000 AXPZ20 KNHC 190933 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jan 19 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N77W to 05N93W. The ITCZ continues from 05N93W to 03N108W to 04N140W. Scattered moderate convection is noted within 45 nm north of the axis west of 134W. ...SPECIAL FEATURES... Gulf of Tehuantepec storm warning: The next gap wind event over the Gulf of Tehuantepec is expected to commence Sat night as a strong cold front moving across the Gulf of Mexico reaches the isthmus of Tehuantepec. High pressure building behind the front will provide a very tight gradient over the area, and bring an increase in winds funneling into the Gulf of Tehuantepec. Winds will rapidly increase to gale force Sat night, and reach storm force early Sunday. Winds will diminish below storm force Sun night, then below gale force on Mon. Seas will peak near 25 ft Sunday during the period of storm force winds. Swell generated from this event will produce a large plume of 12 ft or greater seas that will extend up to 700 nm SW of the Gulf of Tehuantepec by Mon. Marine interests transiting the Gulf of Tehuantepec Sat night into early next week should be aware of this upcoming gap wind event, and take necessary action to avoid hazardous marine conditions over the affected waters. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 for further details. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features for more details on the upcoming storm force gap wind event in the Gulf of Tehuantepec. Elsewhere, moderate to fresh north to northwest winds along the offshore waters off Baja California along with long period NW swell is producing seas of 11 to 14 ft over the waters off Baja California Norte. This swell will bring dangerous surf and large breaking waves across portions of Baja California Norte through Sat. Seas in the 8 to 12 ft range prevail over the remaining open waters. Seas will slowly subside into the weekend, falling below 8 ft by late Sun night. A new set of NW swell will sweep into Baja California Norte offshore waters on Mon. This swell will spread across the remainder of the offshore waters of Baja California through the middle of next week. Gulf of California: High pressure building over the Great Basin north of the area will support fresh to strong northwest winds extending the length of the Gulf through Sat. The strength, fetch and duration of the winds will support wave heights to 8 ft in the southern Gulf of California by Sat night. Winds and seas will diminish Sun as the high weakens and shifts eastward. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The pressure gradient between high pressure north of the area and the equatorial trough will maintain strong gap winds across Papagayo and Panama through early Sat. Gap winds will diminish Sat and Sat night as high pressure north of the region shifts eastward. High pressure will build behind a strong cold front, supporting another round of stronger gap winds through the Gulfs of Papagayo and Panama. Winds to gale force are possible in the Gulf of Papagayo Sun night into Mon. REMAINDER OF THE AREA... High pressure is centered near 28N127W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh to strong trade winds north of the ITCZ, roughly south of 20N and W of 120W. The ridge will weaken Sun, allowing winds and seas to diminish across the deep tropics. Long period NW swell will continue to dominate the region, with seas 8 ft or more covering a large portion of the waters west of 105W. Seas will slowly subside into the weekend, falling below 8 ft north of 20N. South of 20N, seas of 8 to 9 ft will persist into next week from mixed northwest swell and wind waves generated by the trade winds. $$ Mundell