000 AXPZ20 KNHC 160922 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Apr 16 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. A recent scatterometer pass provided observations of 35-45 kt across the Tehuantepec region and downwind to near 13N while an altimeter pass indicated seas to around 16 ft near 13.5N95.5W. Gale force winds of 30-40 kt are forecast to persist today and tonight while gradually diminishing to 30-35 ft by early Tue morning. Seas are expected to further build to 18-20 ft by this morning, then will begin to gradually subside to 10-15 ft by tonight. An extensive swath of large N to NE swell generated by these northerly winds will continue to propagate well to the SW of the Tehuantepec area, covering roughly the waters from 08N to 15N between 93W and 105W by this afternoon. This has been a strong late season Gulf of Tehuantepec gap wind event. Winds are forecast to be below gale force by late Tue morning. 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 07N78W to 09N90W to 08N100W. The ITCZ stretches from 08N100W to 06N120W to 06N140W. Scattered moderate convection is from 05N to 08N between 114W and 117W. Similar convection is also noted from 10N to 12N between 95W and 100W, from 11n to 14N between 105W and 108W, and from 11N to 13N between 110W and 111W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to fresh NW to N winds will prevail across the offshore waters W of Baja California, and mainly N of Cabo San Lazaro during the next several days. 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 or Sea of Cortez. Seas will remain in the 8-10 ft range across the offshore waters through mid-week. Gulf of California: Moderate to fresh southerly winds will further 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 winds are forecast across the remainder of the Gulf much of the forecast period. 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 overnight and early morning hours through Fri. Gulf of Panama: Moderate to fresh northerly winds are expected across the Gulf of Panama at night, begining 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. REMAINDER OF THE AREA... A cold front has entered the NW corner of the forecast region and extends from 30N126W to 27N140W. Mainly low clouds are associated with the frontal boundary. The front will weaken across the northern forecast waters today. Fresh to locally strong N to NE winds follow the front. A strong high pressure of 1038 mb in the wake of the front will move SE bringing fresh to strong NE-E winds across the waters from 19N to 27N W of 130W by this afternoon. Large NW swell continues to propagate southeastward through the forecast waters, with max seas of around 12 ft in the far western waters N of the ITCZ. This swell event will mix with waves generating in the Tehuantepec area this morning. As a result, seas of 8 ft or greater will cover much of the forecast region W of 108W today. Cross equatorial SW swell are 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 07N between 96W and 120W by early Tue evening. $$ GR