000 AXPZ20 KNHC 200930 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0930 UTC Tue Nov 20 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 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong to near gale force northerly winds will pulse across the gulf waters through this coming afternoon. Stronger drainage flow this evening will result in minimal gale force conditions developing and then continuing through Wed morning. Associated seas are forecast to build to up to 12 ft near 15N95.5W late tonight. The northerly winds are forecast to gradually diminish through Fri morning. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N75W to 08N90W to low pressure near 06.5N104W. The intertropical convergence zone axis extends from there to 06N114W to 07N124W to 10N130W to low pressure near 10N139W. Scattered moderate and isolated strong convection is from 06N to 09N to the E of 84W, from 05N to 08N between 94W and 105W, from 08N to 11N between 116W and 120W, and also from 07N to 10N between 126W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features section for Gulf of Tehuantepec Gale Warning information. Gulf of California: Light NW flow is forecast across the entire gulf waters through this coming evening, increasing to moderate in the southern waters late tonight into Wed. Winds will increase to moderate to fresh across the entire gulf waters by the end of the week as the pressure gradient increases. A 1018 mb surface high is meandering near 27.5N118W with a ridge extending across the Mexican offshore waters W of 97W. Gentle to locally moderate anticyclonic flow is forecast around the meandering ridge through early Thu, except a weakening cold front will shift E across the waters N of 28N on Wed, accompanied by a light and variable wind shift. The pressure gradient will tighten on Thu with fresh northerly winds developing across the open waters W of 100W with locally strong NW flow N of 28N on Fri night through Sat. Additionally, long-period NW swell, in the form of 7 to 9 ft seas, will arrive at 32N120W late Thu, and reach the northern coast of the Baja Peninsula early Fri, with these swells propagating as far S as 23N late Fri night through Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Volcanic ash emissions associated with the Fuego Volcano in southern Guatemala have diminished with no plume currently evident or forecast over the offshore waters areas. Gulf of Papagayo: Fresh to locally strong NE winds with seas building briefly to 8 ft are expected through early Fri. Expect moderate to fresh NE flow Fri night, and then only moderate Sat night. Light to locally moderate northerly flow is forecast elsewhere N of the monsoon trough, while moderate southwesterly monsoonal flow, with 4 to 6 ft seas, is forecast S of the monsoon trough this week and into the upcoming weekend. REMAINDER OF THE AREA... A cold front extends from 32N121W to 24N127W then stationary to 23N133W accompanied by a moderate SW-W-NW wind shift. Low pressure of 1010 mb is near 30N130W with another cold front extending from the low to 28N133W to 27N135W to 28N138W. Seas to 8 ft in NW swell are in the vicinity of this front, but will subside in the next few hours. A third cold front is approaching 30N140W. This next front will reach from 30N130W to 26N134W to 24N140W by early Wed, then from 30N121W to 25N126W to 22N135W by early Thu. A new set of NW swell will arrive behind the boundary with seas building to up to 13 ft along and N of 30N early Wed through early Thu. A weak 1010 mb surface low is analyzed at 10N139W. Scattered moderate and isolated strong convection is from 06N to 13N between 132W and 140W. A surface trough is to the NE extending from 23N116W to 07N122W. The low and trough will continue W accompanied by fresh breeze E winds and seas to 8 ft through early Wed. A ridge will build in from the NW while the low and trough continue W resulting in a tightening pressure gradient. Fresh to strong NE trades and seas building to 8 to 11 ft are forecast from roughly 12N to 21N W of 120W by Wed. These conditions will persist across the same general area through the end of the week and into the upcoming weekend. $$ Lewitsky