000 AXPZ20 KNHC 260738 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Sep 26 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 0600 UTC surface analysis and satellite imagery through 0730 UTC. ...TROPICAL WAVES... A tropical wave is along 96W, from 02N to 15N, moving west at around 10 kt. Precipitable water animations and wave diagnostics show a clear wave signal propagating westward off of Central America the past couple of days. Associated convection is described below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia from 1009 mb low pressure near 10.5N74W to across northern Costa Rica and the Papagayo region at 10N86W to 10N110W to 12N120W to 09N134W. The ITCZ extends from 09N134W to 08N140W. Scattered moderate and isolated strong convection is noted from 02N to 09N between 77W and 81W, from 12N to 14N between 88W and 92W, from 05N to 13N between 94W and 105W, from 13N to 17N between 97W and 100W, and from 07N to 16N between 117W and 133W. Similar convection is noted from 17N to 24N between 103W and 108W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to near gale force N-NE winds are noted in the Gulf of Tehuantepec along with seas of 5 to 8 ft. Moderate NW-N winds are noted west of Baja California and in the central and southern Gulf of California. Light to gentle winds are noted elsewhere. Seas are 4 to 7 ft across the remainder of the open waters, and 2 to 4 ft in the Gulf of California, except 3 ft or less in the northern Gulf. For the forecast, fresh to strong northerly gap winds will continue across the Gulf of Tehuantepec through tonight. Mainly moderate NW-N winds will prevail west of Baja California, pulsing to fresh during the afternoon through evening hours. S-SW winds will pulse to moderate to fresh in the northern Gulf of California. Otherwise, gentle to moderate winds will prevail. Large NW swell will impact the waters west of Baja California by late Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to locally strong offshore winds prevail across the Papagayo region, with light to gentle winds elsewhere north of the monsoon trough. Gentle to moderate S-SW winds are south of the monsoon trough. Seas are in the 4 to 6 ft range from offshore of Colombia northward, and 5 to 7 ft in SW swell offshore of Ecuador. For the forecast, moderate to fresh offshore winds will pulse across the Papagayo region, occasionally to strong. Otherwise, light to gentle winds will prevail north of the monsoon trough, with mainly moderate winds south of the monsoon trough. Cross equatorial SW swell will propagate through the regional waters through early Tue. REMAINDER OF THE AREA... A surface trough extends from 23N130W to 1014 mb low pressure near 20N132W to 16N131W. Associated convection has dissipated. Moderate to locally fresh NE-E winds are northwest of the trough. Broad and weak ridging and gentle to moderate trades dominate the remainder of the open waters north of the convergence zone. Gentle to moderate southerly winds prevail south of the convergence zone. Seas are in the 5 to 7 ft range north of 11N, and 6 to 7 ft south of 11N, except locally to 8 ft between 93W and 115W. For the forecast, winds associated with the trough along 130W will gradually diminish through late Sun as it shifts westward and weakens. A cold front is expected to move into the NW waters Mon night into early Tue and quickly weaken as it moves southward and gradually dissipates along 21N by the end of the week. Associated long period NW swell is expected to build seas to 8 to 11 ft to the west of 120W, spreading southward through the middle of this coming week. $$ Lewitsky