000 AXPZ20 KNHC 211605 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Jun 21 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...TROPICAL WAVES... A tropical wave that recently moved across Central America is analyzed with its axis along 86W north of 05N to inland Nicaragua, moving westward at 10-15 kt. Scattered moderate to strong convection is ahead of the wave within 30 nm of line from 08N86W to 08N89W. Scattered moderate convection is within 60 nm east of the wave from 06N to 09N. Model simulated precipitation guidance indicates that convection will increase with this wave over the next 24-48 hours as it tracks across the far eastern Pacific waters. A tropical wave with axis along 97W from 04N to 56N is moving westward at 10-15 kt. Scattered moderate to isolated strong convection is within 180 nm west of the wave from 09N to 11N. This wave moving through a very moist and unstable environment. The shower and thunderstorm activity associated with it is likely to increase over the next 24-48 hours. A tropical wave with axis along 111W from 04N to 14N is moving westward near 15 kt. Scattered moderate convection is within 60 nm of 08N111W. Isolated showers and thunderstorms are elsewhere from 06N to 09N between 110W and 112W. A tropical wave with axis extending from 16N129W to 04N133W is moving westward at 15-20 kt. Middle level cyclonic rotation can be seen in satellite imagery centered near 14N126W, with a weak inverted trough reflected below this at the surface. Scattered moderate to isolated strong convection is noted along this wave and to the west of the wave to 133W from 09N to 12N. This activity should remain rather active through tonight as it will continue to be aided by an upper-level trough that is roughly along 137W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1010 mb low over northwestern Colombia near 09N74W to across southern Costa Rica to 11N93W to just east of the tropical wave along 111W. It resumes at 08N112W to 09N124W to just east of the tropical wave that extends from 16N129W to 04N133W. It resumes at 08N133W to beyond the area at 09N140W. Outside of convection described above with the tropical waves: Scattered moderate to strong convection is within 180 nm south of the trough between 99W and 104W and within 60 nm south of the trough between 85W and 89W. Scattered moderate to isolated strong convection is within 180 nm north of the trough between 96W and 100W. Scattered moderate convection is within 90 nm north of the trough between 110W and 112W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Overnight scatterometer data indicated that gentle to moderate northwest wind continue across the offshore waters of Baja California, while gentle to moderate northwest to west winds were observed from Cabo Corrientes to Puerto Angel. Seas were running 4-6 ft in mainly northerly swell. Low pressure over the southwestern U.S. will continue to deepened through this morning, with an associated surface trough extend over the Gulf of California. Southwest to west gap winds have begun to increase over the northern Gulf of California tonight, and continue to increase through this afternoon and evening, reaching to near gale force intensity late tonight, with seas building to 5- 8 ft. These winds will diminish to strong speeds early Sat and to gentle to moderate speeds early Sat. Scattered to numerous showers and thunderstorms along with gusty winds are possible over the extreme southern part of Mexican offshore waters on Sat as a tropical wave passes just south of the Tehuantepec area. Low pressure may form beginning early next week a few hundred miles southwest of the Tehuantepec region and along the outer offshore waters there. This is expected to produce fresh to locally strong easterly winds and building seas to the southeast Mexican offshore waters, and bring additional shower and thunderstorm activity to these waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Overnight scatterometer data showed fresh offshore gap winds occurring from the Papagayo region to El Salvador ahead of the approaching tropical wave over Central America. Elsewhere north of 11N, gentle easterly flow prevailed. Active weather associated with this approaching tropical wave, and a strong early season tropical wave across the west central Caribbean are expected through the weekend. Southerly swell from the southern hemisphere will continue propagating northeastward across the regional offshore waters, keeping seas in the 5-6 ft range before seas build to 5-8 ft Sun. REMAINDER OF THE AREA... A 1032 mb high remains quasi-stationary well north of the area near 42N139W, with a ridge extending southwestward to just SW of the Revillagigedo islands. To the south of the high pressure, northeast to east trades of 10-15 kt continue. Little change in the position of the high or the speed of trades is expected through the weekend. A tighter gradient is allowing for northeast to east winds of 15-20 kt north of about 27N and west of 130W, along with waveheights in the range of 8-10 ft in northerly swell. The swell is being generated by persistent gale force winds off the coast of California. The focus of this swell will move east and gradually shrink in size this weekend. Farther south, long-period cross-equatorial swell is resulting in waveheights of 8 ft south of about 08N. This swell will be replaced by yet another set of primarily southwest swell that will arrive on Sat bumping waveheights up about a foot. This swell will subside some late Sun into early Mon. $$ Aguirre