000 AXPZ20 KNHC 142128 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1914 UTC Sat Oct 14 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: Strong winds prevail over the Gulf of Tehuantepec. Winds will pulse to near gale force overnight with the added component of nocturnal drainage flow. High pressure building over eastern Mexico in the wake of a cold front moving across the Gulf of Mexico will tighten the pressure gradient over the region. This will increase gap winds funneling through the Chivela pass into the Gulf of Tehuantepec. Winds will reach minimal gale force early Monday morning, and continue through at least midweek. Seas will reach 13-15 ft during the overnight hours of this event, when winds will peak near 40 kt. Low pressure of 1007 mb is embedded within the monsoon trough near 14N113.5W. Scattered showers and isolated thunderstorms associated to this feature are noted from 09N to 15N between 111W and 120W. There is currently a high probability that this low will develop into a tropical cyclone over the next 48 hours. Please refer to the latest Tropical Weather Outlook for more information. ...TROPICAL WAVES... The axis of a tropical wave axis analyzed near 86W N of 04N, moving westward near 17 kt. Scattered moderate convection is noted over the southern portion of the wave from 06N to 08N within 30 nm of the trough axis. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N97W to 09N93W to low pres near 14N113.5W to low pres near 10N130W to 09N135W. The ITCZ extends from 09N135W to 09N140W. Scattered moderate convection was noted from 06N to 09N between 81W and 87W. Scattered moderate isolated strong convection was noted from 09N to 13N between 91W and 94W. Scattered moderate isolated strong convection was noted from 09N to 15N between 111W and 120W. Scattered moderate convection was noted from 10N to 12N between 125W and 131W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends across the waters off Baja California. Outside of the Gulf of Tehuantepec, gentle to moderate winds prevail over the open forecast waters with light winds over the Gulf of California. Seas are in the 6-7 ft range over the open waters, and 1-3 ft over the Gulf of California. The ridge will remain in place this weekend with little change in winds. High pressure building over the Great Basin region will help to strengthen winds over the northern Gulf of California early Sunday, and continue through early in the week. The area of high pressure will then shift eastward which will help to decrease winds over this area. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh offshore winds will prevail across the Papagayo region through midweek with seas of 5-7 ft. Light and variable winds and seas of 4 to 5 ft seas prevail elsewhere N of 09N. Gentle to moderate SW to W winds and 5 to 7 ft seas will prevail across the waters S of 09N through early next week before seas subside to 3-5 ft by midweek. REMAINDER OF THE AREA... Please see special features section above for more information on low pressure centered near 14N113.5W. Elsewhere, high pressure of 1039 mb centered NW of the area near 41N145W extends a ridge southeast to near 25N117W. The pressure gradient has relaxed slightly over the forecast waters, with strong winds now limited to the area from 21N to 24N west of 130W. Northerly swell continue to propagate across the waters, with seas of 8 to 11 ft west of a line from 30N119W to 20N127W to 12N127W. The pressure gradient will continue to loosen, with winds diminishing to 20 kt or less by Sunday. The swell will also subside, with seas of 8 to 9 ft confined to the waters from 10N to 15N west of 132W by early next week. Cross equatorial southwesterly swell will continue to propagate across the south- central waters, particularly S of 15N between 100W- 120W over the next couple of days. $$ AL