000 AXPZ20 KNHC 120945 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 628 UTC Mon Nov 12 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 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: The most recent scatterometer pass indicates fresh to strong northerly winds across the Gulf of Tehuantepec, with seas to 8 ft. These marine conditions will diminish by early this morning. On Tue, a strong cold front will move across the western Gulf of Mexico followed by strong high pressure system. Winds are forecast to first reach minimal gale force across the Gulf of Tehuantepec by Tue morning, then suddenly increase to 40-45 kt by early Tue afternoon as the strong high pressure over NE Mexico extends a ridge southward across the Mexican coastal plains. A very tight pressure gradient across the Isthmus of Tehunatepec is expected to support these very strong winds, which are forecast to reach minimal storm force (48-50 kt) by early Tue evening. Seas downstream of the Gulf of Tehuantepec are expected to build up to 19-21 ft by Tue night. Storm force winds are expected to persist through Wed evening, with gale force winds likely lasting into early Fri morning. Gale Warning along and near the west coast of northern Baja California: Strong high pressure building across the southwestern United States and northern Mexico will bring strong to near gale force northerly winds over the Gulf of California. These winds will funnel through mountain passages across north-central Baja California and bring mimimal gale force northeast winds over Baja California Norte and regional waters, particularly from 28N to 30N E of 115W-116W beginning Mon evening and continuing through Tue evening. Fresh to strong NE winds and building seas of 8-10 ft are also expected across the offshore forecast waters W of Baja California, mainly N of Cabo San Lazaro. ...TROPICAL WAVES... The axis of a tropical wave extends from 09N115W to 16N114W, moving westward at 10 to 15 kt. Isolated showers are near the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N76W to 06N95W to 07N107W. The ITCZ axis continues from 07N107W to a 1010 mb low pressure located near 08N117W to 09N130W to beyond 07N140W. Scattered moderate convection is noted from 06N to 10N between 110W and 114W. Scattered moderate isolated strong convection is seen from 07N to 10N between 126W and 134W. Similar convection is also near 08N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information on upcoming Gulf of Tehuantepec storm event and on a gale event near the west coast of Baja California Norte. Gulf of California: Strong high pressure N of the area is already producing fresh to strong NW winds across the northern Gulf as noted in a recent scatterometer pass. These winds will spread southward across the entire length of the Gulf of California and across the waters between Las Marias Islands and Los Cabos by Mon evening into Mon night. Seas are forecast to build to 8 to 10 ft before starting to subside Tue morning as the high pressure slightly shifts eastward. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to occasionally strong winds will pulse over the Gulf of Papagayo through late this morning, with moderate to fresh winds thereafter. Winds will increase back to fresh to strong by Wed night as a tight pressure gradient develops over northern Central America behind a strong cold front moving into the NW Caribbean. Seas are forecast to build to 9 ft by early Thu morning. A strong Tehunatepec gap wind event W of the area is forecast to spread strong to near gale force winds and building seas of 12 to 18 ft into the far SW portion of the offshore waters of Guatemala and El Salvador, particularly W of 93W, Tue night through Wed. Otherwise, light to gentle winds are forecast N of the monsoon trough, with gentle to moderate SW winds S of the monsoon trough through the next several days. Cross equatorial long period SW swell will keep seas in the 6 to 7 ft range between Ecuador and the Galapagos Islands, and as far north as near the Azuero Peninsula through Wed. REMAINDER OF THE AREA... High pressure of 1024 centered west of California near 35N128W extends a ridge SE across the northern forecast waters to near the Revillagigedo Islands. The pressure gradient is forecast to tighten between the high pressure and lower pressure in the vicinity of the ITCZ Mon night into Tue morning, resulting in fresh to locally strong trades just N of the ITCZ. Seas of 8 to 9 ft will be associated with these winds covering roughly the waters from 10N to 17N W of 120W by Tue. A cold front will attempt to approach 30N140W the next few days, but will stall and weaken just to the northwest of the area. A set of northwest swell associated with this front is forecast to cross 30N140W by early Wed, with seas of 8 to 10 ft covering much of the waters north of 10N W of 130W by early Thu. Cross equatorial SW swell of 7 to 9 ft will propagate across the waters S of 06N between 100W and 120W today through early Wed. $$ GR