000 AXPZ20 KNHC 110231 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Sep 11 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...SPECIAL FEATURES... Tropical depression 16-E has formed at 13.9N 114.9W, or about 700 sm ssw of the southern tip of the Baja California Peninsula. The estimated minimum central pressure is 1008 mb. The maximum sustained winds are 30 kt, with gusts to 40 kt. The depression is moving nw, or 310 deg 1t 10 kt. Scattered moderate isolated strong convection is currently observed due e, and over the entire nw semicircle within 150 nm either side of a line from 12N110W to 16N112W to 13N118W. Fresh southerly winds, and combined seas of 7 to 10 ft in s swell, are observed elsewhere out to 360 nm over the se semicircle of the low. Model guidance continues to indicate favorable environmental conditions for continued strengthening to a tropical storm in 12 hours and to hurricane force in 48 hours. Refer to the latest NHC forecast advisory at WMO/AWIPS headers WTPZ21 KMIA/MIATCMEP1 for additional details. ...TROPICAL WAVES... A tropical wave extends n from 12N96W across the western Gulf of Tehuantepec, and has been moving w at 10 to 15 kt. Associated convection is noted along the wave near 12N, and along the n shore of the Gulf of Tehuantepec. Another tropical wave is over the w Caribbean along 82W, and will pass through Costa Rica and Nicaragua tonight into Sun accompanied by a few showers and tstms. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends off the Pacific coast of Costa Rica at 10N85W to 11N100W, then dips nw to 14N105W where is loses identity. Scatterometer winds indicate that the monsoon trough forms again sw of the newly formed depression at 11N116W, and turns nw through 13N135W to beyond 12N140w. Scattered moderate isolated strong convection is observed along, and to the s of the eastern segment of the monsoon trough within 180 nm either side of a line from 06N80W to 13N104W. Isolated moderate to strong convection is observed along and to the s of the western segment of the monsoon trough within 90 nm either side of a line from 09N117W to 13N135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A sub-tropical ridge axis extends from nw to se across the western portion of the offshore zones w of the Baja Peninsula. Gentle to moderate nw flow is expected through the period, except moderate to fresh nw flow will develop along the central Baja Peninsula briefly on Mon evening. A thermal trough will meander over the Baja Peninsula and across the northern Gulf of California through the period. This will maintain light, mostly southerly flow across the Gulf of California through Sun. Guidance is suggesting moderate s to sw flow over the northern gulf waters along 31N on Sun night, and fresh to moderate southerly flow in the same area on Mon night. The low level flow will clock to the nw across the entire Gulf of California on Wed. Model guidance indicates a fresh northerly surge will develop across, and just downstream of the Gulf of Tehuantepec on Sun and Tue nights with seas building briefly to 6 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds are forecast to the n of about 08N through the period, while moderate sw to w low level flow is expected across the discussion waters generally to the s of 08N. Forecast combined seas of 4 to 7 ft across the entire area through the period primarily in mixing long-period sw and swell. REMAINDER OF THE AREA... Except as previously mentioned in the special features section concerning TD 16-E, a weak trough analyzed from 27N132W to 32N127W will continue to drift w across the waters n of 25N and gradually fill through Mon. A 1020 mb surface high pressure e of the trough near 27N127W will lose identity as the sub-tropical ridge rebuild from w to e along 26N early next week after the trough dissipates. $$ Nelson