000 AXPZ20 KNHC 112158 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Oct 11 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... A gale warning remains in effect for the Gulf of Tehuantepec. Winds in this area are in the 30-35 kt range based on a pair of ship observations and an earlier Ascat pass. Seas are 9 to 12 ft. A tight pressure gradient continues between 1020 mb high pressure centered over east-central Mexico and a 1008 mb surface low located in the eastern Pacific near 11N103W. The surface pressure gradient will slacken and winds will diminish slightly wed evening. Strong gap winds will continue through Friday however, mainly during the overnight and early morning hours with winds reaching 30 kt. Seas are forecast to subside to 8 to 11 ft. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W TO 11N95W TO 1008 mb low near 11N103W to 11N110W to 15N116W. The monsoon trough resumes from 14N126W to 1008 mb low near 11N130W to 08N138W. The ITCZ extends from 08N138W to beyond 08N140W. Scattered moderate convection is N OF 05N E OF 86W. Scattered moderate to isolatedstrong convection is from 09N TO 16N between 95W and 110W. Scattered moderate convection is from 10N TO 20N between 120W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak 1021 mb high pressure located near 30N130W extends a ridge SE across the Pacific waters of Baja California peninsula, producing mainly light to gentle NW-N winds with seas of 4-6 ft. As the subtropical ridge strengthens...expect increasing winds to 15-20 kt and building seas to around 7 ft off the coast of the Baja California peninsula by Wednesday. Elsewhere light to gentle winds, and 3 to 5 ft seas will persist. 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 through...including the waters between Ecuador and the Galapagos Islands. Seas are 4 to 6 ft south of the monsoon trough largely associated with long period southwest swell. These marine conditions will change little over the next few days. Scatterometer data indicate moderate to fresh NE winds across the Gulf of Papagayo. This weather pattern will persist over the next 2-3 days. REMAINDER OF THE AREA... As previously mentioned...a weak 1021 mb high pressure located near 30N130W extends a ridge SE across the north waters to near the Revillagigedo Islands. The ridge is forecast to slightly strengthen on Wednesday. A surface trough is analyzed across the NW waters and extends from 30N135W to 23N140W. A 75-90 nm wide band of mainly low clouds is still noted is association with this trough forecast to gradually dissipate by late Wednesday. Seas to 9 ft in NW swell are noted per an altimeter pass in the wake of the frontal trough. Another set of NW swell should reach the far NW portion on Wednesday. This swell event will dominate the waters NW of a line from 30N133W to 20N138W by early Thursday morning with seas building to near 12 ft. An area of moderate to fresh trade winds persists between the ridge to the north and a 1007 mb low pressure located near 17N123W covering roughly the region from 12N to 21N between 118W and 127W. These winds are expected to persist over the next 48 hours as the low pressure continues to move west-northwestward. Showers and thunderstorms associated with this feature have become a little more concentrated this morning. A cluster of moderate to isolated strong convection is noted within about 150 nm NW quadrant of low center. This disturbance has the potential to become a tropical depression before it moves over cooler waters in 2 or 3 days. Another low pressure area is noted downstream from the Gulf of Tehuantepec near 11N103W. Disorganized showers and thunderstorms are associated with this weak low pressure system. Environmental conditions are expected to be generally conducive for development, and a tropical depression could form by the weekend while the low moves westward well to the southwest of mainland Mexico. An area of fresh to strong winds is observed is association with this low from 11N to 13N between 97.5W and 102W with seas of 8 to 10 ft. $$ Formosa