000 AXPZ20 KNHC 272118 AAA TWDEP Tropical Weather Discussion...Updated NWS National Hurricane Center Miami FL 1824 UTC Mon Sep 27 2021 Updated ITCZ/Monsoon Trough section 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 1200 UTC surface analysis and satellite imagery through 1815 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 104W, from 03N to 15N. It is moving westward at 10 to 15 kt. This wave is moving through a very moist environment. Scattered moderate to isolated strong convection is noted within 180 nm east of the wave from 10N-15N. Scattered moderate convection is within 240 nm east of the wave from 08N to 10N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...Updated The monsoon trough extends from 10N84W to low pressure near 10N86W 1010 MB to 10N110W to low pressure near 11N115W 1011 mb to low pressure near 12N128W 1010 mb and to 12N137W, where latest scatterometer data indicates the ITCZ begins and continues to beyond 08N140W. Aside from convection associated to the tropical wave along 104W, scattered moderate to isolated strong convection is south of the trough from 04N to 07N between 82W- 85W, also within 120 nm south of the trough between 115W-117W and within 60 nm north of trough between 116W-120W. Scattered moderate convection is within 120 nm south of the trough between 117W-119W, within 60 nm south of the trough between 94W-97W, also between 126W-128W and within 60 nm north of the trough between 118W-122W and between 124W-126W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh north to northeast winds continue across the Gulf of Tehuantepec area today. Associated seas across the area are in the range of 5-7 ft. Fresh northerly winds are noted over the waters west of the Baja California peninsula. light south to southwest winds are over the northern portion of the Gulf of California. Light to gentle winds are noted elsewhere. Seas are 4-7 ft across these open waters, and 2-4 ft in the Gulf of California. Mainly moderate northwest to north winds will prevail west of Baja California, pulsing to fresh during the afternoon through evening hours. The light south to southwest winds over the northern Gulf of California will increase to fresh speeds late tonight through mid-week in advance of an approaching cold front. Otherwise, gentle to moderate winds will prevail through Tue. Large northwest swell will impact the waters west of Baja California by late Tue as the aforementioned cold front begins to dissipate while moving southward across the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to fresh offshore winds prevail across and downwind of the Papagayo region, with light to gentle winds elsewhere north of the monsoon trough. Gentle to moderate west to southwest winds are south of the monsoon trough. Seas are in the 4-6 ft range from offshore of Colombia northward and offshore of Ecuador in southwest swell. Moderate to fresh offshore winds will pulse each night across the Papagayo region through mid-week. Otherwise, light to gentle winds will prevail north of the monsoon trough, with mainly moderate winds south of the monsoon trough. Cross-equatorial southwest swell will continue to propagate through the regional waters through early Tue. The swell will peak this evening. REMAINDER OF THE AREA... A surface trough extends from near 23N132W to 17N132W. Generally moderate northeast to east winds are present northwest of the trough, where seas are peaking to 7 ft. Broad and weak ridging along with gentle to moderate trades dominate the remainder of the open waters north of the convergence zone and west of about 118W. Gentle to moderate southerly winds prevail south of the convergence zone, except between 112W-120W where an overnight ASCAT pass revealed an area of fresh to strong southwest winds due to a stronger gradient present induced by the 1011 mb low near 11N115W. Seas are in the 5-7 ft range north of 11N, and 6 to 7 ft south of 11N, except higher seas of 8-9 ft are found between 105W-121W, mainly attributed to the fresh to strong southwest winds near the aforementioned 1011 mb low. Winds associated with the trough along 132W will diminish today as it shifts westward and weakens. A cold front will begin to move across the far northwest waters tonight, reach from near 30N132W to 28N140W early Tue and from near 30N118W to 26N140W by early Wed as it begins to dissipate. The front is forecast to gradually dissipate near 21N by the end of the week. Associated long-period northwest swell is expected to build seas to the range of 8-11 ft to the west of 120W, spreading southward through the end of the week while decaying. $$ Aguirre