000 AXPZ20 KNHC 170912 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Sep 17 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 0845 UTC. ...TROPICAL WAVES... The axis of a tropical wave extends along 94W north of 05N, moving west at around 10 kt. Scattered moderate convection is noted N of 14N between 90W and 96W. The axis of a tropical wave extends along 110W from 00N to 10N, moving west at around 15 kt. No significant convection is noted at this time with this feature. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N86W to 11N119W. The ITCZ continues from 11N119W to 11N140W. Aside from convection discussed in the tropical wave section above, scattered moderate convection is noted from 09N to 13N and E of 97W, and from 07N to 11N between 116W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Latest scatterometer data depicts gentle to moderate NW winds west of the Baja California peninsula. Seas remain in the 5 to 6 ft range. Light to gentle variable winds and seas of 5-6 ft are noted elsewhere over the S and SW Mexico offshore waters with seas in the 5 to 6 ft range as indicated by recent altimeter data. In the Gulf of California, winds are also light to gentle and variable, with seas to 3 ft. For the forecast, gentle to moderate winds, occasionally fresh, will prevail across the waters west of Baja California through Mon late in the afternoon, when winds will diminish to light to gentle. However, seas will remain in the 5 to 6 ft range due to long period SW swell combining with long period N swell early next week. SE winds will develop along the Gulf of California tonight and will continue through Fri night. Moderate southerly winds will resume along the gulf on Mon and diminish again Mon night. Otherwise, light to gentle variable winds will prevail elsewhere through Tue next week with seas to 5 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate southerly flow dominate across much of the forecast waters S of 10N with seas in the 6 to 7 ft range in SW swell. Light to gentle variable winds with 5 to 6 ft seas are over the remainder offshore zones N of 10N. For the forecast, SW swell across the region will subside today. A second round of SW swell will move across the area during the weekend through early next week, which will sustain seas to 6 ft across the area with mainly moderate southerly winds S of 10N. Otherwise, moderate to locally fresh winds will pulse in the Papagayo region Fri through Mon. REMAINDER OF THE AREA... A surface trough extends from 28N123W to 25N127W. Surface ridging is to the NW of this trough, which is supporting moderate to fresh NE winds N of the monsoon trough to nearly 24N. Seas are in the 5 to 6 ft range in this region. Gentle to moderate southerly winds dominate elsewhere S of the monsoon trough. Seas are generally in the 5-7 ft range. Little change in the weather conditions is expected through the forecast period. A frontal boundary is expected to approach from the NW and stall along 30N by late this weekend and linger in this area through early next week. NW swell will build seas to around 8 ft along and near 30N just W of the Baja California offshore waters. $$ ERA