000 AXPZ20 KNHC 232153 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2021 UTC Tue May 23 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 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N86W to 12N100W to 08N114W TO 08N121W. The intertropical convergence zone axis extends from 08N121W to 07N140W. Scattered moderate and isolated strong convection is within 150 nm on either side of the monsoon trough. Isolated moderate convection prevails within 100 nm on either side of the ITCZ. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak pressure gradient prevails across the area supporting moderate NW winds prevailing across the Baja peninsula waters, and light NW to W winds from Las Tres Marias to Acapulco. Seas of 4 to 6 ft in mixed NW and SW swell and will subside to 4 to 5 ft by tonight. The pressure gradient will tighten somewhat N of 20N Wednesday through Friday as the ridge builds modestly into the region, with winds and seas increasing slightly. In the Gulf of California, mainly light and variable winds are expected through Thursday, with seas of 2 ft or less, except 3 to 4 ft near the entrance. Low pressure will deepen just N of the area over SW Arizona by Wednesday night through the end of the week. A trough will extend from the low across the northern Gulf to Baja California Norte. Fresh to strong southerly winds will develop SE of the trough Wednesday night, and then again on Thursday night as winds become enhanced through the gaps in the higher terrain of Baja. Seas will increase significantly, reaching 6 to 7 ft each night during the nocturnal wind max. S of 16N including the Gulf of Tehuantepec, broad and weak low pressure has persisted across the offshore waters SW of Tehuantepec the past few days, drifting to the W. Gentle to moderate SE winds occurring between Tehuantepec and offshore of Acapulco will gradually weaken and veer SW through Wednesday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh SE winds prevail between the Papagayo region and Tehuantepec, with seas of 5 to 7 ft in SW swell. Expect these conditions to continue today before gentle to moderate SW to W monsoonal winds spread N of 09N and into the coastal waters tonight into early Wednesday. Nocturnal offshore winds will pulse to fresh levels near the Gulf of Papagayo by Saturday night. Moderate SW winds are expected S of 09N through Thursday night, with seas subsiding through Wednesday before a new pulse of SW swell arrives Thursday through late Friday. Otherwise, little change is anticipated through the upcoming weekend. REMAINDER OF THE AREA... A weak ridge extends from 30N140W SE to near 12N110W. The ridge will drift by Wednesday as a weak front or trough moves SE across the waters N of 30N by early Wednesday, accompanied by long period NW swell. This will build seas to 6 to 8 ft from 30N to 32N between 120W and 135W. Elsewhere N of the convergence zone, the weak ridge will maintain moderate trade winds S of 18N, with seas of 5 to 7 ft expected. Little change is anticipated through the upcoming weekend. $$ ERA