000 AXPZ20 KNHC 080915 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0915 UTC Sun Jul 8 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVES... A tropical wave has an axis along 101W N of 05N, moving westward at 10 to 15 kt. Scattered moderate and isolated strong convection are from 04N to 13N between 99W and 106W. A tropical wave has an axis along 108W from 07N to 19N, moving westward at 10 to 15 kt. Isolated thunderstorms are within 90 nm of the wave axis S of 09N. A tropical wave has an axis along 121W from 04N to 17N, moving westward at 10 to 15 kt. Numerous moderate and isolated strong convection are from 07N to 13N between 116W and 126W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N83W to 07N98W. The ITCZ begins near 07N109W and extends to 08N119W, then resumes near 10N122W to 09N130W to beyond 08N140W. Aside from convection associated with the tropical waves, scattered moderate and isolated strong convection are from 06N to 12N between 126W and 140W, and from 03N to 07N E of 83W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak ridge axis extends from high pressure NW of the region to near the Revillagigedo Islands. A surface trough extends across Baja California, while another surface trough is just west of Baja California extending from 30N118W to 25N120W. Due to the presence of these troughs, and the lack of strength of the surface ridge, a weak pressure pattern is in place N of 15N W of 97W across the offshore waters promoting mainly gentle winds. The trough W of Baja California is expected to remain nearly stationary the next few days, which will help maintain the weak flow over the region. Meanwhile, NW swell generated by strong winds offshore California will continue to propagate offshore Baja California Norte through today, generating seas of 6 to 8 ft. Gulf of Tehuantepec: High pressure north of the region along with nocturnal enhancements will support strong northerly winds with seas up to 9 ft at night through tonight. The high will strengthen Mon through Wed night which will help increase the nocturnal winds to near gale force, with fresh to strong winds lingering into the daytime hours. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong nocturnal winds will continue downstream of the Gulf of Papagayo the next several nights, with seas to 8 ft. Gentle to moderate easterly winds are forecast elsewhere north of the monsoon trough, which will meander between 06N and 09N. Gentle to moderate southerly winds are expected south of the trough axis. Long period cross-equatorial swell greater than 8 ft currently across the offshore waters of Ecuador and Colombia will linger across these locations through Mon before diminishing below 8 ft by Mon night. REMAINDER OF THE AREA... The post-tropical remnant low of Fabio is centered near 25N137W, moving WNW. Scattered showers continue N of the center to beyond 30N between 133W and 139W. Although an 1802 UTC scatterometer pass indicated that winds of 20 to 30 kt were within about 210 nm of the northern semicircle of the low, the pressure of the low continues to rise. Therefore winds produced by the pressure gradient between this low and high pres NW of the region are likely peaking near 25 kt this morning with seas to 11 ft. A larger area of swell 8 ft or greater covers the waters W of a line from 30N132W to 19N133W. The winds will continue to decrease in areal coverage and intensity through today as the low continues to weaken and degenerates into a trough of low pressure by tonight. The associated area of swell will also continue to shrink in size, with seas diminishing below 8 ft over this region by Mon morning. Strong NW winds north of the area along the California coast will cause 8 to 9 ft seas in northerly swell to reach the waters N of 28N between 120W and 126W from now through most of Mon, before retreating to along and N of 30N through midweek. Cross equatorial swell combined with wind waves from the Gulf of Papagayo will generate seas to 9 ft S of 12N and E of about 103W today and Mon. $$ Latto