000 AXPZ20 KNHC 130931 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 641 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec: The next gap wind event across the Tehuantepec region is expected Sun night and Mon as a ridge builds S along the eastern slopes of the Sierra Madre mountains in Mexico behind a cold front crossing the Gulf of Mexico. Winds are forecast to abruptly increase to between 35 and 40 kt. Corresponding seas will build as high as 13 ft by early Mon. Climatologically, the first gale-force gap wind event of the season occurs in mid October. The final gale-force gap wind event usually occurs in late March or early April. Occasionally, gale force events affect the Gulf of Tehuantepec as early as September and as late as May. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 05N77W to low pres 1010 mb near 07N95W to 08.5N107.5W. The ITCZ continues from 08.5N107.5W to 09N113W to 06N120W to 05N125w to beyond 02N140W. Scattered moderate and isolated strong convection is found within 30 nm of a line from 06N83W to 02.5N91W...within 90 nm of a line from 07.5N101W to 09N109W and from 05N to 07N between 136W and 139W. A second ITCZ stretches between 03.5S96W and 03S111W. Scattered moderate and isolated strong convection is present S of 02S between 97W and 101W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends SE from a 1033 mb high centered near 35N146W to near the Revillagigedo Islands. Strong winds W of Baja California Norte have subsided to fresh as high pressure NW of the area begins to weaken and deep low pressure over interior Mexico begins to fill. Winds and seas W of Baja will continue to diminish through Sun as the pressure gradient between the weakening high and filling low pressure relaxes. Please refer to the Special Feature section for additional details concerning the late season gale-force gap wind event expected to occur over teh Gulf of Tehuantepec Sun night and Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh winds will prevail over the Gulf of Papagayo through Mon, then become strong Mon night through Wed night as high pressure builds N of the area. Seas are forecast to peak near 8 ft when winds are strongest. Gulf of Panama: Gentle to moderate winds will generally prevail across the Gulf of Panama the next several days. Seas will generally range between 4 and 6 ft through Wed night in long period SW swell. Elsewhere, light to gentle winds will persist during 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, high pressure measuring 1033 mb centered near 35N146W still dominates the forecast waters N of 10N and W of 110W. Satellite-derived wind data obtained between 0530Z and 0730Z indicated a large area of moderate to fresh NE winds covering the waters mainly north of 10N and west of 120W, with seas of 8 to 11 ft based on satellite-derived sea height data. Winds and seas in this region are forecast to gradually diminish until Mon as the high weakens and retreats W. A new set of long period NW swell will reach the NW corner of the discussion area Tue evening. This round of swell will spread E and cause the waters W of Baja California Norte to build to between 8 and 9 ft Wed night through Thu night. Cross equatorial SW swell will cause combined seas to build to around 8 ft S of 02S between 98W and 118W through Sun. The SW swell will decay and allow seas in this area to fall below 8 ft by Tue morning. $$ CAM