000 AXPZ20 KNHC 272135 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Jan 27 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 1800 UTC surface analysis and satellite imagery through 2045 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Weakening high pressure over the Gulf of Mexico and eastern Mexico is supporting a moderate pressure gradient across the Isthmus and Gulf of Tehuantepec this afternoon. Nly winds have diminished to 20-25 kt across and just downwind of Tehuantepec this afternoon, where seas have subsided to 8-10 ft. A new cold front will move across the Gulf of Mexico tonight through Mon. High pressure building in the wake of the front will help to re-initiate gales across Tehuantepec by Sun morning, and increase to strong gales Sun night. 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 10N74.5W TO 09.5N84W TO 05N91W. The ITCZ continues from 05N91W to 07N121W TO beyond 09N140W. Scattered moderate to strong convection is noted within 120 nm of the ITCZ between 110W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Please refer to the special features section above for more on the latest, and next expected, gale force gap wind event. Looking ahead, winds associated with the next gale force gap wind event starting early Sun are expected to increase to strong gales Sunday night, and further increase to storm force Mon evening through Tue as strong high pressure moves over the SE U.S. Gulf of California: Winds have strengthened to around 20 kt across all but south portions of the gulf this afternoon and are expected to increase slightly to 20-25 kt this evening due to high pressure building over the Great Basin region. Computer models suggest this pattern will persist through Sun, with the potential for small areas of winds to 30 kt Sun morning through Mon morning, mainly N of 29N. Peak seas are expected to gradually build to 9 ft early Sun. NW swell will continue to propagate across the waters off the coast of Baja California Norte. Seas associated with this swell peaked near 12 ft yesterday evening, and are subsiding very slowly today, with latest observations suggesting seas of 8-11 ft. Seas west of the Baja Peninsula will subside below 8 ft by early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... persistent moderate to fresh gap winds will pulse to strong the next several nights over the Gulf of Papagayo. Elsewhere N of 09N, gentle to moderate offshore flow will prevail through Mon. Gentle to moderate S to SW winds will prevail S of 09N the next few days. REMAINDER OF THE AREA... High pressure of 1032 mb is near stationary north of the area near 35N127W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ to the S is supporting fresh to strong trades from 07N to 21N and W of 116W, where seas are 9 to 13 ft. NW swell also continues to propagate across these waters and is mixing with the wind generated NE waves. Seas 8 ft or greater associated with this swell cover much of the forecast waters west of 113W. The area of high pressure will remain north of the area through the weekend, helping to maintain this area of fresh to strong trades, and will combine with the NW swell to keep seas in the 8 to 11 ft range through early Mon. $$ Stripling