000 AXPZ20 KNHC 300002 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 2205 UTC Thu Sep 29 2016 Corrected header time 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. ...SPECIAL FEATURES... Tropical Storm Ulika is centered near 17.2N 140.2W 1006 mb, or about 860 nm east of Hilo Hawaii, at 2100 UTC moving NW or 305 DEG at 7 kt. The maximum sustained wind speed is 35 kt with gusts to 45 kt. Ulika remains under significant vertical westerly shear attributed to an upper trough that is just to its west. Abundant dry air aloft west of the trough is being entrained into the cyclone as observed in water vapor imagery. Latest satellite imagery shows diminishing scattered moderate convection well removed from the cyclone between 60 nm to 120 nm to its northeast. Minimal tropical storm winds are within 30 nm in the east semicircle and 20 nm in the northwest quadrant of the cyclone. Ulika continues to experience SW wind shear and is forecast to weaken to a tropical depression late tonight west of the area near 17.7N 141.W, and a post-tropical remnant low early Friday afternoon near 18.3N 142.9W. Refer to the latest CPHC forecast/advisory under AWIPS/WMO headers WTPA22 PHFO/TCMCP2, or visit the CPHC website at http:www.prh.noaa.gov/cphc/ for additional details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwest Colombia to 10N85W to 09N94W to 12N107W where it ends. It resumes at 10N116W to 09N124W to 14N135W. Scattered moderate to isolated strong convection is seen within 120 nm north of the axis between 91W and 94W. Scattered moderate convection is within 60 nm s of the axis between 103W and 108W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Post-tropical remnant low of Roslyn is centered near 24.1N 115.6W 1014 mb moving N NW at 6 kt. Visible satellite imagery depicts the low as a cloud swirl consisting of mainly low clouds about 120 nm in diameter. Associated winds continue to diminish with only 20 to 25 kt with seas of 6 to 8 ft remaining within 30 nm of the low in the northeast quadrant of the low. The low is forecast to gradually dissipate through Friday afternoon. Otherwise, a sub-tropical northwest to southeast oriented ridge axis extends into the area from 32N136W to near 24N131W. High pressure covers the area north of 22N west of 123W. Light to gentle northerly winds are present west of the Baja California Peninsula with seas of 4 to 5 ft in mixed NW and SW swell. The ridge will strengthen and build southeastward through the next 48 hours. The associated gradient is expected to result in a moderate to fresh northwest flow. Seas will build to 6 to 8 ft over the far northern waters west of Baja California Norte on Saturday evening, and continue into Sunday. Light and variable winds are expected through the weekend across the northern Gulf of California, and light to gentle nw-n flow is expected elsewhere. Winds will increase through mid week as the ridge builds into the region. A high amplitude surface trough analyzed along 108W from 13N to 22N is forecast to drift westward over the next couple of days. Deep convection continues to be very active in an inverted-v shape pattern. The convection is of the scattered strong type intensity from 13N to 22N between the trough and 112W. Scattered moderate to isolated strong convection is noted from 14N to 18N between 102W and 106W. Scattered moderate convection is from 09N to 13N between 112W and 114W. Fresh to strong drainage flow that occurred through the Gulf of Tehuantepec in the overnight hours will again pulse up and down through the weekend, peaking to the range of 25 to 30 kt with seas of 8-10 ft late at night and through daybreak. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle southerly winds are expected n of the monsoon trough, while gentle to locally moderate s to SW flow is expected s of the monsoon trough through the upcoming weekend. Combined seas of 4 to 7 ft, primarily in long-period SW swell is expected across the offshore waters through the upcoming weekend. REMAINDER OF THE AREA... As tropical cyclone Ulika moves w of 140W tonight and the remnant low of Roslyn dissipates through Friday afternoon, the pressure gradient will tighten around the subtropical ridge, with moderate to fresh anticyclonic winds expected between the monsoon trough/ITCZ and the ridge through Sunday, with combined seas around the range of 5 to 7 ft. $$ AGUIRRE