000 AXPZ20 KNHC 180302 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 302 UTC Thu Jun 18 2020 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...TROPICAL WAVES... A tropical wave is along 96W, moving west at 10 kt. No significant convection is observed within 120 nm of the wave axis. A tropical wave is along 107W/108W, moving west 10 kt. Scattered moderate to strong convection is ongoing from 09N to 12N within 120 nm of the wave axis. A tropical wave is analyzed along 124W/125W, moving west around 10 to 15 kt. This wave is well represented in low level satellite derived wind fields and lower level precipitable water fields also, largely due to its position to the southeast of an upper trough. Scattered moderate convection is active within 120 nm west of the wave axis from 08N to 12N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 11N115W to 13N123W to 08.5N140W. Scattered moderate to strong convection is active from 10N to 13N between 100W and 115W. Scattered moderate convection is active from 10N to 13N between 120W and 135W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong northerly gap winds spilling across the Gulf of Tehuantepec the past to days have diminished to 15-20 kt earlier, with associated seas now 6-7 ft. The pattern maintaining this gap wind event has shifted SE of the area and no significant gap winds are expected here for the next few days. Brief pulses of fresh gap winds may return by late Sat. Farther north, a deep layer ridge west of the area is building eastward following a sharp trough now extending from the southern Rockies through the central part of the Baja California Sur and into the open Pacific to 22N130W. This has tightened the pressure gradient enough at the surface to support moderate to fresh SW gap winds across portions of the northern Gulf of California, pulsing to strong gap winds during the evening and night time hours. The gradient will relax through late in the week as the ridge continues to build eastward. Meanwhile NW swell producing seas of 7 to 8 ft in the outer offshore waters of Baja California Norte will subside tonight, before another pulse of NW swell to 8 ft will enter the waters northwest of Guadalupe Island by through late today. Looking ahead, moderate to fresh NW winds are possible off Baja California Sur by late week as a ridge builds into the area. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW monsoon flow prevails south of the monsoon trough, with gentle to moderate winds to the north of the monsoon trough. Seas are in the 5-7 ft range, mainly south of Panama. This will subside through mid week, but another round of SW swell is expected Thu through Fri. REMAINDER OF THE AREA... A ridge extends from 1031 mb high pressure centered near 38N138W E-SE to just N of the Revillagigedo Islands. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh trade winds from 10N to 30N west of 125W. Seas are in the 7 to 9 ft range over this area in a mix of swell. Moderate to fresh winds, and seas of 5 to 7 ft, prevail elsewhere north of the monsoon trough/ITCZ. Moderate southerly flow prevails south of the monsoon trough/ITCZ. Long-period southerly swell still dominates the waters south of 10N and east of 110W, with 6 to 8 ft seas prevailing. Another round of southerly swell will enter the area late in the week. $$ Christensen