000 AXPZ20 KNHC 172109 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1948 UTC Thu Aug 17 2017 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 2100 UTC. ...SPECIAL FEATURE... A surface low is analyzed near 13.5N112.5W, with estimated mean sea level pressure of 1008 mb. Strong winds, with seas in the 7 to 9 ft range are noted within 120 NM east semicircle of the low. Scattered moderate isolated strong convection is currently observed within 180 nm southwest semicircle of the low. Environmental conditions are favorable for tropical cyclone formation as this low moves northwestward the next couple of days. Refer to High Seas Forecast under WMO/AWIPS headers FZPN03 KNHC/MIAHSFEP2 for additional information. ..TROPICAL WAVES AND TROPICAL LOWS... The axis of a tropical wave is near 92W north of 06N, moving west at about 20 kt. Isolated strong convection was noted from 06N to 11N between 91W and 96W. The axis of a tropical wave is near 107W from 07N to 21N, moving west at 15 kt. Scattered moderate isolated strong convection is noted from 16N to 20N between 105W and 111W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 07.5N95W to 13N106W through low pres near 13.5N112.5W to 12N120W to 13N128W to 12N140W. Scattered moderate isolated strong convection was noted within 60 NM north of the monsoon trough east of 90W. Scattered moderate isolated strong convection was noted within 60 NM south of the monsoon trough between 115W and 119W. Scattered moderate isolated strong convection was noted 90 NM north of the monsoon trough between 122W and 127W. Scattered moderate isolated strong convection was noted within 90 NM south of the monsoon trough between 136W and 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge will dominate the forecast waters west of Baja California producing mainly gentle to moderate northerly winds and seas in the 4-6 ft range the remainder of the week into the upcoming weekend. A surface trough will meander across the Baja California Peninsula and Gulf of California through Sat night, with a surface low developing intermittently over the northern Gulf of California. Gulf of California...gentle southerly flow will persist across the Gulf of California through the upcoming weekend. Gulf of Tehuantepec: winds will pulse to fresh to strong during the overnight and early morning hours through Monday, with seas are building to 6-8 ft with these winds. On Monday, winds are forecast to reach near gale force, with seas building to 9-10 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: fresh to strong offshore winds are expected during the overnight and early morning hours through Friday morning, with moderate to fresh winds thereafter. Otherwise, gentle NE to E winds are expected N of the monsoon trough, while moderate southerly winds are expected S of the monsoon trough axis through the upcoming weekend with 3 to 6 ft seas throughout. REMAINDER OF THE AREA... High pressure of 1028 mb extends a ridge southeast to near 23N116W. Except as previously mentioned in the special features section, moderate to locally fresh anticyclonic flow is forecast N of the monsoon trough and W of 120W. Long period southerly swell, with seas in the 6 to 8 ft range, is observed S of 06N between 110W and 120W. These seas will subside to less than 8 ft tonight. $$ AL