000 AXPZ20 KNHC 221521 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1520 UTC Mon Jun 22 2020 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 1500 UTC. ...SPECIAL FEATURES... A tropical wave with axis along 110W south of 17N is moving westward around 15 kt. This wave is embedded within a broad area of low pressure centered several hundred miles south of the southern tip of Baja California, near 12N110W. Numerous moderate scattered strong convection is noted in recent satellite imagery from 10N to 14N between 110W and 114W. Environmental conditions are forecast to be conducive for gradual development, and a tropical depression could form during the next two to three days while the disturbance moves westward, away from the coast of Mexico. This system has a medium chance of tropical cyclone formation during the next 48 hours. A broad area of low pressure located more than 1000 miles SW of the southern tip of the Baja California peninsula continues to produce disorganized showers and thunderstorms. Recent satellite imagery shows numerous moderate isolated strong convection from 09N to 12N between 126W and 130W. Environmental conditions are expected to be conducive for gradual development, and this system could become a tropical depression during the next few days while it moves generally westward. This system has a medium chance of tropical cyclone formation during the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... The southern portion of a Caribbean Sea tropical wave is along 82W and north of 04N, moving westward at 15-20 kt. Scattered moderate convection is noted from 04N to 06N within 120 nm west of the wave axis. A tropical wave with an axis along 93W north of 03N is moving westward at 10-15 kt. Total precipitable water satellite imagery depicts a very moist environment behind the wave axis. Scattered moderate isolated strong convection is occurring from 07N to 14N within 180 nm of the wave axis. A weak tropical wave with an axis along 116W is moving westward at 5-10 kt. Scattered moderate isolated strong convection is noted from 07N to 12N between 114W and 120W. A tropical wave with an axis along 139W is moving westward at 10 kt. Isolated moderate convection is noted from 08N to 12N within 90 nm of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N75W to 07N81W to 12N107W to 09N118W to 11N131W to 10N140W. Besides the tropical wave convection described above, scattered strong convection is occurring within 150 nm of the monsoon trough between 100W and 108W. Scattered moderate convection is noted from 04N to 07N east of 79W, and within 150 nm south of the monsoon trough between 122W and 126W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a surface high pressure ridge offshore of Baja California and a low pressure trough over the Gulf of California is supporting moderate to locally fresh NW winds over the Baja offshore waters. Seas are generally 4-6 ft in mixed NW and SW swell. Little change in marine conditions is expected through midweek, but the ridge is expected to weaken by late week as offshore wind speeds diminish. Elsewhere, moderate southerly winds will prevail this week in the Gulf of California, possibly becoming fresh by Fri in the northern Gulf. An area of disturbed weather is forecast to form south of the coast of Mexico in a couple of days. Development is expected to occur after that time, and the system could become a tropical depression by late this week as the disturbance moves west- northwestward parallel to the coast of Mexico. Please monitor the latest NHC Tropical Weather Outlook for the latest updates. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh easterly winds are ongoing across the Papagayo region this morning, with seas ranging from 5-7 ft. Moderate to fresh winds will continue pulsing in the Papagayo region through this week. Elsewhere, gentle to moderate S to SW winds prevail south of the monsoon trough. Cross-equatorial SW swell is maintaining 5-7 ft seas in this area. Little change is expected over the next few days. REMAINDER OF THE AREA... Please see the Special Features section above for more details on the potential for tropical cyclone development later this week. A broad high pressure ridge dominates the waters north of 15N this morning. The pressure gradient between this ridge and the monsoon trough is supporting moderate to fresh winds roughly from 12N to 20N west of 120W, based on overnight scatterometer data. Seas are generally 6-8 ft in this area, with locally higher seas in convection associated with the tropical waves and disturbances described above. Elsewhere, moderate to locally fresh southerly flow is noted south of the monsoon trough between 105W and 120W. Seas peak around 8 ft in this region with locally generated wind waves combined with background SW swell. In fact, S to SW swell dominates much of the waters south of 15N and east of 120W. This swell will gradually decay over the next couple days. Another set of cross-equatorial southerly swell may build seas over the southern waters late this week. $$ B Reinhart