000 AXPZ20 KNHC 130912 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 912 UTC Sat Jun 13 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 83W, moving west near 10 kt. No significant convection is noted near this wave. The axis of a tropical wave is near 98W, moving west around 10 to 15 kt. No significant convection is noted near this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near 10N85W to 10N120W. The ITCZ continues from 10N120W to 11N130W, and from 11N135W to beyond 10N140W. Scattered moderate to isolated strong convection is ongoing within 120 nm off the coasts of El Salvador and Chiapas. Scattered moderate convection is observed from 08N to 10N between 93W and 96W, from 10N to 12N between 100W and 102W, and from 08N to 10N between 108W and 110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A couple of recent scatterometer satellite passes confirmed strong to near-gale force northerly gap winds persist into the Gulf of Tehuantepec this morning. A concurrent altimeter satellite pass indicated seas are 8 to 10 ft in the Gulf of Tehuantepec, due in part to the gap winds but also a component of longer period southerly swell. The strong to near-gale force winds are likely to persist through early next week between high pressure north of the area and lower pressure farther south into the tropics. Farther north, a deep layer trough is observed on satellite imagery moving across California and approaching Baja California Norte. An associated local surface trough is likely moving through northern Baja California and the northern Gulf of California currently. This is supporting moderate to fresh SW to W gap winds into the far northern Gulf of California through the early morning. The upper trough will allow low pressure to deepen over the lower Colorado River valley through tonight. This combined with high pressure building eastward will tighten the gradient enough to promote fresh to strong NW winds funneling closer to the coast north of 25N tonight into Sun. NW swell will persist off Baja California Norte into early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Recent scatterometer satellite passes indicated generally moderate SW flow south of the monsoon trough. Long-period southerly swell persists across the offshore waters with wave heights of 7-8 ft. North of the monsoon trough, winds remain mainly gentle to moderate, with seas in the 5-7 ft range in southerly swell. Fresh winds will pulse across the Papagayo region through early next week. Wave heights will briefly subside though Sun, before another set of southerly swell crosses the region late Sun through Mon, then decaying Tue before the next set arrives later in the week. REMAINDER OF THE AREA... A surface ridge extends from 1029 mb high pressure centered near 34N147W to the Revillagigedo Islands. Farther south, a surface trough is analyzed along the ITCZ near 131W. The gradient between this trough and the ridge to the north is supporting fresh to locally strong trade winds from 10N to 20N west of 135W, as confirmed by recent scatterometer satellite data. Seas are estimated to be at least 9 ft in this area, in mix of swell and shorter period seas from trade winds. Gentle to moderate winds prevail north of 20N, with seas in the 5-6 ft range. Little change is expected over the next couple days as the weak trough moves westward along the ITCZ and supports fresh to locally strong winds and locally higher seas west of 135W. Farther east, moderate to locally fresh southerly flow prevails south of the monsoon trough/ITCZ. Long-period southerly swell still dominates the waters south of 15N and east of 110W, with 7-8 ft seas south of the monsoon trough east of 110W. This swell will gradually decay over the next couple days, with wave heights subsiding below 8 ft today. $$ Christensen