000 AXPZ20 KNHC 171613 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Jun 17 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 1200 UTC surface analysis and satellite imagery through 1510 UTC. ...TROPICAL WAVES... A tropical wave is along 94W, moving west at 10 kt. Scattered moderate to strong convection is noted from 06.5N to 14N between 86W and 100W. A tropical wave is along 106W, moving west 10 kt. Scattered moderate to strong convection is ongoing from 08N to 13N between 100W and 108W. A tropical wave is analyzed along 123W, 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. A broad area of active convection continues with this wave as it interacts with an upper low to its northwest. Scattered moderate to strong convection is active behind the wave from 07N to 13N between 110W and 120W, and within 150 nm N of the monsoon trough between 120W and 130W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N77W to 09N84W to 13N123W to 09N137W. The ITCZ continues from 09N137W to beyond 08.5N140W. Elsewhere outside of convection associated with tropical waves described above, scattered moderate isolated strong convection is noted from 07.5N to 11.5N between 130W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong northerly gap winds are spilling across the Gulf of Tehuantepec this morning, in a narrow 30 nm wide plume. This is occurring due to the pressure gradient between lower pressure over the southwest Gulf of Mexico and the higher terrain over southern Mexico. The lower pressure has been enhanced over the past couple of days by a mid to upper level trough extending across the region from the northeast Gulf of Mexico. This mid to upper trough is dampening out, so the pattern will change through tomorrow and the gap winds will taper off today. Seas are 8 ft downstream of the Gulf of Tehuantepec, mixing with longer period southerly swell. Looking ahead, gentle to moderate breezes will persist in Tehuantepec through most of the remainder of the week. 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 peninsula into the open Pacific to 22N130W. This is tightening the gradient enough at the surface to support brief pulses of fresh to strong gap winds into the northern Gulf of California currently. A brief repeat of the fresh to strong winds is possible tonight as well. 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 Wed. 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 34N138W E-SE to 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 25N 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. $$ Stripling