000 AXPZ20 KNHC 202034 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Feb 20 2024 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 2000 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over the Gulf of Mexico and the eastern north Pacific equatorial trough is supporting gale force N gap winds over the Gulf of Tehuantepec, with seas peaking near 11 ft. The area of high pressure will start to weaken and shift E tonight. This will loosen the pressure gradient, and diminish winds below gale force early Wed. The area of high pressure will then continue to weaken and move further from the area, loosening the pressure gradient and veering winds over the SW Gulf. This will diminish winds to 20 kt or less by Thu morning. Gulf of Papagayo Gale Warning: The pressure gradient between high pressure over the Gulf of Mexico and low pressure within the eastern north Pacific equatorial trough is supporting fresh to strong winds over and downstream the Gulf of Papagayo, with occasional near- gale force winds closer to the Gulf. Winds will briefly pulse to minimal gale force in the Gulf late Wed night into early Thu morning with the added component of nocturnal drainage flow. As the area of high pressure weakens and moves further from the area, the pressure gradient will loosen and winds will diminish Fri and Fri night. Winds will strengthen again over the Gulf of Papagayo region on Sat as high pressure once again builds N of the area. Large NW Swell: Subsiding NW swell prevails across the northern waters. This afternoon, seas greater than 12 ft cover the waters N of 23N between 116W and 130W, and N of 25N between 130W and 140W, and are peaking near 13 ft. Seas will subside below 12 ft this evening. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The equatorial trough extends from 08N78W to 04N101W. The ITCZ continues from 04N101W to 04N117W to 01N140W. Scattered moderate and isolated strong convection is noted from 00N to 06N between 78W and 121W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section above for information about a Tehuantepec Gale Warning and the large NW swell. Aside from the Gulf of Tehuantepec, a weak pressure gradient prevails across the forecast waters. This loose gradient is supporting gentle to locally moderate winds off the Baja California peninsula and the Gulf of California. Light winds are noted elsewhere. Aside from the seas greater than 12 ft discussed above, seas 8 ft or greater cover the waters N of the Revillagigedo Islands. Seas of 6-7 ft are over the waters off SW Mexico, and 3 ft or less over the Gulf of California. For the forecast aside from the Gulf of Tehuantepec gales, winds should generally remain moderate or weaker for the next several days over the Mexican offshore waters. Large, long- period WNW swell will impact the waters west of Baja California to the Revillagigedo Islands through Wed night. Looking ahead, the next Gulf of Tehuantepec gap wind event should begin Fri night, with winds currently forecast to peak at near- gale force speeds Fri night through Sat night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR Please read the Special Features section above for information about a Gale Warning in the Gulf of Papagayo. Fresh to strong gap winds, and seas of 8-9 ft, are over and downstream the Gulf of Papagayo. Fresh to locally strong winds are over and downstream the Gulf of Panama. Seas of 7-8 ft are well offshore Guatemala and El Salvador. Elsewhere, seas of 4-6 ft elsewhere. For the forecast aside from the Gulf of Papagayo gales, fresh to occasionally strong N to NE winds will prevail over the Gulf of Panama through Thu night before diminishing on Fri. Large NW swell generated from a gale force gap wind event in the Gulf of Tehuantepec will impact the outer waters of Guatemala and El Salvador through Wed. ...REMAINDER OF THE AREA... Please read the Special Features section above for information about an ongoing large NW swell. A surface trough extends from 30N128W to 22N128W. A 1029 mb high is centered WNW of the area near 27N149W, with ridge extending SE to near 23N130W. The pressure gradient between this area of high pressure and the trough is supporting moderate to locally fresh winds over the waters N of 24N and W of 128W. The pressure gradient between the area of high pressure and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh trades N of the ITCZ and W of 130W. A weak 1022 mb high is centered near 21N119W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting moderate trades N of the ITCZ to near 11N between 100W and 130W. Light to gentle winds are in the vicinity of the weak high center. Gentle winds prevail elsewhere. Outside of the seas greater than 12 ft, seas 8 ft or greater cover much of the waters W of 105W. For the forecast, high pressure will build into the NW waters in the wake of the trough on Wed and Thu. This will tighten the pressure gradient, and bring a slight increase to the trades N of the ITCZ and west of 120W. Areal coverage of seas greater than 8 ft will gradually start to decrease late Wed as the NW swell decays. On Fri into the weekend, an extratropical low will move slowly eastward along the 30N border, bringing strong to near gale N winds in its W semicircle. On Fri, a new set of very large NW swell associated with the extratropical low will propagate into the NW waters. $$ AL