719 AXPZ20 KNHC 231541 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1541 UTC Thu Aug 23 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave is just E of the area over western Colombia along 76W moving W at 10 to 15 kt. Associated convection is described in the Monsoon Trough section below. A tropical wave extends N of 03N along 89W northward to El Salvador moving W at 10 to 15 kt. Associated convection is described in the Monsoon Trough section below. A tropical wave from 04N to 19N along 119W is moving W around 15 kt. Associated convection is described in the Monsoon Trough section below. A tropical wave from 04N131W to low pressure near 12N131W to 18N130W moving W at 10 to 15 kt. Associated convection is fairly limited. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pressure near 09.5N76W to 08N90W to 08N104W to 12N120W to low pressure near 12N131W. The intertropical convergence zone axis extends from 10N133W to 07N140W. Scattered moderate and isolated strong convection is within 300 nm S of the axis E of 82W, within 180 nm N of the axis between 83W and 90W, from 05N to 09N between 92W and 101W, from 06N to 13N between 109W and 122W, and also within 120 nm S of the axis between 132W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... In the Gulf of Tehuantepec, fresh to near gale force northerly winds and seas of 8 to 11 ft persist this morning due to a tight pressure gradient between high pressure N of the area and lowering pressure farther S in the tropics. These gap winds and related seas will linger through tonight, then will return again Sat night and Sun night. Elsewhere, ridging across the waters north of 20N will support moderate to occasionally fresh winds funneling along the coast of Baja California through the next several days, with 3 to 5 ft seas, with the highest seas off Baja California Norte. Winds will increase to fresh to strong offshore of Baja California Norte Mon night with seas building to 6 to 8 ft. Meanwhile, gentle to moderate southerly flow will persist over the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will linger between 08N to 12N during the next few days. Winds on both sides of the trough axis will generally be light to moderate. The main exception to this will be over the Gulf of Papagayo, where nocturnal offshore winds will pulse to fresh the next several nights, except fresh to strong Fri night into early Sat. Seas are expected to remain less than 8 ft downstream of Papagayo with the winds. REMAINDER OF THE AREA... Elsewhere, the pressure gradient between ridging across the northern waters and the monsoon trough will support gentle to moderate trades and 4 to 7 ft seas in mixed swell north of the monsoon trough and west of 120W through the weekend. Seas are reaching 8 ft in a small area from 17N to 19N W of 138W, mainly due to a mix of NE and SE swell. This will persist through much of today then subside. Elsewhere, sea heights will be relatively low for most of the forecast area this week. Robust long period swell could arrive from the Southern Hemisphere toward the end of this week and cause seas near the Equator to begin building over the weekend. $$ Lewitsky