000 AXPZ20 KNHC 030234 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Oct 3 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 0215 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The Monsoon Trough axis extends from 10N85W to 11N93W to 10N100W to low pressure near 11N110W 1010 mb to 11N117W to 12N124W to 10N131W to 11N140W. Scattered moderate isolated strong convection is within 180 nm north of the axis between 124W and 129W, and within 60 nm s of the axis between 133W and 139W. Scattered moderate convection is within 60 nm south of the axis between 102W and 108W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Subtropical ridge building eastward into the area has tightened the pressure gradient off the coast of Baja California Norte, and increased the north to northeast winds to 15 to 20 kt there with seas in the range of 6 to 8 ft. The pressure gradient will continue to tighten through Monday allowing for strong northwest winds to spread into the far northeast portion of the area from north of 28N to east of 119W to the coast of Baja California Norte. Northwest swell will reach south to 27N between 116W and 121W on Monday with combined seas up to 9 ft. The strong northwest winds are forecast to diminish to fresh intensity by Tuesday afternoon as the sub-tropical ridge weakens. By that time, seas of 6 to 8 ft in northwest are expected to be confined to north of 28N between 116W and 120W. Another round of northerly strong gap winds is forecast for late tonight through the isthmus of Tehuantepec, and through a narrow swath across the northern portion of the Gulf. Since the fetch of these winds will be limited with short duration time, the seas are expected to reach just under 8 ft. By early Monday afternoon, the strong winds are forecast to diminish to moderate intensity with seas of 5 to 6 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds are expected to continue north of the monsoon tonight, then become west at 10 to 15 kt Monday through Tuesday. Gentle to moderate south to southwest winds are expected to prevail south of the monsoon trough through Tuesday, with sporadic instances of these winds reaching the fresh range near convection. Wavewatch guidance suggests that seas of 4 to 6 ft in long-period southwesterly swell are expected across the offshore waters through Tuesday. REMAINDER OF THE AREA... High pressure of 1028 mb centered northwest of the area near 33N145W will slowly move south-southeast to near 33N143W by early Monday afternoon, and move little through Tuesday while weakening further. The southern periphery of the associated ridge will create a tightening gradient between it and lower pressure within the area of the monsoon trough. This will induce a large area of fresh to strong northeast to east trades north of the trough axis west of about 130W by Monday afternoon with resultant seas of 8 to 9 ft. However, a northeast swell combined with northeast wind waves will also bring seas of 8 to 9 ft outside of the area of fresh to strong trades from about 15N to 20N west of 130W through Monday evening, and from 15N to 20N west of 127W by Tuesday evening. A weak surface trough extends from 22N117W to low pressure of 1011 mb at 20N117W and to 17N116W. Satellite imagery shows only limited low cloudiness associated with this feature as it continues to move over cooler sea surface temperatures in into stable environment. The trough and low are forecast to gradually dissipate by Monday evening while moving west- southwest. $$ AGUIRRE