000 AXPZ20 KNHC 181601 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave is analyzed along 97W, moving west at 10 kt. Scattered moderate isolated strong convection is noted from 07.5N to 15.5N between 94W and 103W. A tropical wave is analyzed along 115W/116W, moving west 10 kt. Scattered moderate to strong convection is noted ahead of the wave from 09N to 14.5N between 115W and 120W. A tropical wave is analyzed along 133W, moving west around 10 to 15 kt. This wave position is west of the well represented low level satellite derived wind fields and lower level precipitable water fields seen between 122W and 130W, influenced by the persistent deep layered trough to the N and NW. Scattered moderate isolated strong convection is active within 120 nm either side of the monsoon trough between 130W and 140W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N76W to 10N90W to 13N123W to 09N140W. Convection occurring near tropical waves is described above. Elsewhere, scattered moderate isolated strong convection noted N of 06N E of 92W. Scattered moderate to strong convection is active from 09N to 14.5N between 120W and 129W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A narrow plume of fresh northerly gap winds is still active acrossthe central Gulf of Tehuantepec, where winds are assumed to be 15-25 kt, and seas 6-7 ft. These gap winds have been active in the Gulf of Tehuantepec for the past several days, but the supporting pattern has started to changed and the winds have been gradually subsiding. 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, and fresh NWly winds along the Baja coast from Punta Eugenia to Cabo San Lucas. The gradient across the northern Gulf of California 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. Another round of SW swell is expected to arrive today through Fri. REMAINDER OF THE AREA... A ridge extends from 1029 mb high pressure centered near 33N136W 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 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 today through Fri. $$ Stripling