000 AXPZ20 KNHC 122133 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2133 UTC Fri Apr 12 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N78W to 06N100W. The ITCZ continues from 06N100W to 08N110W to 03N130W to 03N140W. Scattered moderate showers and isolated thunderstorms are active from 04N to 07N between 90W and 100W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends from a 1035 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. Gulf of California: Gap winds to gale force over the northern Gulf along 30N have diminished this afternoon. A scatterometer pass from 18 UTC showed another westerly gap wind area near 28N with winds to 25 kt. Winds and seas will diminish through the afternoon and early evening as deep low pressure north of the area shifts eastward. 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 Gulf of Mexico. Winds are forecast to suddenly increase to 35-40 kt, with seas building to 12 or 13 ft by early Mon morning. 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. 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. Under the influence of this system, scatterometer data indicate a large area of fresh to strong northerly winds covering the waters W of a line from 30N116W to 20N125W to 10N130W, with seas of 10 to 14 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. At this time, seas of 8 to 9 ft are expected N of 20N W of 113W, and from 05N to 20N W of 128W. 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