000 AXPZ20 KNHC 290909 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 529 UTC Mon Jan 29 2018 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 Storm Warning: High pressure building in the wake of a cold front in the Gulf of Mexico has tightened the pressure gradient over the area. This has increased northerly winds to gale force across Tehuantepec. Winds will reach storm force this evening through Tue. The area of high pressure dominating the Gulf of Mexico will then start to shift eastward, gradually loosening the pressure gradient. Winds will diminish to gale force Wed, and fall below gale force on Thu. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N77W to 06N82W to 06N94W. The ITCZ continues from 06N94W to 07N104W to 07N120W to beyond 10N140W. Scattered moderate isolated strong convection is noted from 05N to 08N between 100W and 115W. Scattered moderate isolated strong convection was noted within 30 nm S of the ITCZ W of 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Please refer to the special features section above for more on the latest gap wind event. As the winds increase from gale to storm force across Tehuantepec late tonight through Tue, a large and broad wind field will extend well to the SW of the Mexican coastline, to near 09N101W by Tue morning. This will generate a very large area of 10 to 20 plus ft seas in N to NE swell across this area. Gulf of California: Winds of 20-30 kt prevail over the N portion of the Gulf of California. Winds will diminish to 20 kt or less by this evening. Elsewhere over the open waters, seas are expected to remain at or below 6 ft through Fri as a tranquil pattern prevails. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong gap winds will increase to near gale force Tue night and Wed over the Gulf of Papagayo. Elsewhere N of 09N, gentle to moderate offshore flow will strengthen Tue through Wed. Gentle to moderate S to SW winds will prevail S of 09N the next few days. REMAINDER OF THE AREA... High pressure of 1028 mb is centered north of the area near 38N127W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh to strong trades from 09N to 17N W of 130W, where seas are 9 to 12 ft. The area of high pressure will weaken the next couple of days. This will decrease areal coverage of the fresh to strong trades, with winds diminishing to 20 kt or less by late tonight, with seas gradually subsiding to 6-8 ft across the trade wind belt by midweek. Large swell generated from the latest Gulf of Tehuantepec gap wind event will propagate across the waters south of 14N and east of 120W through the week while subsiding. $$ AL