952 AXPZ20 KNHC 180905 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Sep 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...TROPICAL WAVES... A tropical wave axis is along 114W from 02N to 17N, moving west at 10 to 15 kt. It shows up well in the lower half of the atmosphere, south of a upper level ridge. Scattered moderate convection is noted within 60 nm of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 12N91W to 13N104W, then resumes from 18N110W to 11N117W to 14N125W to 14N136W to 1009 mb low near 13N139W. Scattered moderate isolated strong convection is noted from 09N to 17N between 93W and 105W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak high pressure is building southward across the waters west of Baja California Norte, supporting moderate northerly winds and 5 ft seas across the offshore waters. This synoptic pattern will continue through Sun. Northerly 6-7 ft swell will build southward toward Baja California Norte this weekend. A weak surface trough will develop well to the west of Baja California Sur this weekend, which will maintain light to gentle winds and slight seas through early next week. Farther south, strong gap winds and building seas are possible in the Gulf of Tehuantepec region on Sun, related to developing Tropical Depression Twenty Two in the southwest Gulf of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate S to SW winds persist south of the monsoon trough. Elsewhere, gentle winds prevail north of the monsoon trough. Combined seas are currently in the 5 to 6 ft range in a mix of wind waves and southerly swell, with a maximum of 6-7 ft near Panama. The swell is starting to subside, and sea heights are expected to diminish today. REMAINDER OF THE AREA... The remnant low of Karina is located near 23N127W with a central pressure of 1010 mb. The most recent scatterometer data showed fresh winds north-northeast the low. Maximum seas are about 8 ft within 60 nm of the low. The low will continue to move westward and gradually weaken to a surface trough later today or tonight, and seas will subside below 8 ft tonight. A recent altimeter satellite pass indicated seas near 8 ft just north of a 1009 mb low pressure area along the monsoon trough near 13N139W. Winds are likely near 20 kt within 120 nm north of the low. Winds and seas associated with the low will shift west of the area later today. A small cluster of scattered showers and thunderstorms is noted near the low pressure. Farther east, seas are 7 to 8 ft in an area along the monsoon trough from 06N to 10N between 105W and 115W, a combination of moderate to fresh SW winds along with longer period SW swell. Winds and seas will diminish later today in this area. $$ Mundell