428 AXPZ20 KNHC 222033 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2033 UTC Wed Aug 22 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 1800 UTC surface analysis and satellite imagery through 2030 UTC. ...TROPICAL WAVES... A tropical wave extends N of 06N along 80W northward into the western Caribbean Sea moving W at around 15 kt. Associated convection is described in the Monsoon Trough section below. A tropical wave N of 04N along 97W extending to southern Mexico is moving W around 15 kt. Convection is limited with this tropical wave. A tropical wave from 03N to 19N along 111W is moving W around 15 kt. Associated convection is described in the Monsoon Trough section below. A tropical wave from 04N126W to 1012 mb low pressure near 13N126W to 17N126W is moving W around 10 to 15 kt. Associated convection is described in the Monsoon Trough section below. A tropical wave that was previously analyzed along 140W has moved W of the area into the Central Pacific basin. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N79W to 08N100W to low pressure near 13N126W to 10N137W. Scattered moderate and isolated strong convection is within 300 nm S of the axis E of 88W, within 210 nm SW of the axis between 111W and 119W, within 150 nm SE of the axis between 122W and 127W, and also within 210 nm NW of the axis between 125W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... In the Gulf of Tehuantepec, fresh to strong northerly winds will pulse through Thu night due to a tight pressure gradient between high pressure north of the area and lowering pressure farther south in the tropics. Seas may build briefly to between 8 and 10 ft during these pulses. 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. 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 moderate to fresh offshore winds will pulse at night. 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 ITCZ will support gentle to moderate trades and 4 to 7 ft seas in mixed swell north of the ITCZ and west of 120W through the weekend. 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