000 AXPZ20 KNHC 272141 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1958 UTC Tue Feb 27 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 05N83W to 02N100W to 04N110W to 09N122W to 07N140W. A cluster of moderate to isolated strong convection is from 06N-08N W of 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Pacific waters west of the Baja California Peninsula: A ridge dominates the offshore waters and extends SE to beyond the Revillagigedo Islands. A series of weak cold fronts or troughs are forecast to sweep E across the northern offshore waters into the Gulf of California. One of this fronts currently extends from 31N115W to 26N130W. The most recent scatterometer data indicate fresh to strong NW-N winds behind the front. A set of long period NW swell also follows the front. Seas of 8-15 ft will dominate the waters N of 25N W of 116W tonight. This swell event will continue to propagate SE across the waters W of Baja California Peninsula, with seas in the 8-11 ft range affecting the waters N of 21N W of 113W by Wed evening. Seas of 8-9 ft are still expected N of the Revillagigedo Islands early on Thu. Gulf of Tehuantepec: An ASCAT pass from around 1530 UTC showed fresh northerly winds downstream of the Gulf to about 14N95W. Light and variable winds are expected through Thu, with the exception of moderate to locally fresh northerly winds at night. Then, winds are forecast to increase to 25-30 kt by Thu night, with gale conditions possible Fri and Fri night. Seas are expected to build to 11 or 12 ft downstream to near 14N95.5W by Fri night into early Sat morning. Gulf of California: A strong SW breeze along 30N will continue ahead of a cold front that currently extends from 31N115W to 26N130W. This front will drift E across the northern Gulf waters through tonight, with strong NW winds forecast behind the front this evening. Fresh to locally strong NW flow is expected across the central waters on Wed, with these strong conditions shifting S across the waters from 19N to 23N E of 110W to include the southern approach to Gulf of California on Wed afternoon through Thu morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The Fuego Volcano inland over Southern Guatemala near at 14.3N 90.9W is currently producing intermittent volcanic ash emissions over land, and the plume extends only about 40 nm west of summit. Model guidance indicates a westward movement of the plume over land during the next 12-18 hours. Gulf of Papagayo: Fresh to strong NE winds will continue to pulse through and downstream of the Gulf of Papagayo through Sat, with seas building to 8 ft. Marine guidance indicates increasing winds of 20-30 kt and building seas of 8-9 ft Sat night, and again Sun night. Gulf of Panama: N-NE 20-25 kt winds and seas of 7-8 ft are expected tonight, and again Sun night. The remainder of the forecast period expect northerly winds in the 15-20 kt range and seas of 5-8 ft. Elsewhere, gentle to moderate offshore flow will prevail N of 07.5N while light to gentle SW winds are forecast S of 07.5N. REMAINDER OF THE AREA... Strong high pressure of 1038 mb located NW of the area near 35N144W extends a ridge SE across the forecast waters to beyond the Revillagigedo Islands. The pressure gradient between the high and lower pressure in the vicinity of the ITCZ is supporting fresh to strong NE trades, and seas of 8 to 13 ft primarily in NE swell, across the tropical waters N of the convergence zone and W of 115W. These marine conditions will persist over the next 48 hours. As previously mentioned, a cold front is moving across the N waters followed by fresh to strong NW-N winds and building seas of up to 15 ft in northerly swell. Model guidance indicates that the pressure gradient will relax some late on Thu as the high pressure slightly weaken while moving westward, and a new cold front reaches the far northern forecast waters. $$ GR