000 AXPZ20 KNHC 182211 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2040 UTC. ...TROPICAL WAVES... A tropical wave is analyzed along 99W, moving west at 10-15 kt. Scattered moderate isolated strong convection is noted behind the wave from 06N to 15N between 88W and 99W. A tropical wave is analyzed along 120W, moving west near 20 kt. Scattered to locally numerous moderate to strong convection is noted from 09N to 15N between 117W and 125W. This low amplitude wave has accelerated in the past 24-36 hours. A tropical wave is analyzed along 136W, moving west around 15 kt. Isolated moderate convection is noted within 120 nm of the wave between 10N and 13N. ...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 87W. Scattered moderate to strong convection is noted within 120 nm either side of the trough between 126W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Afternoon scatterometer wind data shows that northerly gap winds have ended across the Gulf of Tehuantepec, where NE winds of 10-15 kt prevail and seas have subsided to 5-6 ft. No significant gap winds are expected here in the short term. 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 pressure gradient supports moderate to fresh SW gap winds across portions of the northern Gulf of California, and moderate to fresh NWly winds along the Baja coast from Punta Eugenia to Cabo San Lucas. The gradient across the northern Gulf of California will relax Fri 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. Looking ahead, moderate to fresh NW winds are expected across the waters of Baja California S of Punta Eugenia through the weekend 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 4-6 ft range, except to 7 ft well offshore and downstream from Papagayo. These 7 ft seas are the leading edge of another round of SW swell expected to arrive today through Fri. Winds S of the monsoon trough will also increase to moderate to fresh tonight through Fri evening and spread to the coasts between the Gulf of Panama and Costa Rica. REMAINDER OF THE AREA... A ridge extends from 1030 mb high pressure centered near 33N137W E-SE to just N of the the Revillagigedo Islands. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the monsoon trough is supporting fresh trade winds from 10N to 20N west of 120W. Seas are in the 6 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 and W of 120W. Moderate southerly flow prevails south of the monsoon trough/ITCZ. Long-period southerly swell still dominates the waters south of 12N and east of 115W, with 6 to 8 ft seas prevailing. Another round of southerly swell will enter the area today through Fri and act to raise seas heights 1-2 ft across waters S of 10N. $$ Stripling