238 AXPZ20 KNHC 251549 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Jul 25 2018 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 1545 UTC. ...TROPICAL WAVES AND TROPICAL LOWS... A tropical wave is analyzed N of 06N between 80W and 81W and is estimated to be progressing W at 18 kt. Scattered moderate and isolated strong convection is noted within 45 nm either side of the wave axis including over Panama. A tropical wave is analyzed from 05N to 15N along 98W and is estimated to be progressing W at 15 kt. Scattered moderate and isolated strong convection is noted from 08N to 10N within 180 nm either side of the wave axis. A tropical wave is analyzed from 04N115W to 17N113W and is estimated to be progressing W at 15 kt. Scattered moderate isolated strong convection is noted N of 08N within 360 nm E and within 240 nm W of the wave axis. A surface low is forecast to develop along this wave near 12N121W on Thu and near 14N126W on Fri. This low has a medium chance of becoming a tropical cyclone in 3 to 5 days. A 1010 mb surface low is analyzed at 11N128W and is moving W at 15 kt accompanied by scattered moderate isolated strong convection within 180 nm over the N semicircle of the low. This low is forecast to reach near 10.5N133W on Thu and near 10.5N138.5W on Fri accompanied by fresh winds and 7 to 9 ft seas within 240 nm on the N quadrant. A tropical wave is analyzed from 05N141W to 16N138W within isolated moderate and strong from 07N to 15N between 133W and 140W. This wave and associated convection will pass W of the discussion area over the next 24 hours. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Pacific coast of Colombia at 07N78W and passes through tropical waves at 08N80W and 10N98.5W to 11N104W, then turns SW through a tropical wave at 09N115W TO 09N120W where scatterometer winds indicate a transition to an ITCZ which turns NW to near the 1010 mb low pressure at 11N128W and continues W to 12N140W. Except as mentioned near the tropical waves and the tropical low, isolated moderate and strong convection is observed within 180 nm of the monsoon trough and ITCZ. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad trough will meander N-NW to S-SE across the Baja Peninsula across the entrance to the Gulf of California to near 20N107W the remainder of this week with a second weak trough forecast to move E through the offshore waters W of the northern Baja Peninsula late this week. A NW to SE surface ridge will meander just beyond 250 NM seaward of the Baja Peninsula the remainder of the week. Light breezes are forecast W of Baja Peninsula the remainder of the week accompanied by 4 to 6 ft seas. Gulf of Tehuantepec: Moderate onshore flow is expected during the daylight hours becoming light offshore flow during the overnight hours. Gulf of California: Gentle to moderate southerly flow expected through the end of the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh easterly flow is expected through Fri afternoon. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough which is meandering between 07N and 10N. Moderate to fresh southerly winds are forecast S of the monsoon trough for the next several days accompanied by 5 to 7 ft seas. REMAINDER OF THE AREA... A surface ridge will meander across the discussion area from 30N140W to near 20N114W with a weak trough analyzed N of the ridge from 35N130W to 31N137W. See the tropical waves section above for details on a series of waves and lows analyzed s of the ridge. Long period northerly swell, in the form of 7-9 ft seas, is forecast N of 30N between 119W and 123W through the upcoming weekend. $$ Nelson