000 AXPZ20 KNHC 022204 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Oct 2 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 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N84W to 08N90W to 10N96W to 10N103W to 12N110W to 12N120W to 11N126W to 10N134W ITCZ axis extends from 10N134W to beyond 10N140W. Scattered moderate isolated strong convection is within 120 nm south of the axis between 121W and 125W, and within 60 nm of the axis between 131W and 134W. Scattered moderate convection is within 60 nm north of the axis between 87W and 89W, and also south of the axis within 60 nm of a line from 08N107W to 08N113W. ...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. 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 trough through 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 the 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 1030 mb centered northwest of the area 34N145W 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 13N to 23N west of 133W through Monday, and west of 127W by Tuesday. A weak surface trough extends to a low pressure of 1010 mb at 20N117W and to 17N116W. Satellite imagery shows only limited low cloudiness associated with this feature within about 90 nm either side of the low. The trough and low are forecast to gradually dissipate through Monday afternoon while moving west-southwest. $$ AGUIRRE