000 AXPZ20 KNHC 251538 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1332 UTC Sun Nov 25 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 1200 UTC surface analysis and satellite imagery through 1445 UTC. ...SPECIAL FEATURE... High pressure building S along the east slopes of the Sierra Madre Occidental in Mexico on Mon will support a gap wind event over the Gulf of Tehuantepec beginning Mon evening. The winds will rapidly increase to minimal gale force right after the onset of this event with seas building to 14 ft by Tue morning. Winds and seas will then gradually diminish through Wed morning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N74W to 06N78W to 09N88W to low pressure 1008 mb centered near 08N102W to low pressure 1008 mb centered near 09.5N117W to 06N123W to 09N134W to 07N140W. Scattered moderate and isolated strong convection is found from 07N to 10N between 95W and 105W. Scattered moderate convection is present within 180 nm either side of the monsoon trough axis between 108W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A modest pressure gradient between a trough of low pressure over Mexico and surface ridging west of Baja California will maintain moderate to fresh N to NW winds W of 114W through this evening, then winds will diminish to gentle speeds. Seas of 8 to 9 ft in NW swell N of 22N will subside below 8 ft by this evening as well. A cold front will approach 30N140W by Tue night. Large long period NW swell will propagate well ahead of the front and reach the waters W of Baja California Norte by Tue morning and the southern tip of Baja California Sur by Wed morning, with seas of 8 to 12 feet in NW swell expected west of Baja through Fri. Elsewhere, low pres centered near 08N102W may lift out of the monsoon trough during the next couple of days and slowly drift NNW, eventually entering the waters S of Acapulco, Mexico near 14N104W by Wed night. This system could acquire convection and gradually develop as it tracks NNW, possibly producing fresh to strong winds and seas to 10 ft by Thu morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Enhanced infrared imagery from GOES-E continues to show a plume of volcanic ash originating from the Fuego volcano in southern Guatemala. The plume tracks WNW and becomes diffuse as it crosses into SW Mexico and nears the coast of Chiapas. The volume of ash within the plume remains light and does not warrant an ashfall advisory at this time. Gulf of Papagayo: Moderate to fresh NE winds will pulse over the area each night through Tue night. Elsewhere, the monsoon trough will meander between 05N and 10N during the next several days with gentle to moderate NE winds prevailing N of the trough, and gentle to moderate SW winds continuing S of the trough. Seas will hover between 4 to 6 ft in cross equatorial SW swell through Tue, then increase to between 5 and 8 ft S of 10N by midweek. REMAINDER OF THE AREA... The pressure gradient between 1024 mb high pressure centered near 30N134W and low pressure associated with the monsoon trough supports an area of fresh to strong NE winds over the waters from 09N to 15N west of 125W. Latest altimeter data continues to show seas of 8 to 11 ft in this region. A larger area of fresh winds in mixed NE and NW swell stretches from 08N to 22N W of 118W. Low pres centered near 09N117W is generating disorganized convection in the NW quadrant within 150 nm of its center. Fresh to strong winds are seen in the NW semicircle of the low within 90 nm with seas to 10 ft. The low will move W during the next couple of days, thus helping to maintain the area of strong winds aforementioned. Large long period NW swell associated with a strong cold front over the north central Pacific will push SE from 30N140W early on Mon, then seas will rapidly build to between 14 and 18 ft in the far NW waters by Mon night. This robust event will cause seas to build to 8 ft or above for most of the waters W of 110W by Thu morning. $$ CAM