000 AXPZ20 KNHC 170719 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... A gale warning remains in effect for the Gulf of Tehuantepec. Minimal gale force winds of 30-35 kt are still expected early this morning across the Tehuantepec region, then winds will diminish below gale force by late this morning. Seas of 10-14 ft will gradually subside to 8-11 ft by early this 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 early this afternoon. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. Currently, marine guidance suggests another gap wind event, with minimal gale force winds, across the Gulf of Tehuantepec by late Thu as a strong high pressure builds southward across the central plains of U.S. and the Gulf of Mexico. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N77W to 08N84W to 05N90W. The ITCZ stretches from 05N90W to 08N108W to 07N120W to beyond 08N140W. Scattered moderate to isolated strong convection is from 05N to 07N E of 79W to the coast of Colombia. Scattered moderate convection is noted from 05N to 10N between 120W and 125W. Similar convection is also seen from 12N to 14N between 110W and 112W. ...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