000 AXPZ20 KNHC 141609 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon May 14 2018 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 1515 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N77W TO 11.5N90W TO 10N100W TO low pres near 12N114.5W 1011 MB TO 04N127W, then transitions to ITCZ from 04N128W to beyond 06N140W. Scattered moderate to strong convection is noted from 03.5N TO 10N BETWEEN 78W AND 82W, FROM 06N TO 15.5N BETWEEN 85W AND 96W, AND FROM 04N TO 09N BETWEEN 99W AND 109W. Scattered moderate to strong convection is also noted within 150 NM EITHER SIDE OF TROUGH AND LOW FROM 111W TO 124W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A NW to SE oriented high pressure ridge is present across the offshore waters west of Baja California, producing gentle to moderate northwest winds over those waters. These winds will continue through this afternoon, then freshen tonight through Wed and then become fresh to locally strong Wed night as the ridge strengthens slightly. Recent altimeter data indicates that seas are currently in the 5-8 ft range and will persist through early Wed then build slightly to 6-9 ft in mixed SW swell and fresh NNW wind swell. Gulf of California: S to SW winds of around 15 kt are over the northern sector of the Gulf of California from 29N to 31N west of 114W. These winds become light and variable tonight. Gentle to moderate NW winds will continue across the remainder of the Gulf through Wed, except for a brief instance of fresh to strong northwest winds near and along the coast of Mexico from 24N to 26N on Tue night. Gulf of Tehuantepec: Light to moderate NW to N winds will prevail across the Gulf region today, then become SW to W at gentle to moderate speeds tonight as broad and deep layered troughing across the Gulf of Mexico extends further SW into the Yucatan Peninsula and Central America. This trough is forecast to linger across the southern Gulf of Mexico and Central America through most of the week, and will allow for winds across the Tehuantepec region to become variable, and mostly onshore during the day, and offshore at night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: light to gentle winds will dominate the gulf most of the forecast period with seas of 4-6 ft in long period SW swell, building to 5-7 ft Wed night as another round of long period SW swell reaches the coast of Central America. Gulf of Panama: Gentle to moderate S to SW winds are forecast during the next several days, with seas of 4-6 ft in long period southerly swell, building to 5-7 ft Wed night as long period SW swell reaches the coasts of Panama and Colombia. Elsewhere, gentle to moderate southwest winds are expected to the south of the monsoon trough with axis meander roughly along 10N, with light to gentle variable winds north of trough. Seas are forecast to build to 6-7 ft in long period SW swell between Ecuador and the Galapagos Islands beginning on Tue. REMAINDER OF THE AREA... A ridge extends from the NW waters southeastward to near the Revillagigedo Islands. Low pressure, remnants of recent Tropical Depression One-E, is drifting southward near 12N130W with a central pressure of 1011 mb. The small cyclonic circulation of the low is clearly exposed and becoming elongated with time. Moderate to fresh north to northeast winds are within 240 nm of the low in the NW quadrant and 180 nm in the NE quadrant. The low is forecast to weaken to a trough late on Tue as it drifts southward, and while at the same time the high pressure to its north begins to build southward. Decaying NW swell is propagating through the waters north of 20N between Baja California and 126W, where seas are peaking around 8 ft. Expect seas W of 117W to subside to less than 8 ft by late tonight. Seas to 9 ft in SW swell, combining to some extent with NE wind waves are present from 13N to 20N between 113W and 134W. This area of seas 8 ft and greater will gradually shift westward through Wed while shrinking in coverage, and remain confined to the trade wind belt. As described above, a 1011 mb low remains embedded within the monsoon through near 12N114.5W. deep convection is somewhat removed from the low itself but is scattered about the monsoon trough axis from 111W TO 124W. Global models indicated that the low should persist over the next 48 to 72 hours as it tracks in a general west to west- southwest direction under the southern periphery of building high pressure. $$ Stripling