000 AXPZ20 KNHC 100917 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0916 UTC Sat Sep 10 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. ...SPECIAL FEATURES... A 1009 mb low pressure center is analyzed at 12.5N113W, and is associated with a tropical wave extending from 17N111W through the low to 10N113W. The low and tropical wave are moving west- northwest at around 15 kt. Scattered to numerous strong convection is within 240 nm in the northwest quadrant of the low. Fresh winds along within combined seas of 6 to 9 ft are observed within the southeast semicircle of the low. The low has a high chance of tropical cyclone development during the next 48 hours. ...TROPICAL WAVES... A tropical wave is over the western Caribbean Sea along 78W, and the extreme southern portion will pass through the Gulf of Panama today and tonight accompanied by a few showers and thunderstorms. A tropical wave extends from the southwest Gulf of Mexico to across southeast Mexico and just west of western Guatemala with the southern portion reaching the east Pacific near 10N93W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N75W to 10N93W to low pressure near 12.5N113W to 10N122W, then resumes from 14N128W to 12N140W. Scattered moderate convection is within 150 nm southwest of a line from 10N99W to 11N102W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A sub-tropical ridge axis extends from northwest to southeast across the western portion of the offshore zones west of the Baja Peninsula. Gentle to moderate northwest flow is expected through the period, except moderate to fresh northwest flow will develop along the central Baja Peninsula through Sunday night. A thermal trough will meander over the Baja Peninsula and across the northern Gulf of California through the period. This will maintain light and variable flow across the Gulf of California through Sunday. Guidance is suggesting moderate south to southwest flow over the gulf along 31N on Sunday night, and fresh to moderate southerly flow in the same area on Monday night. Fresh northerly winds will surge during the overnight hours through the middle of the upcoming week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds forecast to the north of about 07N through the period, while moderate southwest to west flow is expected across the waters generally to the south of 07N. Forecast combined seas of 4 to 7 ft across the entire waters through the period primarily in mixing long-period southwest and swell. REMAINDER OF THE AREA... Except as previously mentioned in the special features section, a weak trough analyzed from weak 1016 mb low pressure near 31N128W to 27N127W will drift west across the waters north of 25N over the weekend, with a surface high east of the trough near 28N123W. Ridging will build from west to east along 26N early next week after the trough dissipates. A trough from 20N127W through weak 1011 mb low pressure near 18N127W to 13N127W will gradually dissipate this weekend while drifting west. Intermittent moderate showers have been observed near the trough. $$ LEWITSKY