000 AXPZ20 KNHC 171529 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Jun 17 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 1200 UTC surface analysis and satellite imagery through 1430 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N76W TO 09N83W TO 15.5N97W TO 09N113W TO low pres near 09.5N126W 1010 mb. The ITCZ extends from 09N121W to beyond 06.5N140W. Scattered moderate to strong convection is N of 05.5N E of 91W, and also N of 06N between 91W and 98W, including the Gulf of Tehuantepec. Scattered moderate to strong convection is noted from 08.5N to 11N between 101W and 111W. Broad low pressure is forecast to continue for the next few days across most of Central America, the western Caribbean, and Eastern Mexico. Additionally, a large area of disturbed weather over the W Caribbean will track NW across the Yucatan Peninsula this weekend, and into the southern and central Gulf of Mexico early next week. Locally heavy rainfall accumulations are possible as large clusters of TSTMs develop over the next few days. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A NW to SE orientated ridge will meander across the EPAC waters well to the W of the offshore zones through Wed night, while a NW to SE orientated trough will meander E to W across the Baja Peninsula and Gulf of California. A gentle to locally moderate NW breeze is forecast across the offshore waters W of 112W through late Sun, then the low level flow will increase to a moderate NW breeze through late Mon, with these conditions continuing to the W of 114W on Tue and Wed, as a N to S trough develops along 112W. Fresh to strong northerly drainage winds are expected across the Gulf of Tehuantepec Mon night through Wed night as the disturbance currently across the W Caribbean moves NW across the Yucatan Peninsula. Large SW to S swell is forecast across the waters S of 14N beginning on Sun night. Light and variable winds expected elsewhere across the open Pacific waters through early Sat when a moderate W breeze will develop, and continue through Sun before diminishing. Large NW swell will propagate S and reach near 30N120W on Tue, and near 27N120W on Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The broad low pressure currently dominating central America and the adjacent regional waters is expected to maintain a moderate SW to W breeze across the entire forecast area through at least Wed night. Long period S swell will build seas to 6 to 9 ft across the waters S of 02N through this afternoon, and across the entire offshore waters by late Sun. These seas will begin to subside on Sun night, with seas less than 8 ft by late Wed. REMAINDER OF THE AREA... A ridge axis extends from a surface high near 33N136W SE to near 11N114W. This ridge will shift W over the weekend, terminating near 11N127W on Tue and Wed as broad low pressure develops along 115W to the N of the monsoon trough. Moderate to fresh anticyclonic flow is forecast across the discussion area through Sun, with seas of 7 to 9 ft to the NE of the ridge between about 120W and 125W. Fresh trades across the tropics to the SW of the ridge will support an area of 6 to 8 ft seas from 06N to 13N to the W of 135W through the evening, then then shift W of the area tonight. An area of 6 to 8 ft seas, primarily due to SW swell, is a observed S of 14N between 95W and 112W. These seas will be reinforced by a new pulse of cross equatorial southerly swell, spreading N across the equator. Expect 7 to 9 ft seas across the tropics to the E of 120W through Mon before subsiding occurs Mon night into Tue. Expect 4 to 6 ft seas to the lee of the Galapagos Islands. This S swell should subside to less than 8 ft by late Wed. $$ Stripling