000 AXPZ20 KNHC 220800 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 713 UTC Sun Jan 22 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURE... High pressure building in behind a vigorous cold front in the southwestern Gulf of Mexico Monday will induce gale force winds over the Gulf of Tehuantepec beginning around 0900 UTC Monday morning. The high will slide quickly eastward, which will allow winds to diminish below gale force by Monday afternoon. 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 06N99W to 07N109W to 05N124W to 07N134W to 07N140W. No significant convection. ...DISCUSSION... ...A series of strong cold fronts and a prolonged period of unusually large swell will affect most of the forecast area... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong northwest winds and seas of 12-22 ft are affecting waters north of 24N. Large northwest swell will continue to propagate southeastward, continuing into the deep tropics during the next several days. Seas will build to 20 ft off Baja California Norte overnight, and the leading edge of high seas will reach Socorro Island late Sunday morning. Ridging behind the front will allow fresh to locally strong north winds to spread into the southern Gulf of California to near Cabo Corrientes late Sunday. Another cold front will produce a reinforcing set of large long period NW swell, which will maintain seas in the 12 to 20 foot range through Tuesday. Strong winds sustaining the swell event will diminish by Tuesday as the high weakens, with seas decreasing below 12 ft in offshore Mexico waters Wednesday night. However, seas of 8 to 10 ft will remain west of 100W through the end of the week. High pressure building in behind a strong cold front in the Gulf of Mexico will increase the pressure gradient across the Isthmus of Tehuantepec and cause gap winds to increase to gale force over the Gulf of Tehuantepec Monday morning. Please see the special features section for more details. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle southeast to east winds will prevail across most of the region through Tuesday. Seas will be generally 3-5 ft in the forecast waters. Fresh to strong gap winds will pulse in the Gulfs of Papagayo and Panama Tuesday night and Wednesday night as high pressure passes north of the Caribbean basin. REMAINDER OF THE AREA... The pressure gradient between a cold front approaching southern California and high pressure centered near 25N120W supporting strong northwesterly winds across northern waters west of 128W. A large northwesterly swell event is spreading across the waters with 12 ft seas dominating north of 21N and reaching as high as 26 ft along 30N. Seas of 8 ft or greater extend northwest of a line from 22N109W to 17N109W to 04N140W. Large long period swell will continue to sweep southeastward with 8 ft seas nearing the equator early Monday. Global models continue to show gale force winds associated with the cold front moving across the northern waters remaining just north of 30N through Sunday night. These winds will help to re-enforce the northwest swell with seas of 18 to 23 ft west of the front where the near gale winds are occurring. Mainly gentle to moderate winds will prevail elsewhere, with 4-7 ft seas expected through Monday. NE swell from the Tehuantepec high wind event will increase seas to 8-10 ft Monday night. $$ cam