000 AXPZ20 KNHC 212208 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Jul 21 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 2100 UTC. ...TROPICAL WAVES... A tropical wave is along 94W/95W, from 03N northward into southern Mexico, moving west at around 10 kt. Another tropical wave is near 101W, from 03N northward into southern Mexico, moving west at around 10 kt. Scattered moderate to isolated strong convection is active between the tropical waves from 09N to 12N between 95W and 97W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1008 mb low pressure over the far southwest Caribbean near 09N76W, across Panama to 07N97W to 11N127W to beyond 09N140W. Scattered moderate convection is evident from 05N to 07N between 82W and 89W, from 10N to 13N between 105W and 112W, and from 11N to 13N between 115W and 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A recent scatterometer satellite pass indicates 20 to 25 kt northerly gap winds in the Gulf of Tehuatepec. This is related to a passing tropical wave. Seas are estimated to be 4 to 6 ft in the Tehuantepec area. Light to gentle breezes with 3 to 5 ft seas are evident elsewhere off southern Mexico, with a component of SW swell. A few showers and thunderstorms are active ahead of the tropical wave beyond 90 nm off the coast of Chiapas. Farther north, the scatterometer pass also indicates mainly moderate NW winds across the waters off Baja California, between weak high pressure west of the region and lower pressure across northern Mexico. A concurrent altimeter pass shows 4 to 6 ft seas in this area. Gentle SE to S winds and slight seas are noted over the Gulf of California. A few showers may be ongoing near Tiburon Island over the northern Gulf of California. For the forecast, the fresh to strong N winds will continue to pulse across the Tehuantepec region through Sat night. Moderate to locally fresh winds offshore of Baja California will diminish by the end of the week. Moderate to locally fresh SE flow will develop in the Gulf of California Thu through Sat. Winds and seas may be higher in the Gulf of California in the evenings as showers and thunderstorms over mainland Mexico move into the Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... High pressure over the NW Caribbean is helping to funnel fresh to strong NE to E winds over the Papagayo region with seas to 8 ft. Elsewhere, moderate or weaker winds prevail. Seas are 4 to 6 ft, primarily in long period SW swell. Scattered showers and thunderstorms are active beyond 150 nm off Costa Rica and western Panama, on the south side of the monsoon trough. For the forecast, High pressure over the NW Caribbean will continue to support fresh to strong NE to E winds over the Papagayo region through at least Sat, mainly during the overnight and early morning hours. Moderate or weaker winds are forecast elsewhere. A moderate southerly swell will impact the waters west of Ecuador by Thu. Winds will freshen south of the monsoon trough this weekend allowing for seas to build across the waters north of 02N. REMAINDER OF THE AREA... The remnant low pressure of what was Guillermo is near 17N132W, with an estimated pressure of 1010 mb. There is no shower or thunderstorm near this feature, and a recent scatterometer satellite pass indicated a large area of moderate to fresh NE winds on the northwest side of the low pressure, between the low and ridging dominating the waters north of 20N and west of 120W. Seas are estimating to be 8 to 9 ft related to this. Altimeter data is showing seas below 8 ft in the waters from 10N to 12N west of 135W, where some lingering seas from the remnant low of what was Felicia were noted earlier. For the forecast, the remnant low of Guillermo will open up to a trough with diminishing winds through the end of the week, while associated seas will be slower to decay. Otherwise, the ridge will linger across the waters north of the convergence zone with fairly tranquil marine conditions expected as Felicia departs and as Guillermo spins down. $$ Christensen