000 AXPZ20 KNHC 191544 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1428 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...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. Gulf of Papagayo Gale Warning: 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 expected in the Gulf of Papagayo Sun night into Mon with seas building up to 14 ft by late Mon morning. At the same time, expect fresh to strong winds across the Gulf of Fonseca and downstream to 90W. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from a 1010 mb low pressure located over Colombia near 08N75W to 05N79W to 07N85W to 04N95W. The ITCZ continues from 04N95W to 03N110W to 05N135W to 04N140W. Scattered moderate convection is noted from 04N to 06N W of 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please, see special features for more details on the upcoming storm force gap wind event in the Gulf of Tehuantepec. A Storm Warning is in effect. Elsewhere, moderate to fresh north to northwest winds along the offshore waters off Baja California combined with long period NW swell is producing seas of 10 to 14 ft over the waters off Baja California. This swell event will bring dangerous surf and large breaking waves across portions of Baja California through today. Seas will slowly subside this weekend, falling below 8 ft by late Sun night. A new set of NW swell, with seas in the 8 to 11 ft range, 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 over the Great Basin north of the area is supporting fresh to strong northwest winds across the entire Gulf. The strength, fetch and duration of the winds will support wave heights to 8 ft in the southern Gulf of California today. Winds and seas will diminish on 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 Sun. High pressure will build behind a strong cold front, supporting another round of stronger gap winds through the Gulfs of Papagayo, Panama and Fonseca. A Gale Warning has been issued for the Gulf of Papagayo with this forecast package. Please, see special features for more details. REMAINDER OF THE AREA... High pressure of 1026 mb is centered near 33N124W. 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 some 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 tonight into Sun, falling below 8 ft north of 25N by early Sun morning. South of 25N, seas of 8 to 10 ft will persist into next week from mixed northwest swell and wind waves generated by the trade winds. A nearly stationary front has reached 30N140W. The front will drift SE across the NW corner of the area through Sun while dissipating S of 30N. High pressure in the wake of the front will bring increasing winds and building seas across the west- central waters, and also over the offshore waters of Baja California, mainly N of Punta Eugenia on Mon. $$ GR