000 AXPZ20 KNHC 151538 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Oct 15 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVE... A tropical wave has an axis along 103W south of 16N. The wave coincides with subtle 700 mb troughing in model fields. Scattered moderate convection is from 10N to 19N between 102W and 107W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across Costa Rica to 10N84W to 10N111W, then resumes near 16N115W and extends through 1008 mb low pressure near 15N121W to 09N135W. The ITCZ begins near 09N135W and continues beyond 09N140W. Scattered moderate and isolated strong convection are from 06N to 15N E of 100W, and from 11N to 14N between 124W and 134W. Scattered moderate convection is within 90 nm of the ITCZ axis. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pres is shifting NE away from the Gulf of Mexico, which is reducing wind funneling and pressure forcing through the Tehuantepec Gap. However, fresh to locally strong Tehuantepec winds augmented by nocturnal drainage flow will ramp up during each morning through the middle of next week. Strong high pres building in behind the next cold front could cause winds over the Gulf of Tehuantepec to increase to near gale force by next weekend. Elsewhere, a high pres ridge extends SE from a 1019 mb high center near 26N130W to near the Revillagigedo Islands at 18N110W. This ridge is generating moderate NW to N winds just W of the Baja California coast. Long period NW swell, generated by strong winds associated with a storm system north of the area, will continue advancing from the waters off Baja California Norte to the waters off Baja California Sur over the weekend. Seas currently are between 8-10 ft offshore Baja California Norte and 6 to 8 ft offshore Baja California Sur. By Sunday morning seas will continue at 8-10 ft off Baja California Norte with seas increasing to 7-9 ft offshore Baja California Sur. This swell will then persist through early next week. The high pressure ridge west of the area will intensify and build eastward Sunday night. This will result in winds increasing to as high as 25 kt along the Baja coast N of 28N from Sunday night through Monday night. Seas as high as 11 ft will be possible for these waters Tuesday night into Wednesday. This area includes forecast zone PMZ009. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW winds prevail S of the monsoon trough...including the waters between Ecuador and the Galapagos Islands. Mainly light to gentle winds continue N of the monsoon trough. Winds S of the monsoon trough may increase to moderate to locally fresh by Monday. These winds combined with cross equatorial SW swell will cause seas south of 09N to build to 6-8 ft by Monday evening...increasing to 7-9 ft west of 85W on Tuesday. REMAINDER OF THE AREA... A elongated 1008 mb low is centered near 15N121W. An area of fresh winds within 120 nm NW of the low center combined with a NW swell event have caused seas to build to 9 ft N of the low. Scattered moderate and isolated strong convection are from 10N to 17N between 116W and 124W. Some gradual development of this system is possible during the next several days as it moves WNW at around 15 mph. Long period NW swell generated by a storm system N of the area continue to spread across the waters N of 10N W of Baja California, causing seas to build to as high as 13 ft in the vicinity of 30N140W, as confirmed by an earlier altimeter pass. The long period swell will spread to N of a line from from 30N116W to 19N109W to 07N122W to 07N140W Sunday morning. A reinforcing batch of swell of 8 to 10 ft is expected to cross SE into the forecast waters from N of 30N Tuesday and Tuesday night. Expect the highest seas for all of these swell events over the NW waters. Combined NW and SW swell with moderate SW winds to the S of the monsoon trough will build an area of seas of 8-9 ft S of 10N mainly between 95W and 110W Monday through Tuesday. Additional SW swell over 8 ft will cross into the southern waters S of the equator between 95W and 120W Tuesday into Wednesday. $$ LATTO