000 AXPZ20 KNHC 132100 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2004 UTC Fri Oct 13 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... Low pres of 1007 mb is centered near 12N110W. Scattered moderate to strong convection is noted within 120 nm southeast semicircle of the low. There is a medium probability that this low will develop into a tropical cyclone within the next 48 hours. Please refer to the latest Tropical Weather Outlook for more information. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N85W to 09N96W to 1007 mb low pressure near 12N110W to 11N117W to 12N126W to 10N140W. Scattered moderate isolated strong convection is noted north of 03N east of 84W. Scattered moderate to strong convection is noted from 10N to 13N between 107W and 112W. Scattered moderate convection is noted within 90 nm south of the monsoon trough between 120W and 124W and between 131W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends across the waters off Baja California. The pressure gradient between the ridge and a trough over the Gulf of California is supporting gentle to moderate NW winds in the offshore waters of Baja California. Seas of 4 to 7 ft prevail over the offshore waters west of the Baja California peninsula, with northerly swell just pushing into the waters north of 26N and west of 118W raising seas to 7 to 9 ft. The ridge will remain in place through Saturday will little change in winds. By Saturday evening, seas of 5-7 ft will prevail across most of the offshore waters W of 110W. High pressure across the eastern slopes of the Sierra Madre Mountains in Mexico continues to induce strong northerly gap winds across the Gulf of Tehuantepec. The strong winds over the Gulf of Tehuantepec will pulse to near gale force during the overnight and early morning hours the next couple of days. Winds will further increase to minimal gale force Monday night through early Wednesday morning as high pressure builds behind a front moving into the Gulf of Mexico. Seas downstream from the gulf will build to 8-11 ft during the times of maximum winds through Monday. Maximum seas of 12-14 ft are expected with the gale force winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh offshore winds will develop across the Papagayo region Sat and continue through Mon with seas of 5-6 ft. Light and variable winds and seas of 4 to 5 ft seas prevail N of 09N, with little change expected through Saturday morning. Seas will increase slightly through the weekend as cross-equatorial SW swell reaches the region. Gentle to moderate SW to W winds and 5 to 6 ft seas are currently observed across the area S of 09N, with a slight increase in seas expected through the weekend with the arrival of SW swell. REMAINDER OF THE AREA... Please see special features section above for more information on low pressure centered near 12N110W. Elsewhere, high pressure of 1041 mb centered NW of the area near 43N145W extends a ridge southeast to near 25N118W. The pressure gradient between the ridge and the monsoon trough is producing an area of fresh to strong NE winds northwest of a line from 30N124W to 23N140W, with seas of 8-11 ft. Winds are forecast to diminish across the northern forecast waters on Saturday as high pressure weakens and the resulting pressure gradient loosens. Seas will gradually subside, but 8-9 ft seas will continue to affect much of the area N of 20N W of 120W by Sat evening. Cross equatorial swell will continue to propagate across the waters S of 15N between 105W- 115W during the next couple of days. $$ AL