376 AXPZ20 KNHC 150353 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Jul 15 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...TROPICAL WAVES... .A tropical wave is relocated from 07N93W to 13N93W and is estimated to be moving W at 18 kt. Scattered moderate and isolated strong convection is observed S of 08N within 180 nm of the wave axis. .A tropical wave is analyzed from 05N105W through a 1011 mb surface low at 10N105.5W to 16N105W and is moving W at 12 kt. Scattered moderate isolated strong convection is observed S of 14N within 240 nm of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia at 09N76W to the Pacific coast of Costa Rica at 08N83W, then dips Sw through a tropical wave at 07N93W then turns NW and loses identity near the surface low at 10.5N132W. Scatterometer winds indicate an ITCZ develops at 07N118W and extends NW to 10N126W, then resumes near 10N135W and continues Sw to beyond 08N140W. Except as mentioned near the tropical waves, scattered moderate isolated strong convection is observed within 120 nm either side of a line from 05N86W to 09N98W, and from 05N to 18N between 101W and 114W, and from 05N to 17N between 122W and 140W. Scattered moderate isolated strong convection is observed within 30 nm either side of a line from 07N81W to 11N86W, and across the Gulf of California from 27N to 30N. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Pulses of strong northerly drainage flow, accompanied by 6 to 9 ft seas, will continue through Wed night. A surface ridge will meander across the area from near 23N116W to near 15N100W this week. A moderate NW breeze will develop within 90 nm of the Baja Peninsula during the evenings, otherwise gentle anticyclonic northerly winds are expected around the ridge axis, with 3 to 5 ft seas. Gulf of California: Moderate southerly flow will continue along 30N through early Mon morning. Elsewhere, light to gentle southerly flow expected for the next 48 hours. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough which is meandering between 07N and 10N. Moderate southerly winds are forecast S of the monsoon trough for the next several days accompanied by 4 to 6 ft seas. Extended model guidance is suggesting that long period southerly swell, in the form of 7 to 8 ft seas, will arrive along 03.4S to the E of 93W early Thu, and propagate N reaching the far offshore waters along 10N next weekend. REMAINDER OF THE AREA... A weak surface low is analyzed near 10.5N132W with a surface trough extending NE to near 16N130W. The pressure gradient will support fresh to locally strong trades across the tropics roughly within 600 nm N of the low as it reaches near 11N140W late Sun, and then passes 140W by early Mon. Associated conditions should be W of 140W early Tue. This system has the potential to become a tropical cyclone in 3 to 5 days. Refer to the EPAC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for additional information. A surface ridge will meander across the discussion area from 32N140W to 23N116W this week, with moderate to locally fresh anticylonic flow forecast elsewhere around the ridge accompanied by 4 to 7 ft seas. $$ Nelson