000 AXPZ20 KNHC 031531 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1530 UTC Thu Aug 3 2017 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 1200 UTC surface analysis and satellite imagery through 1515 UTC. ..TROPICAL WAVES... A tropical wave is analyzed to the N of 06N along 90W/91W and is progressing W at an estimated 15 kt. This wave will continue W across southern Guatemala and Mexico reaching the Gulf of Tehuantepec area late tonight through Friday. Scattered moderate convection is from 08N to 12N between 89W and 91W. A tropical wave is analyzed to the N of 11N along 103W/104W with several cyclonic swirls noted along the wave axis. Numerous moderate and isolated strong convection is from 12N to 18N between 101W and 106W. Recent microwave data does not show any closed surface circulation despite the recent expansion and deepening of convection. Even so, fresh to strong E to SE winds and seas of 8 to 9 ft are funneling up along the coast across the offshore waters. These winds and seas will diminish and subside as the tropical wave weakens while moving away from the area through the end of the week. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 07N78W to 06N90W to 07N95W, then resumes from 15N98W to low pressure near 12N112W to 09N137W. The intertropical convergence zone axis extends from 09N137W to 08N140W. Scattered moderate and isolated strong convection is from 07N to 12N between 105W and 110W, from 09N to 12N between 114W and 117W, from 06N to 10N between 130W and 135W. Scattered moderate convection is from 05N to 07N between 136W and 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the tropical waves section for information on a vigorous tropical wave SW of the coast of Mexico. Otherwise, a low level trough will meander across the Baja California Peninsula while a NW to SE oriented ridge extends across the area from 1017 mb high pressure near 26N126W to 20N115W. A gentle to locally moderate NW breeze is expected through the weekend and into early next week W of the Baja California Peninsula, with combined seas of 4 to 6 ft primarily in mixed long period NW and cross-equatorial southerly swell. Gentle southerly flow will persist across the Gulf of California except moderate southerly flow expected to the N of 30N on Friday night and again on Saturday night. In the Gulf of Tehuantepec, fresh northerly drainage winds are expected late tonight into early Friday, with guidance hinting at a very brief and localized strong surge on late Friday night into early Saturday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, moderate to locally fresh offshore winds this morning will reoccur late tonight through sunrise Friday. Otherwise, moderate southerly winds are expected S of the monsoon trough axis through the upcoming weekend and into early next week with mainly 3 to 6 ft seas, except building to 4 to 7 ft in southerly swell between the Galapagos Islands and mainland Ecuador. REMAINDER OF THE AREA... The remnant low of Irwin is located near 29N132W and is expected to soon weaken to an open trough. A ridge will rebuild from N of the Hawaiian waters to across the area N of the monsoon trough Friday through early next week. Mainly gentle to moderate trades and seas of 4 to 6 ft in mixed swell will prevail through the forecast period, except in the W central portion where weak low pressure will develop near 08.5N134W through the afternoon. Winds will increase to fresh to strong on the E side of the low supporting building seas of 7 to 9 ft, before shifting W of the area by early Saturday. $$ Lewitsky