720 AXPZ20 KNHC 200905 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Jul 20 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 is analyzed N of 07N along 101W moving W at 15 kt. Scattered moderate to strong convection is noted from 08N to 13N between 98W and 104W. A tropical wave is analyzed from 04N to 15N along 110W moving W at 15 to 20 kt. Scattered moderate convection is noted from 06N to 09N between 109W and 114W. A tropical wave is analyzed from 07N to 16N along 131W moving W at 15 to 20 kt. Scattered moderate convection from 09N to 14N between 129W and 132W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across the entire basin from 10N90W to 10N115W to 13N128W to 11N140W. Scattered moderate isolated strong convection is noted along the entire length of the trough within 45 nm N and 90 nm S of the convergence axis. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge will persist from 31N134W to the Revillagigedo Islands for the next few days, maintaining gentle to moderate breezes across the Mexican offshore waters into early next week. Southerly cross-equatorial swell will propagate into the region by tonight, allowing seas to build to 5 to 7 ft in open waters into early next week. In the Gulf of Tehuantepec, strong N gap wind flow will return late Sat night, producing mixed seas south of the Gulf as wind waves generated near Tehuantepec encounter the longer period southerly swell. Gap winds will be due to lower pressure south of the region along with localized drainage flow. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong nocturnal easterly winds, accompanied by 6 to 8 ft seas, are expected into early next week. Gentle to moderate easterly winds are forecast elsewhere N of the monsoon trough which will meander west of Central America between 07N and 10N. Moderate southerly winds are expected S of the trough axis the next few days accompanied by 4 to 6 ft seas. Long period cross-equatorial southerly swell will continue to propagate N, reaching the far offshore waters between 05N and 14N W of 86W Sun night, and the coast of Central America Mon. Looking ahead, global models are showing increased southwesterly flow into the monsoon trough starting by mid week. This, along with strong gap winds through the Gulf of Papagayo, will help develop multiple low pressure areas along the monsoon trough in offshore waters W of Costa Rica and Nicaragua. Expect widespread shower and embedded thunderstorm activity in this area after Mon. REMAINDER OF THE AREA... A surface trough will move into the waters north of 27N between 125W and 135W Fri, and persist into Sun. The trough will weaken the subtropical ridge, helping maintain moderate to fresh trade winds farther south. Large long period southerly swell is moving across the equator between 90W and 125W, and will continue to propagate northward, affecting an area S of 17N between 80W and 133W by Sun night. Long period northerly swell will propagate into forecast waters N of 27N between 130W and 140W during the upcoming weekend, and then subside on Mon. $$ Mundell