000 AXPZ20 KNHC 131519 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1244 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A Gale Warning has been issued for the Gulf of Tehunatepec. 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 or 14 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. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the coast of Colombia near 05N77W to 07N90W to 07N100W to 08N107W. The ITCZ continues from 08N107W to 09N112W to 05N125w to beyond 02N140W. Scattered moderate isolated strong convection is noted from 04N to 07N E of 78W to the coast of Colombia. Similar convection is also seen from 06N to 10N between 104W and 109W. Scattered moderate convection is from 02N to 05N between 85W and 92W, from 04N to 07N between 120W and 125W, and from 03N to 07N between 133W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends across the offshore waters W of Baja California from a 1032 mb high centered near 34N147W to the Revillagigedo Islands. Winds and seas continue to diminish across the area as the pressure gradient relaxes between the aforementioned high pressure and a deep low pressure over interior Mexico. The most recent altimeter pass indicated seas of 8 to 12 ft N of Cabo San Lazaro. The forecast calls for mainly gentle to moderate NW to N winds during the next several days. Seas will briefly subside to 8 ft or less through tonight, but a new set of long period NW swell will propagate across the region on Sun, keeping seas of 8 ft or greater N of Punta Eugenia through early Mon. Please refer to the Special Features section for additional details concerning the late season gale-force gap wind event expected to occur over the 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 NE to E winds will prevail across the Gulf through Mon. Then, winds will increase to a fresh to strong breeze Mon night through Wed as high pressure builds N of the area. Sea heights to near 8 ft are expected 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 3 to 5 ft range through Tue, building to 4 to 6 ft Tue night through Wed night 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 ridge extends across the northern forecast waters from a 1032 mb high located near 34N147W. This system has weakened some since yesterday. As a result, winds have diminished to 20 kt or less across the waters N of 10N W OF 120W. Seas in this region are in the 8 to 11 ft range. Winds and seas will continue to 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 on Tue. This swell event will spread eastward reaching the waters W of Baja California Norte Wed night through Thu night with seas of 8 to 9 ft. Cross equatorial SW swell will bring seas to 8 ft S of 01.5S between 103W and 117W by Sun morning, and S of 01S between 112W and 120W by Mon morning. $$ GR