000 AXPZ20 KNHC 230331 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Jan 23 2017 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURE... High pressure building behind a vigorous low pressure system moving across the Gulf of Mexico will tighten the gradient in the Gulf of Tehuantepec overnight and allow winds to increase to gale force starting at 0900 UTC. The high will slide quickly eastward, and winds will diminish below gale force 12 hours later around 2100 UTC. Please see the latest East Pacific high seas forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 04N107W to 05N126W to 07N140W. No significant convection. ...DISCUSSION... ...A series of strong cold fronts and a prolonged period of unusually large swell will continue to affect most of the forecast area through Monday... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate southwest winds are ahead of a cold front west of Baja California. Large long period swell of 14 to 23 ft generated by the front will sweep east-southeastward overnight. The pressure gradient will tighten off the Jalisco Mexico coast overnight as the front approaches, briefly supporting fresh to strong winds within 120 nm of the coast. Ridging behind the front will allow fresh to locally strong north winds to spread into the southern Gulf of California to near Cabo Corrientes Monday. Strong winds sustaining the swell event will diminish by Tuesday as the high weakens, with seas decreasing below 12 ft in the offshore Mexico waters Wednesday night. However, seas of 8 to 10 ft will persist west of 100W through the end of the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds will prevail across most of the region through Tuesday. Seas will generally range between 3 and 5 ft until Tuesday, then build about a foot in response to building NW swell. REMAINDER OF THE AREA... Sscatterometer data shows strong NW winds occurring west of the front. Altimeter data shows large NW swell spreading across the waters with seas greater than 12 ft north of 20N and reaching as high as 26 ft near 30N. Large long period swell will continue to sweep southeastward with 8 ft seas reaching the equator Monday. Global models continue to show gale force winds associated with the cold front remaining just north of 30N overnight. Forecast models are in general agreement in developing low pressure over the western waters near 12N134W on Thursday and Thursday night. A large area of fresh to strong winds will be possible in the vicinity of the low from 12N to 26N W of 120W by Friday morning. $$ Mundell