000 AXPZ20 KNHC 281617 CCA TWDEP Tropical Weather Discussion...CORRECTION NWS National Hurricane Center Miami FL 1605 UTC Mon Aug 28 2017 CORRECTION TO TROUGH POSITION IN REMAINDER OF AREA SECTION 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 1200 UTC surface analysis and satellite imagery through 1430 UTC. ..TROPICAL WAVES... A tropical wave is along 107W/108W from 24N southward, moving westward 10 knots. Convective precipitation: scattered moderate to isolated strong within 150 nm on either side of 13N110W 17N109W. scattered strong within 45 nm on either side of the wave from 18N to 20N, and within 30 nm on either side of the wave from 22N to 25N. A tropical wave is along 116W/117W from 21N southward, moving westward 10 to 15 knots. Convective precipitation: scattered moderate to isolated strong within 180 nm on either side of the wave from 13N to 14N. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough passes through Costa Rica near 09N84W, to a 1009 mb low pressure center that is near 09N90W, to 08N93W. The monsoon trough continues from 15N96W to 18N108W, 13N120W, 12N130W, and 10N140W. Convective precipitation: scattered strong from 12N to 15N between 100W and 104W. scattered moderate to isolated strong within 400 nm S of axis between 96W and 107W, and within 60 nm N of axis between 96W and 106W. scattered moderate to strong within 180 nm S of axis between 78W and 81W, within 120 nm S between 84W and 87W, and within 180 nm N and 210 nm S of axis between 90W and 93W. Scattered moderate to isolated strong within 60 nm on either side of axis between 129W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge axis extends from NW of the area to 20N121W, which supports moderate to locally fresh NW to N flow across the open Pacific waters W of the Baja California Peninsula. A surface trough extends from NW to SE in the Baja California Peninsula. The trough is forecast to meander over the area, moving at times across the Gulf of California through the early part of the week, with weak surface low pressure developing along the central part of the area. Scattered strong convective precipitation is present near and offshore of Cabo Corrientes with the 107W/108W tropical wave. The main feature of concern during the week will be an area of low pressure which is forecast to develop near 17N106W embedded in the monsoon trough by early Tue. Fresh to locally strong S to SW flow is already present S of the monsoon trough supporting 7 to 9 ft seas. The low is forecast to shift NW passing offshore of Cabo Corrientes Tue evening through early Wed, then between the Revillagigedo Islands and Cabo San Lucas Wed evening through early Thu, and northward thereafter. Fresh to near gale force winds and building seas to greater than 12 ft just offshore will accompany the low, with hazardous winds and seas moving across the entrance to the Gulf of California Wed night, spreading northward thereafter. The official forecast shows a high potential for tropical cyclone development with this low after 48 hours. Light offshore nocturnal flow expected this week, in the Gulf of Tehuantepec, with light to gentle onshore flow during the day. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A 1009 mb low pressure center is embedded in the monsoon trough near 09N90W. Scattered moderate to isolated strong convective precipitation is within 180 nm N and 210 nm S of the low center. This low is forecast to shift NW-W during the next couple of days before dissipating by mid-week. In the Gulf of Papagayo, moderate E flow will prevail this today, then again Fri night into early Sat. Light and variable flow is expected N of the monsoon trough through the week, while moderate to locally fresh southerly winds are expected S of the monsoon trough. Long period southerly cross-equatorial swell, in the form of 7 to 9 ft seas, mainly across the offshore Pacific waters of Colombia and Ecuador will gradually subside through Tue. REMAINDER OF THE AREA... The remnant low of post-tropical cyclone Kenneth finally has degenerated into a trough, that extends from 30N135W to 28N137W to 26N138W. A surface ridge extends from a 1021 mb high pressure center that is near 33N137W, to 28N125W and 20N121W. The trough will dissipate between 24 and 48 hours, while the ridging builds in across the area. This ridging will support mainly moderate to locally fresh trades, and seas of 4 to 7 ft in mixed swell through the week. Moderate to locally fresh southerly monsoonal flow prevails to the south of the monsoon trough W of 120W, while fresh to locally strong flow prevails between 100W and 120W with seas of 7 to 10 ft. These conditions are forecast to persist through Thu night while the low pressure center develops and moves NW across the offshore waters of Mexico. Conditions will improve Fri into the upcoming weekend as the low lifts northward and dissipates. $$ mt