234 AXPZ20 KNHC 210404 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 222 UTC Sat Jul 21 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 0600 UTC. ...TROPICAL WAVES... A tropical wave is analyzed from 09N81W to 22N80W. The wave is collocated with a trough in the 700 mb tropical trough diagnostics as well as a maximum in total precipitable water. Scattered moderate and isolated strong convection is noted N of 05N and E of 87W. A tropical wave is analyzed from 06N109W to 17N109W. The wave is collocated with weak troughing in the 700 mb trough as well as a maximum in total precipitable water. Scattered moderate and isolated strong convection is present from 06N to 15N between 105W and 115W. A tropical wave is analyzed from 05N118W to 16N118W. The wave is weak, but can be tracked via the 700 mb tropical trough diagnostics. Scattered moderate and isolated strong convection is seen from 07N to 11N between 115W and 122W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N73W to 08N80W to 10N94W to 09N103W to 10N110W to 09N115W to 12N124W to low pres 1008 MB centered near 13N132W to 14N135W. Scattered moderate and isolated strong convection is noted from 09N to 14N between 98W and 105W. Low pressure measuring 1008 mb is embedded in the monsoon trough near 13N132W. Scattered moderate and isolated strong convection is present from 10N to 14N between 130W and 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends SE from 32N138W to the Revillagigedo Islands. The ridge is maintaining light to moderate NW winds across the Mexican offshore waters. Little change is expected during the next several days. A long-period SW cross-equatorial swell is moving into the region today. The extensive swell event will cause seas to build to between 8 and 9 ft in open waters of all the forecast zones through early next week. In the Gulf of Tehuantepec, pulses of strong northerly gap winds will occur during late night and morning hours through Mon morning before fading on Tue. Wind waves from these northerly winds will interact with the SW swell event to produce mixed seas south of the Gulf up to 9 ft by Mon before fading on Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong easterly winds during late night and morning hours are expected into early next week. Seas from these easterly winds will interact with the SW swell event to produce mixed seas southwest of the Gulf up to 10 ft by Mon before fading on Tue. Easterly winds of only fresh breeze or weaker are forecast elsewhere N of the monsoon trough which will meander west of Central America between 07N and 10N. Southerly winds of only fresh breeze or weaker are expected S of the trough axis the next few days. A long-period southwesterly cross-equatorial swell is moving into the region today, allowing seas to build to 9 ft in open waters through early next week. An altimeter pass at 1800 UTC along 90W showed peak seas of 8 to 9 ft near the equator. REMAINDER OF THE AREA... A surface ridge is in place from 32N138W to the Revillagigedo Islands is maintaining moderate trade winds N of the monsoon trough, S of 18N and W of 115W. Little change in this pattern is expected for the next several days. See discussion above regarding the tropical wave near 108W. Large long period SW swell is moving across the equator between 90W and 130W, and will continue to propagate N, affecting most of the area east of 130W before fading on Tue. Satellite-derived sea height data showed seas as high as 9 ft crossing the equator near 100W. $$ CAM