639 AXPZ20 KNHC 252000 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 1800 UTC surface analysis and satellite imagery through 2000 UTC. ...TROPICAL WAVES AND TROPICAL LOWS... A tropical wave is analyzed N of 06N between 81W and 82W and is estimated to be progressing W at 18 kt. Scattered moderate and isolated strong convection is noted within 150 nm either side of the wave axis including over Panama. A tropical wave is analyzed from 05N to 15N along 100W and is estimated to be progressing W at 15 kt. Scattered moderate and isolated strong convection is noted from 08N to 10N within 90 nm either side of the wave axis. A tropical wave is analyzed from 05N117W to 17N115W and is estimated to be progressing W at 15 kt. Scattered moderate isolated strong convection is noted N of 08N within 150 nm E and within 240 nm W of the wave axis. A surface low is forecast to develop along this wave near 12N123W on Thu and near 13.5N127W on Fri. This low has a medium chance of becoming a tropical cyclone in 3 to 5 days. A 1011 mb surface low is analyzed at 11N129W and is moving W at 15 kt accompanied by scattered moderate isolated strong convection within 120 nm over the N semicircle of the low. This low is forecast to reach near 10.5N134W on Thu and near 10.5N139W on Fri accompanied by fresh winds and 7 to 9 ft seas within 240 nm on the N quadrant. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Pacific coast of Colombia at 07N78W and passes through tropical waves at 08N81W and 10N100W to 11N104W to the tropical wave at 11N117W TO 09N120W where scatterometer winds indicate a transition to an ITCZ which turns NW to near the 1011 mb low pressure at 11N129W and continues W to 11N140W. Except as mentioned near the tropical waves and the tropical low, scattered moderate isolated strong convection is observed within 150 nm of lines from 07N80W to 06N92W, and from 10N103W to 10N113W, and from 08N125W to 09N140W. ...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 for 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 then 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