000 AXPZ20 KNHC 221608 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURE... A vigorous cold front will head southeastward across the Gulf of Mexico through early Monday morning. High pressure building in behind the front over the western Gulf of Mexico Monday will tighten the gradient in the Gulf of Tehuantepec tonight, thus gradually increasing the winds to gale force at 1200 UTC Monday. The high will slide quickly eastward, which will allow winds to diminish below gale force by 1800 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 06N105W to 08N130W to 05N140W. 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 the upcoming weekend... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gentle to moderate south to southeast winds are ahead of a cold front N of 24N with seas of 13 to 22 ft generated by a very large swell from the NW. Moderate to fresh N to NE winds are from 17N to 24N with seas of 8 to 12 ft. The large NW swell will continue to propagate southeastward, continuing into the deep tropics during the next several days. The pressure gradient will tighten off the Jalisco Mexico coast this afternoon as the front W of the area approaches. This will lead to NW fresh to strong winds within 120 nm off the coast increasing to near gale force Monday at 0600 UTC. 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 today. The cold front will produce a reinforcing round of large long period NW swell, which will maintain seas in the 12 to 20 foot range through Wednesday. 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... The pressure gradient between a cold front crossing the forecast area from 31N127W to 21N140W and a 1031 mb high pressure centered near 31N157W is supporting strong southwesterly winds within 210 nm ahead of the front N of 26.5N. Fresh to strong NW winds are occurring over all the forecast waters west of the front. A large NW swell event continues spreading across the waters with 12 ft seas dominating north of 21N and reaching as high as 26 ft along 29N. Seas of 8 ft or greater encompass the waters NW of a line from 19N107W to 14N110W to 04N129W 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 currently crossing the northern waters will remain just north of 30N through tonight. These winds will continue to generate NW swell. Seas of 18 to 24 ft can be expected west of the front where the near gale winds are occurring. 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. $$ Ramos