000 AXPZ20 KNHC 082154 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2058 UTC Tue Sep 8 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 2120 UTC. ...TROPICAL WAVES... A tropical wave has been repositioned with the 1800 UTC analysis along 98W-99W, N of 05N to the coast of Mexico, moving west at 10-15 kt. Associated convection is described below and extend inland across the Sierra Madre Occidentales. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N74W TO 10N82W TO 14N92W TO 14N105W, then resumes from 1008 mb low pressure near 19.5N114.5W to 12N127W to 13.5N134W to beyond 11N140W. Scattered moderate isolated strong convection is noted from 06N to 13N between 78W and 92W. Scattered moderate to strong convection is noted from 08N to 16N between 94W and 112W, and also within 180 nm S of the trough west of 116W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Former T.S. Julio has been absorbed by a large 1008 mb surface low located to the south of the former cyclone, analyzed near 19.5N114.5W. Afternoon scatterometer data show a very well defined cyclonic circulation extending some 600 nm wide, with winds mostly 15 kt or less. Scattered moderate isolated strong convection is seen within 240 nm across the SW quadrant, where scatterometer data depicted NW to W 15-20 kt winds. Environmental conditions are marginally conducive for some development during the next few days while the low moves slowly southwestward. This system has a low chance of tropical cyclone formation through 5 days. A ridge across the eastern slopes of the Sierra Madre Oriental in Mexico was supporting a weak northerly gap wind event across the Tehuantepec region last night. The ridge has weakened and now mainly moderate northeast to east winds are noted over the Gulf of Tehuantepec. The forecast calls for light and variable winds in this area over the next several days. As is normal for this time of the year, mainly SE to S winds prevail across the Gulf of California. A trough extend across the far northern part of the Gulf from a 1000 mb low pressure center along the border of southern California and Arizona, and supports fresh to strong S-SE winds N of 28N based on afternoon scatterometer data. These winds will persist through Tue, then shift to the NW Tue night and Wed as a strong high pressure settles over the Great Basin area. These northerly winds will build 20-30 kt with seas expected to briefly build to 6-9 ft N of 29N early on Wed. Mainly light to gentle W to NW winds and seas in the 4-6 ft range will prevail across the offshore waters W of Baja California through mid-week as a broad cyclonic circulation dominates the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to locally fresh SW winds will prevail S of the monsoon trough through the forecast period while light and variable winds are expected N of it. The trough is expected to meander offshore of NW Nicaragua for the next few days. Seas will be in the 5 to 7 ft range in long-period southerly swell. REMAINDER OF THE AREA... A ridge dominates the waters N of 20N W of 120W. Gentle to moderate winds prevail north of the monsoon trough. Moderate to fresh southerly flow persists south of the monsoon trough, with zones of 7 to 8 ft seas. Long-period southerly swell is spreading northward across the region E of 120W, reaching the offshore forecast waters of Mexico, Central America, Colombia and Ecuador with seas in the 5 to 7 ft range. Seas will slightly subside toward the end of the work-week. $$ Stripling