000 AXPZ20 KNHC 130912 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Jun 13 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 0900 UTC. ...TROPICAL WAVES... A tropical wave is near 88W extending from Central America southward to near 06N, moving west at around 15 kt. Only scattered showers and isolated thunderstorms are noted with this wave. A tropical wave is near 103W moving west at around 10 kt. Scattered moderate and isolated strong convection is noted from 06N to 11N between 100W and 108W. A tropical wave is near 128W moving west at around 10 kt. Only isolated to scattered showers are noted with this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from Costa Rica near 10N86W to 10N100W to 08N121W. The ITCZ extends from 08N121W to 06N127W, then resumes from 06N129W to 05N140W. Scattered moderate and isolated strong convection is noted from 04N to 07N east of 82W, from 06N to 11N between 90W and 97W, from 11N to 13N between 94W and 99W, and from 05N to 11N between 107W and 118W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A high pressure ridge west of Baja California is supporting gentle to moderate NW winds off the coast of Baja California, except fresh to strong right near Cabo San Lucas per recent scatterometer data. This ridge will persist through the weekend and into early next week with gentle to moderate NW flow prevailing offshore. Winds may pulse to fresh speeds during the evening hours near the coast, especially between Punta Eugenia and Cabo San Lazaro. Gap winds have briefly diminished over the Gulf of Tehuantepec, however, strong northerly winds are expected this evening into Fri as high pressure builds into the northern Gulf of Mexico and tightens the pressure gradient. Fresh SW to W gap winds will develop over the northern Gulf of California tonight into early Fri. Elsewhere, gentle to moderate SE to S flow will prevail over the central and southern Gulf of California into early next week. 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 to strong speeds in the Gulf of Papagayo through the weekend and into early next week. The strongest winds will occur during the late night and early morning hours with the nocturnal drainage flow. Seas will build to 8 ft on Fri and Fri night as strong NE flow prevails across the Gulf. Elsewhere, gentle to moderate SW flow with scattered showers and thunderstorms will prevail south of the monsoon trough for the next several days. Otherwise, fairly tranquil conditions will persist off Central America under a weak pressure pattern. A new set of long period SW swell will reach the southern waters late Fri night with seas building to 8 ft between Ecuador and the Galapagos Islands over the weekend. REMAINDER OF THE AREA... A high pressure ridge extends across the northern waters from near 30N140W southeastward to near the Revillagigedo Islands. A surface trough just west of 140W is tightening the pressure gradient south of the ridge, and earlier scatterometer data showed fresh winds associated with this feature from 13N to 16N west of 138W. The surface trough will continue moving westward over the next couple days, but persistent moderate to locally fresh trades will maintain 8 ft seas over the waters near 140W through Fri evening. Elsewhere, gentle to moderate winds prevail across much of the high seas domain. A 04Z altimeter pass showed 3-5 ft seas north of 20N and west of Baja California, with 4-7 ft seas south of 20N within the gentle to moderate trade winds. Little change in the overall pattern is expected through Mon, and winds are expected to remain 20 kt or less across the high seas. A new set of long period SW swell will reach the far SW waters tonight, then propagate NE across the region through the weekend. Seas will build to 8 ft or greater south of the Equator by Fri and persist through the weekend. A reinforcing set of SW swell could reach the far SW waters by Mon night, resulting in 8-9 ft seas south of the Equator and west of 110W. $$ Lewitsky