000 AXPZ20 KNHC 280902 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 649 UTC Mon May 28 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 0815 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 13N92W to 10N103W to 09N125W, then transitions to the ITCZ which continues to beyond 09N140W. Scattered moderate and isolated strong convection is present from 06N to 11N between 102W and 126W. Scattered moderate within 60 nm either side of a line from 07N130W to 10N136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... An expansive ridge dominates the region W of 110W. A 1032 mb high centered near 37N137W extends SE across the region to near the Revillagigedo Islands. Fresh to locally strong NW to N winds across the offshore waters of Baja California will become fresh Mon and Tue, then moderate Wed and Thu. Seas of 6 to 8 ft will diminish gradually to between 5 and 6 ft on Tue. Long period NW swell will cause seas N of 27N to build to between 7 and 8 ft Thu and Thu night. Gulf of California: Gentle to moderate NW winds are expected across the Gulf waters through Tue night, with strong afternoon and evening sea breezes recurring along the Mexican coastline from Mazatlan to Guaymas Mon. A low pressure trough developing over the Baja Peninsula will cause winds over the Gulf to become light to gentle by Wed. The same trough of low pressure will bring fresh to locally strong winds to the waters N of 29N Wed night and Thu. Gulf of Tehuantepec: Winds are expected to be light and variable during the next few days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough is gradually shifting back to the S as persistent elongated low pressure over Central America and the Yucatan peninsula weakens. This trend will continue across the regional Pacific waters through at least Thu as the trough continues to slowly sink S and support light to moderate SW to W winds and seas of 4 to 6 ft in SW swell for the waters west of Central America. REMAINDER OF THE AREA... Elsewhere, the ridge building over the north central Pacific is producing a modest pressure gradient across the trade wind belt, with moderate to fresh winds observed in satellite-derived wind data from 09N to 25N to the west of 120W. Seas are running 6 to 9 ft across this zone this morning and will change very little through Tue night. The high is forecast to shift NW Tue through Wed and then migrating W later in the week. This will produce a very slight decrease in areal coverage of the fresh trade winds into mid week. Winds N of the ITCZ between 10N and 15N are forecasted to become locally strong Mon night through Wed. Deepening low pressure over the Desert SW of the U.S. will combine with building high pressure W of California to tighten the pressure gradient along the California coast. Long period N swell generated by these winds will cause seas N of 25N between 120W and 135W to build to between 8 and 10 ft by Wed morning. This area of 8 ft seas will expand to cover all of the waters N of 25N by Thu afternoon, then seas will subside as the swell disperse. $$ CAM