000 AXPZ20 KNHC 130243 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 034 UTC Sat Apr 13 2019 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 0300 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec: The next gap wind event across the Tehuantepec region is expected Sun night into Mon as a ridge builds across the eastern slopes of the Sierra Madre mountains in Mexico, behind a cold front moving across the western Gulf of Mexico. Winds are forecast to suddenly increase to 35-40 kt, with seas building to 12 or 13 ft by early Mon. Climatologically, the first gale-force event of a season occurs in mid-October, with the final gale-force event occurring in late March or early April. Occasionally, gale force events may occur as early as September and as late as May. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N78W to 08N110W. The ITCZ continues from 08N110W to 04N125W to 03N140W. Scattered moderate showers and isolated thunderstorms are active from 04N to 07N between 80W and 100W. Scattered moderate showers and isolated thunderstorms also within 60 nm north of the ITCZ between 105W and 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends from a 1037 mb ridge near 36N142W to the southeast toward the Revillagigedo Islands and south of Baja California. A tight pressure gradient between the ridge and a low pressure center over southern Arizona supports fresh to strong NW winds across the waters off Baja California Norte. Associated NW swell of 12 to 15 ft is reaching as far south as Guadalupe Island, with 8 to 12 ft elsewhere over open waters as far south as Clarion Island. These marine conditions are forecast to gradually improve during the upcoming weekend as the high pressure weakens and moves westward. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Gentle to moderate winds will prevail across the Gulf through Sun. Then, winds will increase to a fresh to strong breeze Sun night through Tue night as high pressure builds N of the area. Seas are forecast to build to near 8 ft with the strongest winds. Gulf of Panama: Mainly light to gentle wind will prevail across the area the next several days. Seas will generally remain in the 4 to 6 ft range during the entire period due to long period SW swell. Elsewhere, light to gentle winds will persist the next several days. Wave heights between Ecuador and the Galapagos Islands will generally remain in the 5 to 7 ft range in long period SW swell. REMAINDER OF THE AREA... As previously mentioned, a strong high pressure of 1037 mb located near 36N142W dominates the forecast waters N of 15N and W of 110W. Earlier scatterometer data indicated a large area of fresh to strong northerly winds covering the waters mainly north of 15N and west of 125W, with seas of 10 to 13 ft based on altimeter data. Winds and seas are forecast to gradually diminish across the area during the upcoming weekend as the high pressure weakens and moves westward. A new set of long period NW swell will reach the NW corner of the forecast region by Sat. Cross equatorial SW swell will bring seas to 8 ft S of 02.5S between 95W and 110W on Sat, and S of 02S between 104W and 115W on Sun. $$ Christensen