gulf late Mon, with locally strong conditions near 26.5N111W on Mon night. Gulf of Tehuatepec...Light to gentle, mostly onshore, flow forecast till late Mon night when moderate northerly drainage flow will develop. Strong to near gale force winds expected by late Tue morning, and minimal gale force conditions expected on Tue evening, with a tightening pressure gradient supporting 35 to 45 kt strong gale conditions on Wed. Elsewhere: Long period NW swell is mixing with long period cross-equatorial southerly swell, resulting to combined seas of 8 to 15 ft across the open Pacific waters N of 13N. The highest seas are N of 28N in predominately NW swell, with seas of 12 ft or greater expected to reach as far S as 23N tonight before beginning to subside. These seas will gradually subside to less than 8 ft by late Mon morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Pulses of fresh NE winds expected through the middle of next week. Light to locally moderate northerly flow, and 3 to 5 ft seas, is forecast elsewhere N of the monsoon trough which is meandering between 08N and 11N, while moderate southwesterly monsoonal flow, with 4 to 6 ft seas, is forecast S of the monsoon trough through the upcoming weekend. REMAINDER OF THE AREA... A NW to SE ridge extends from 32N140W to 20N110W, bridging through a frontal trough that is washing out from 30N115W to 22N140W. Long period NW swell is mixing with long period cross- equatorial southerly swell, resulting in combined seas of 8 to 17 ft across the discussion waters W of 105W. The NW swell is building the highest seas N of 27N. These seas will subside from the W to less than 8 ft by late Mon morning across the waters E of 125W. Fresh to strong southerly winds will develop N of a ridge from 32N130W to 23N140W on Sat night, with seas 8 to 12 ft reaching 30N140W around sunrise on Sun ahead of a cold front that will reach a position from 32N138W to 29N140W late Sun. The front will reach from 32N128W to 21N140W early Tue, preceded by strong SW flow N of 29N within 240 nm E of the front, and fresh to strong westerly winds and large 8 to 16 ft seas W of the front. $$ Nelson