000 AXPZ20 KNHC 250305 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Dec 25 2016 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N77W to 07N86W to 06N93W. The ITCZ axis continues from 06N93W to 09N131W to 08N140W. Scattered moderate convection is from 08N to 12N between 118W and 134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Local drainage effects will continue to support fresh gap winds through the Gulf of Tehuantepec, with seas below 8 ft. Scatterometer data at 1600 UTC showed mainly 20 kt winds in this area. Model guidance indicates north winds will pulse to 20 kt during nocturnal maximum the next two days, then strong high pressure building over the western Gulf of Mexico and southern Mexico Tuesday will induce a moderate high wind event, with max winds reaching gale force early Wednesday. High pressure will persist over the Gulf of Mexico into the weekend. Persistent strong gap winds will support a plume of 8 to 14 ft seas several hundred miles from shore beginning Tuesday night. Gulf of California: Satellite imagery shows a well defined cold front sweeping across the region. Scatterometer data at 1800 UTC showed strong winds on either side of the front, with max winds to 30 kt north of 30N ahead of the front. There is enough of a fetch for seas to reach 8 ft in portions of the area. ASCAT also showed 20-25 kt NW winds behind the front. Winds will diminish overnight as the front moves east and weakens. Fresh to strong NNW winds will spread southward through Sunday as high pressure builds north of the area. Elsewhere, northwest swell associated with the cold front will increase seas to 8-12 ft off Baja California Norte and 8-10 ft seas off Baja California Sur through late Sunday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh gap winds are expected to pulse through Monday morning. Building high pressure north of the area will allow winds to increase across the Gulf of Papagayo to a fresh to strong breeze Monday night into Tuesday. Elsewhere across the region, winds will remain 20 kt or less, with seas below 8 ft through early next week. Moderate northerly winds are expected in the Gulf of Panama during the overnight and early morning hours. REMAINDER OF THE AREA... A cold front moving across northern waters extends west of Baja California from 27N114W to 21N130W. Fresh to strong NW winds and building seas up to 14 ft in NW swell associated with the front will sweep eastward east of 130W tonight and Sunday. The front will weaken as it moves further south, to extend from 25N108W to 16N121W, then as a stationary front along 16N to 137W Sunday. High pressure building eastward behind the front will support fresh to locally strong trade winds from roughly 06N to 18N west of 128W during the next 36 hours. A low pressure system moving across 30N will drag a second cold front into northern waters Sunday night with a narrow band of strong SW winds ahead of the front, and strong NW winds and building seas of 13-14 ft behind the front. More northerly swell behind the front will move into the region. The front will reach from the low near 30N124W to 25N129W to 25N140W Monday, with the low drifting southward to near 27N127W Tuesday, and a weakening occluded front extending from the low to 29N126W to 25N125W to 19N136W. Trade wind flow north of the ITCZ will weaken as the low drifts southward and the pressure gradient weakens. $$ Mundell