000 AXPZ20 KNHC 250320 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0320 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...SPECIAL FEATURE... High pressure building over eastern Mexico early this coming week will support a Gulf of Tehuantepec gap wind event beginning Mon evening. The winds will rapidly increase to minimal gale force right after the onset of this event with seas building to 13 ft by Tue morning. Winds and seas will generally diminish late Tue morning through Thu night, but winds will pulse stronger at night in response to nocturnal drainage. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 06N78W to 09N90W to low pres of 1006 mb near 08N100W to low pres of 1008 mb near 09N117W to 09N140W. Scattered moderate and isolated strong convection is present from 08N to 10N between 96W and 99W and from 05N to 12N between 113W and 120W. Isolated moderate convection is from 04N to 11N W of 120W. ...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 112W through early Sun, then winds will diminish to gentle speeds. Seas of 8 to 9 ft in NW swell N of 25N will subside below 8 ft by Sun evening. A cold front will approach 30N140W by Tue evening. Large long period swell will propagate well ahead of the front and reach the waters W of Baja California Norte by Tue evening and the southern tip of Baja California Sur by Wed night, with seas of 8 to 13 feet in NW swell expected west of Baja through Thu night. Elsewhere, low pres near 08N100W may break away from the monsoon trough over the next couple of days and slowly drift NNW, eventually entering the waters S of Acapulco, Mexico near 13N103W 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 shows a plume of volcanic ash originating from the Fuego volcano in southern Guatemala. The plume becomes diffuse as it nears the coast of Guatemala. 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 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 5 to 8 ft S of 10N by midweek. REMAINDER OF THE AREA... The pressure gradient between 1026 mb high pressure centered near 30N136W and the ITCZ supports an area of fresh to strong NE winds over the waters from 10N to 14N between 131W and 138W. Recent altimeter data continues to show 8 to 11 ft seas within this region. Surface low pres will develop near 08N135W by Sun morning, then weaken as it heads W. The low will help to maintain the area of strong winds in this region as it slowly moves W, then winds will slowly diminish as the low weakens through Mon. 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. $$ Latto