000 AXPZ20 KNHC 120753 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Jun 12 2019 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 0745 UTC. ...TROPICAL WAVES... A tropical wave is near 97W/98W moving west at around 10 kt. Nearby convection is described below. A tropical wave is near 120W/121W moving west at around 10 kt. Nearby convection is described below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from Panama near 09N78W to 11N88W to 10N106W. The ITCZ continues from 10N106W to 07N120W to 08N130W to 12N137W. Scattered moderate and isolated strong convection was noted from 05N to 08N between 87W and 93W, from 08N to 11N between 91W and 95W, and from 12N to 15N between 90W and 93W. Scattered moderate convection was noted from 08N to 10N between 102W and 107W, from 06N to 08N between 125W, and from 11N to 14N west of 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a surface ridge over eastern Mexico and low pressure associated with the monsoon trough is forcing strong to near gale force gap winds over the Gulf of Tehuantepec. Combined seas peak near 10 ft in NE wind waves and S swell, while 8 ft seas likely extend well downstream of the Gulf. The Tehuantepec gap winds will diminish by early this afternoon, then will strengthen again Thu into early Fri as high pressure builds into the northern Gulf of Mexico and tightens the pressure gradient. A persistent high pressure ridge west of Baja California will maintain gentle to moderate NW winds over the offshore waters through the upcoming weekend. Winds may pulse to fresh speeds during the evening hours near the coast, especially south of Punta Eugenia. Winds over the Gulf of California will generally remain light to gentle due to a weak pressure gradient for the next several days, with the exception of fresh nocturnal SW gap winds in the northern Gulf Thu night. A new set of long period SW swell will reach the southern Mexican offshore waters this weekend, but seas are expected to remain less than 8 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Nocturnal offshore flow will pulse to fresh speeds in the Gulf of Papagayo for the next several days. The strongest winds will occur during the late night and early morning hours with the nocturnal drainage flow. Otherwise, fairly tranquil conditions will persist off Central America through the next several days under a weak pressure pattern. Gentle to moderate SW winds will prevail south of the monsoon trough. A new set of long period SW swell will reach the southern waters on Sat with seas likely building to 8 ft between Ecuador and the Galapagos Islands Sat night through Sun night. REMAINDER OF THE AREA... A broad high pressure ridge persists across the northern waters with an axis extending southeastward from near 30N140W to beyond the Revillagigedo Islands. Recent scatterometer data showed generally moderate trade winds south of the ridge and west of 130W, with locally fresh winds associated with a surface trough located along 138W/139W. This feature will continue supporting fresh winds and combined seas to 8 ft into early Thu as it tracks westward beyond 140W. Otherwise, little change in winds or seas is expected through Sun night. A new set of long period SW swell will reach the far SW waters by Thu night, then propagate NE across the region through the upcoming weekend. Seas are expected to build to 8 ft or greater just south of the Equator by Fri and persist through the weekend. $$ Lewitsky