000 AXPZ20 KNHC 170233 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Apr 17 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... A gale warning remains in effect for the Gulf of Tehuantepec. Northerly winds of 30-40 kt are still expected tonight across the Tehuantepec region, diminishing to 30-35 kt by early Tue morning, and below gale force by late Tue morning. Seas of 10-14 ft will gradually subside to 8-11 ft by early Tue afternoon. An extensive swath of large N to NE swell generated by this gap wind event will continue to propagate well to the SW of the Tehuantepec area, covering roughly the waters from 03N to 14N between 93W and 110W by Tue afternoon. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N78W to 08N83W to 05N90W. The ITCZ stretches from 05N90W to 08N108W to beyond 07N140W. Scattered moderate convection is noted within 60 nm S of the axis between 103W and 111W. Similar convection is from 05N to 08N between 118W and 122W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gentle to moderate NW to N winds prevail across the offshore waters W of Baja California, with strongest winds N of Punta Eugenia. Winds will briefly increase to 20-25 kt mainly N of 28N and E of 118W tonight as a weakening cold front moves across the northern Baja California peninsula and the northern Gulf of California. Seas will remain in the 8-10 ft range across the offshore waters through mid-week. Gulf of California: Moderate southerly winds across much of the Gulf are freshening across N portions this evening, and will increase to 20-25 kt across the northern Gulf of California ahead of a cold front crossing the area tonight. Then, fresh to strong NW-N winds are expected behind the cold front early on Tue. Gentle to moderate NW winds are then expected to prevail across the Gulf Wed through Fri. Gulf of Tehuantepec: A strong late season Gulf of Tehuantepec gap wind event was induced by a strong cold front moving across the Gulf of Mexico during the previous days. Please, see Special Features section above for details. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Pulsing fresh to strong NE-E winds are expected across and downstream of the Gulf of Papagayo during the late afternoon through early morning hours each day through Fri. Gulf of Panama: Moderate to fresh northerly winds are expected across the Gulf of Panama at night, beginning tonight through Wed night. Elsewhere, light to gentle winds are expected through the forecast period, with a weak surface through extending along 08- 09N yielding light S to SW winds to its south. Seas in the 3 to 5 ft range will continue over most of the area. Cross equatorial SW swell will mix with residual swell from Papgayo Tue night through Fri and raise seas to 5-7 ft S of 10N. REMAINDER OF THE AREA... A cold front is moving SE across the northern Baja California peninsula and extends from the California-Mexico border near 32N115W to beyond 29N118W. The front will continue to move SE across the NE waters E of 120W tonight and gradually weaken. Fresh to locally strong N to NE winds follow the front. A 1031 mb high pressure center located near 35N140W behind the front will move SE bringing fresh to strong NE-E winds across the waters W of 125W tonight. Large NW swell continues to propagate southeastward through the forecast waters, with max seas of around 11 ft in the far western waters N of the ITCZ. This swell event is mixing with waves generating in the Tehuantepec area. As a result, seas of 8 ft or greater will cover most of the area W of 110W on Tue. Cross equatorial SW swell is forecast to reach the southern forecast waters by Tue morning. Marine guidance suggests that seas of 8-9 ft will dominate the waters S of 04N between 97W and 120W by early Tue evening. $$ GR