000 AXPZ20 KNHC 010937 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Sep 1 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 12N89W to 11N105W to 1010 MB low pressure near 10.5N118W to 10N123W to 13N135W to beyond 12N140W. Scattered moderate isolated strong convection is from 10N to 12.5N between 91W and 96W. Scattered moderate convection can be found from 05N to 07N between 87W and 90W, from 07N to 11N between 86W and 88W, within about 90 nm of a line from 09N97W to 11N102W, from 08N to 10N between 108W and 115W, and within about 120 nm S of trough between 130W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the region producing gentle to moderate NW winds and seas of 4-6 ft across the Pacific waters along the Baja California peninsula. These marine conditions are forecast to persist through the weekend. A thermal trough will meander over the Baja Peninsula, and across the northern Gulf of California supporting light southerly flow across the Gulf of California or Sea of Cortez into the upcoming weekend when moderate to fresh southwest flow is briefly expected N of 30N. A low pressure system, possible a tropical cyclone, is forecast to develop S of the Gulf of Tehuantepec region and could affect the forecast zone PMZ027 during the weekend with increasing winds and building seas. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to locally fresh southwesterly winds will prevail south of the monsoon trough axis with light to gentle west to northwest winds forecast north of it. Long period cross equatorial SW swell will continue to dominate the area with seas ranging between 4 and 7 ft. Winds and seas could increase across forecast zone PMZ111 on Friday as a low pressure, possible a tropical cyclone, develops close to this region. REMAINDER OF THE AREA... A surface ridge covers most of the waters N of 20N, extending from 1029 mb high pressure located NW of the forecast area. Hurricane Lester is now west of the discussion area but fresh to strong winds in the 20-30 kt range and seas of 10-15 ft continue to affect the forecast waters from 17N to 25N W of 135W. These marine condition will continue to shift westward over the next 12-24 hours. Scatterometer data show moderate to fresh SW winds S of the monsoon trough between 90W and 95W, and between 100W and 107W. Marine guidance continues to suggest an increase in the monsoonal flow with seas building to 8 ft roughly across the waters from 08N to 10N between 100W and 120W. An area of disturbed weather is located about 500 miles southeast of Acapulco, Mexico. Environmental conditions are expected to become conducive for development of this system, and a tropical depression is likely to form over the weekend while the low moves west-northwestward or northwestward near the coast of Mexico. Currently, the chance of tropical cyclone formation is assessed to be medium in the short term and high through 5 days. $$ GR