000 AXPZ20 KNHC 012118 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1942 UTC Tue Aug 1 2017 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. ...SPECIAL FEATURES... Irwin has weakened to a remnant low and the last advisory on this tropical cyclone was issued by The National Hurricane Center at 01/2100 UTC. At this time, the remnant low of Irwin is centered near 26.6N 129.7W moving NNW at 7 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is within 90 nm in the N quadrant of Irwin. Dissipation is expected during the next day or so. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 for more details. ...TROPICAL WAVES... A tropical wave extends from the Gulf of Tehuantepec area at 15N94W to 1010 mb low pressure near 11N94W to 06N94W, moving W around 10 kt. Scattered moderate convection is noted from 11N to 14.5N between 93W and 96W. An earlier scatterometer pass provided observations of 20-25 kt winds within 180 nm NE semicircle of low center supporting seas to 8 ft. These conditions will continue to shift W-NW offshore of Mexico during the next few days while the low and tropical wave parallel the coast. A second tropical wave extends from 17N102W to 08N102W moving W at 10 to 15 kt. Scattered moderate convection is within 150 nm E of wave axis N of 10N. A tropical wave is from 08N to 15N along 112W/113W moving slowly W. Convection is limited at this time. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N79W to low pressure near 11N94W to 10N110W to 09N122W. The intertropical convergence zone axis continues from 09N122W to 07N140W. Scattered moderate convection is from 06N to 10N between 90W and 103W. Similar convection is from 06N to 10N between 115W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A narrow ridge is noted between the Baja California Peninsula and to the E of the remnant lows of Hilary and Irwin located roughly between 127W and 135W. The pressure gradient is weakening under the influence of the ridge allowing for gentle to moderate NW winds offshore of Baja California with seas of 5 to 7 ft. Generally light to gentle winds will persist elsewhere over the offshore waters of Mexico, as well as in the Gulf of California. Long period southerly swells of 5 to 7 ft will gradually subside through the end of the week. An area of low pressure along a tropical wave near the Gulf of Tehuantepec region is forecast to continue to move W-NW and then more NW by the end of the week with associated winds and seas accompanying it, with the strongest winds and highest seas mainly on the NE side of the low center. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Low pressure located near 11N94W along a tropical wave S-SW of Guatemala and El Salvador will move away of the area by tonight. As a result, winds and seas will gradually diminish across the offshore forecast zone PMZ111 tonight into Wednesday. Otherwise, long period southerly swells of 5 to 8 ft will gradually subside through the end of the week. REMAINDER OF THE AREA... Please see the special features section for information on post-tropical cyclone/remnant low of Irwin. The remnant low of Hilary is near 28N134W based on visible satellite imagery. A trough is analyzed in this area on the 1800 UTC analysis/surface map. The trough will persist tonight into Wednesday. Another ridge dominates the NW corner of the forecast area. Mainly moderate trade winds will prevail between the convergence zone and 18N west of 120W. Seas of 6-8 ft in southerly swell will cover the waters S of 12N-14N W of 100W on Wednesday, and S of 10N between 110W and 126W, and S of 16N between 126W and 140W on Thursday. $$ GR