000 AXPZ20 KNHC 150220 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Jun 15 2017 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 0215 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends w from the Pacific coast of Costa Rica at 10N85W to 10N110W, then turns SW to 06N127W where scatterometer winds indicate that the ITCZ forms, and continues NW through an embedded trough at 08N139W. Scattered moderate isolated strong convection is observed within 90 nm of the coast of Central America from 83W to 87W, within 150 nm either side of a line from 08N86W to 07N107W, and within 75 nm either side of a line from 09N106W to 04N123W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A nw to se orientated ridge extends across the EPAC waters just w of the offshore zones, while a heat trough is dissipating from NW to SE across the Baja Peninsula. Moderate to fresh NW winds currently across the offshore waters to the N of 20N will diminish to a gentle to moderate NW breeze late tonight, with little change then expected through Mon night, except increasing to a fresh breeze across near shore waters along the Central Baja Peninsula during the evenings. Large SW swell will reach the southern zones generally s of 14N on Sun night. This SW swell will begin to subside on Mon night. Gulf of California: Light and variable winds forecast through the period. Gulf of Tehuantepec: Light northerly drainage flow expected through Thu morning. Fresh n flow expected late Thu night. Model guidance is hinting at strong to near gale force northerly drainage winds on Mon night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds are forecast to the N of 09N late tonight, to the N of 10N on Thu, and to the N of 12N early Fri. Moderate southerly flow currently observed to the S of 09N, will spread N on Thu with a moderate SW to W breeze across the entire forecast area by late Fri, with little change through Mon night. Long period SW swell will build seas to 9 ft over the upcoming weekend. REMAINDER OF THE AREA... A ridge axis extends from 32N136W SE to near 08N125W. A surface high will shift S on Thu to near 32N137W, where it will meander through Fri night, with a ridge extending SE to near 10N120W. Moderate to fresh anticylonic flow is forecast across the area through Mon night, with seas of 7 to 9 ft to the N of the ridge between about 120W and 128W. A surface trough over the deep tropics from 06N140W to 10N135W will drift W of the area late Thu, with fresh NE winds and 6 to 8 ft seas expected to the W of the trough till then. An area of 6 to 8 ft seas, primarily due to SW swell, is a observed from 05N to 09N between 100W and 112W. The seas will subside below 8 ft on Fri as a batch of cross equatorial southwesterly swell, in the form of 7 to 9 ft seas, spreads N across the equator between 95W and 110W on Fri evening. Expect 7 to 9 ft seas across the tropics to the E of 120W on Sat through Mon before beginning to subside on Mon night. $$ Nelson