000 AXPZ20 KNHC 122200 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2200 UTC Tue Dec 12 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A tight pressure gradient continues across the Isthmus of Tehuantepec in southern Mexico. Latest scatterometer data indicate winds just reaching gale force over the Gulf of Tehuantepec. High pressure north of the area will shift eastward and weaken. This will loosen the pressure gradient over the area and help to diminish winds below gale force by Wednesday night, and further to 20 kt or less Thursday. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N82W to 04N90W to 04N92W. The ITCZ continues from 04N92W to 10N127W to 08N140W. Scattered moderate and isolated strong convection are from 09N to 14N between 120W and 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Please see Special Features section above for details on the ongoing gale event. Fresh to locally strong NW winds will prevail over the northern part of the Gulf of California through tonight. Mainly moderate NW-N winds will prevail elsewhere over the offshore Pacific waters, with seas in the 4-6 ft range. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR...Corrected Strong winds will prevail across the Gulf of Papagayo through Thu before diminishing. Winds will once again strengthen Sat. Moderate to fresh N winds will funnel through the Gulf of Panama Thu and Fri, becoming moderate Sat. REMAINDER OF THE AREA... The pressure gradient between high pressure centered north of the area and lower pressure in the vicinity of the ITCZ is maintaining an area of fresh to strong winds from 12N to 17N between 130W and 135W. The area of high pressure will weaken over the next 24 hours which will help loosen the pressure gradient and diminish winds to 20 kt or less by Wednesday. NW swell covers much of the forecast waters west of 120W and north of 06N. A fresh set of NW swell has reached the NW waters. Seas associated to this swell will peak near 13 ft tonight and Wednesday morning before starting to subside. $$ AL