000 AXPZ20 KNHC 140244 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0315 UTC Fri Oct 14 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...TROPICAL WAVE... A tropical wave is along 99W S of 15N, and is located at the leading edge of an enhancement of deep tropical moisture. Scattered moderate convection is within 90 nm of either side of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the Caribbean coast of Colombia to 10N84W to 09N88W, then resumes west of a surface trough near 10N90W to 10N99W, then resumes again near 17N107W to a 1008 mb low pres near 15N115W to 10N124W to 13N137W. The ITCZ axis begins near 13N137W and extends beyond 12N140W. Outside of the tropical wave...scattered moderate convection is from 10N to 20N between 111W and 118W, and within 120 nm of either side of the monsoon trough E of 88W. Isolated moderate convection is within 120 nm of either side of the monsoon trough axis between 89W and 99W, and between 118W and 128W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Winds over the Gulf of Tehuantepec diminished below gale force earlier this afternoon. However, high pressure over and north of the Gulf of Mexico will continue to support Tehuantepec winds that will be enhanced by nocturnal drainage flow, resulting in N to NE winds near gale force tonight and through Friday morning, then winds remain mainly fresh to strong thereafter through early next week. Elsewhere, a high pressure ridge extends from the east central Pacific SE to near the Revillagigedo Islands. This ridge is supporting moderate to locally fresh northwest to north winds off the Baja California coast, with seas primarily between 5 to 7 ft. The ridge will weaken slightly on Friday as a cold front crosses the far NW corner of the forecast region, but will continue to dominate the offshore waters of Baja through the upcoming weekend. Long period northwest swell generated by a storm system northwest of the area will push into the waters off Baja California Norte later tonight and then Baja California Sur Friday night, with seas building to 8 to 10 ft by early Saturday morning. The high pressure ridge will intensify and build eastward early next week which will result in winds increasing to 25 kt with seas to 11 ft possible off the northern portion of Baja California Norte, that includes forecast zone PMZ009. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate southwest winds persist south of the monsoon trough and a surface trough...including the waters between Ecuador and the Galapagos Islands. Mainly light to gentle winds are north of the monsoon trough. Seas are 4 to 6 ft south of the monsoon trough are mainly associated with long period southwest swell. These marine conditions will change little over the next few days. Isolated to scattered moderate convection will persist within 120 nm of the monsoon trough axis through at least Friday. REMAINDER OF THE AREA... A broad area of low pressure is located near 15N115W with an estimated central pressure of 1008 mb. Earlier today this system was found to not have a completely closed center of circulation. Fresh to locally strong winds are within about 90 nm N semicircle of the low center with seas to 8 ft. Some slow development of this disturbance is possible during the next several days while it moves west-northwestward at around 15 mph. Another low pressure system is centered near 19N133W with an estimated minimum pressure of 1014 mb. Fresh to strong winds are within about 150 nm over the northern semicircle of the low. These winds are mainly the result of the pressure gradient between the low and a ridge to the N. The low is currently moving over cooler water. This along with increasing wind shear aloft has limited the associated shower and thunderstorm activity near the low center. Further development is therefore not anticipated. However, fresh to strong winds may persist on the northern semicircle of the low center through Friday night as it continues to move westward. Long period NW swell with seas up to 12 ft is beginning to propagate across the NW waters. This swell has been generated by a storm system well to the north. A cold front associated with this storm system front will weaken considerably by the time it reaches the NW corner of our area tonight, with stronger winds remaining north of 30N. This long period swell event will bring seas of 8 to 12 ft across the waters NW of a line from 30N119W to 16N128W to 11N140W by Friday afternoon, and across the forecast region NW of a line from 29N115W to 22N113W to 08N125W to 05N140W by Saturday afternoon. The 8 to 12 ft swell is expected dominate most of the forecast waters N of 10N W of 110N by Sunday morning. Expect the highest seas over the NW waters. $$ LATTO