000 AXPZ20 KNHC 150904 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...TROPICAL WAVE... A tropical wave extends from 016N102W to 08N103W. Isolated moderate convection is within 120 nm of the wave axis. The wave is situated on the western edge of deep tropical moisture. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from Costa Rica at 09N84W to 11N92W to 09N103W to 15N115W to 1009 mb low pres near 15N121W to 10N132W. The ITCZ extends from 10N132W to beyond 09N140W. Scattered moderate to isolated strong convection is from 11N to 18N between 115W and 120W. Scattered moderate and isolated strong convection is N of 06N E of 83W. Scattered moderate convection is from 07N to 10N between 92W and 100W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 20-30 kt winds will pulse in the Gulf of Tehuantepec for the next 24 hours, then decrease to 20-25 kt. High pres is shifting NE away from the Gulf of Mexico, which will reduce 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 once again by next weekend. Elsewhere, a high pres ridge extending SE from a 1022 mb high near 27N129W to near the Revillagigedo Islands at 19N112W. This ridge is generating moderate NW to N winds just W of the Baja California coast, with seas ranging primarily between 5 to 7 ft. The ridge will weaken tonight as a cold front enters the far NW corner of the forecast area, but will continue to dominate the offshore waters of Baja through the upcoming weekend. Long period NW swell, generated by strong winds associated with a storm system N of the cold front will continue advancing from the waters off Baja California Norte to the waters off Baja California Sur tonight. Seas will build to between 10 and 11 ft for the waters W of Baja California N of 26N Sunday morning. A high pres ridge will build N of the area by 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 the waters adjoining the northern portion of Baja California Norte Tuesday night through Wednesday night. 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 are observed N of the monsoon trough. Seas of 4 to 6 ft S of the monsoon trough are mainly associated with long period SW swell. Winds S of the monsoon trough may increase to moderate to locally fresh by Monday. This will cause seas from 01N to 10N between 95W and 123W to build to between 8 and 9 ft by Monday evening. REMAINDER OF THE AREA... A elongated 1009 mb low is centered near 15N121W. An area of fresh winds N of the low from 15N to 18N have caused seas to build to 9 ft NE of the low within 180 nm. Scattered moderate and isolated strong convection associated with the low is seen from 11N to 17N between 118W and 122W. 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 are spreading across the NW waters, causing seas to build to as high as 12 ft in the vicinity of 30N140W. The swell was generated by a strong storm system well to the N of the area. A cold front attending this storm system has weaken considerably and is over the NW corner of our area from 30N135W to beyond 28N140W. Stronger winds behind the front will remain N of 30N. The long period swell event has seas 8ft to 12 ft across the waters N of a line from from 30N116W to 19N118W to 07N140W. The swell will spread to N of a line from from 30N116W to 20N110W to 10N120W to 10N140W by Sunday night. A reinforcing batch of swell of 8 to 10 ft is expected to cross SE into the forecast waters from 30N again on Tuesday and Tuesday night. Expect the highest seas for all of these swell events over the NW waters. $$ Formosa