000 AXPZ20 KNHC 080930 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Jan 8 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Fresh to strong northerly gap winds will increase to gale force across the Gulf of Tehuantepec tonight around 0600 UTC as strong high pressure expands eastward across the Gulf of Mexico. Gale conditions will prevail through Thu night, with winds rapidly diminishing on Friday as winds in the Gulf of Mexico sharply veer to the south. Please see the latest High Seas Forecast product under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the coast of Colombia near 07N78W to 06N108W. The ITCZ continues from 06N108W to 04N140W. Scattered moderate convection is within 75 nm south of the trough axis between 84W and 91W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the offshore waters west of Baja California, producing gentle to moderate anticylonic winds. Lingering NW swell to 7-8 ft across the area will subside today. The will deflect and weaken a strong cold front approaching the region on Wed. Even though the front will dissipate prior to reaching Baja California, large long period NW swell associated with the front will sweep into offshore waters Wed night and Thu, then spread SE through Friday. Gulf of California: Moderate NW winds prevail over the central and southern Gulf, and are expected to extend to most of the Gulf of California waters through Fri morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: NE to E winds will experience diurnal pulsing, becoming fresh to strong across and downstream of the Gulf of Papagayo each night through the weekend. Gulf of Panama: Moderate to fresh northerly winds downstream to near 05N with seas to 6 ft will continue through the weekend. REMAINDER OF THE AREA... A cold front across the NW forecast waters extends from 30N134W to 25N140W. Scatterometer data this morning indicated gale force winds associated an intense low system centered well north of the area near 40N138W are N of 30N, with 25-30 kt winds depicted from 29N-30N west of 129W. Winds will diminish today the low pressure system lifts northeastward. The massive size of winds greater than gale force north of the area will generate large long period NW swell, with combined seas building to 20-25 ft NW of the front. The front will weaken and dissipate between 120W and 125W on Wed night, but the swell will continue to propagate SE into Mexican coast waters. A stronger cold front is forecast to reach the NW corner of the area on Thu morning, followed by reinforcing large long period NW swell. Strong to gale force SW winds are expected north of 29N on either side of the front Thu afternoon through early Fri. Winds will diminish on Fri, with seas to 18 ft continuing to affect northern forecast waters through early in the weekend. $$ Mundell