245 AXPZ20 KNHC 202135 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Aug 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 1800 UTC surface analysis and satellite imagery through 2000 UTC. ...TROPICAL WAVES... A tropical wave along 93W is moving W 15-20 kt. Satellite imagery suggests two short amplitude waves are moving through this region between 83W and 102W and reorganizing. Widely scattered moderate to strong convection is from 06N to the Mexican coast along 16N between 86W and 100W. A tropical wave along 112W-113W is moving W around 15 kt. Widely scattered moderate to strong convection is found from 07N to 17N between 110W and 120W. A tropical wave along 128W-129W is moving W around 15 kt. Widely scattered moderate to strong convection is found from 07N to 18N between 120W and 132W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pres 1010 mb near 09N74W and meanders WNW to near 13N123W to 10N140W, where it terminates. Scattered moderate to strong convection is seen from 07N to 11N between 100W and 106W, from 13N to 16N between 133W and 139W, and from 07N to 10N between 132W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge across the NE Pacific is centered on a 1032 mb high near 46N138W and extends S and SE, entering the forecast waters near 30N131W, then extends SE to just beyond the Revillagigedo Islands. This ridge will support a weak to modest pressure gradient across the offshore waters of Baja California, to produce gentle to moderate NW winds through Wed before the ridge strengthens modestly and the pressure gradient tightens across Baja California Norte Thu and Fri. Seas will generally remain in the 4-5 ft range through Wed. Surface troughing over the Baja Peninsula will maintain a generally light wind regime over the Gulf of California through Fri night, and allow for afternoon sea breezes and nocturnal land breezes to dominate. Strong N to NE gap winds will affect the Gulf of Tehuantepec Tue night through Thu night, and are forecast to peak near 30 kt late Wed night. Seas of 4 to 6 ft during the daytime could build to near 8 ft each of these nights, and 8-10 ft late Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will linger near 09N 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 to locally strong each night. Seas are expected to remain 6-7 ft downstream of Papagayo during this time. REMAINDER OF THE AREA... Elsewhere, the pressure gradient between ridging across the northern waters and the ITCZ will support gentle to moderate trades and 4-7 ft seas in mixed swell N of the ITCZ and W of 120W through the middle of this week. Sea heights will be relatively low for most of the forecast area this week. Mixed SE and SW swell has produced seas S of 01S and W of 105W to briefly build to 8 ft this morning and will continue through Tue morning before subsiding to less than 8 ft. A much more robust round of long period swell could arrive from the Southern Hemisphere toward the end of this week and cause seas near the Equator to begin building on Sat. $$ Stripling