000 AXPZ20 KNHC 232045 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2045 UTC Tue Jun 23 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 1800 UTC surface analysis and satellite imagery through 2030 UTC. ...SPECIAL FEATURES... An elongated area of low pressure, roughly centered near 12.5N118.5W, is producing a large area of disorganized cloudiness and thunderstorms. Scattered moderate and isolated strong convection is noted within 180 nm N semicircle and 300 nm SW quadrant of the low. Environmental conditions are forecast to be conducive for some gradual development over the next couple of days, but the disturbance is forecast to move over cooler waters after that time, which should inhibit further development. This system has a medium chance of tropical cyclone formation during the next 48 hours. A nearly stationary area of low pressure is centered near 10N130.5W. Although the associated shower and thunderstorm activity has decreased since yesterday, environmental conditions are forecast to be conducive for gradual development, and this system is likely to become a tropical depression during the next few days while it moves slowly westward. This system has a medium chance of tropical cyclone formation during the next 48 hours, and a high chance during the next five days. Disorganized showers and thunderstorms located a few hundred miles S-SW of the Gulf of Tehuantepec are associated with a tropical wave with an axis near 98W. Scattered moderate and isolated strong convection is noted from 12N to 16N between 92W and 98W. Environmental conditions appear favorable for development, and the system is likely to become a tropical depression in a few days while it moves W-NW parallel to the coast of Mexico. This system has a medium chance of tropical cyclone formation during the next 48 hours, and a high chance during the next five days. 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 north of 02N, moving westward at 20-25 kt. Numerous moderate and scattered strong convection is noted from 05N to 09N within 240 nm E and 120 nm W of the wave axis. An area of disturbed weather is forecast to form south of the Gulf of Tehuantepec by late this week. Environmental conditions are expected to be conducive for gradual development of this system over the weekend as it moves W-NW parallel to the coast of Mexico. This system has a low chance of tropical cyclone formation during the next five days. A tropical wave axis is along 92W north of 06N, moving westward at 20 kt. Scattered moderate convection is noted from 06N to 11N within 240 nm E of the wave axis. A tropical wave axis is along 98W north of 05N, moving westward at 10-15 kt. This wave remains well-defined in precipitable water imagery and local wave diagnostic tools. See the Special Features section above for more information on this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N77W to 07N84W to 14N112W to 1009 mb low pressure near 12.5N118.5W to 09N122W to 1007 mb low pressure near 10N130.5W to 09N140W. Besides the convection previously described, scattered moderate and isolated strong convection is noted within 180 nm of the monsoon trough between 99W and 105W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A high pressure ridge persists well offshore of Baja California this afternoon, and a low pressure trough remains draped along the Baja peninsula near the Gulf of California. Recent scatterometer data shows mainly gentle with locally moderate winds over the Baja offshore waters. Gentle to moderate SE winds are noted along the Gulf of California. Elsewhere, showers and thunderstorms associated with the recent passage of a tropical wave are likely producing gusty winds and locally rough seas south of the Tehuantepec region. In general, seas remain 4-6 ft offshore and 3 ft or less in the Gulf of California. Offshore high pressure will weaken later this week, allowing winds offshore of Baja California to diminish Thu through the weekend. Winds and seas will increase off the coast of southern Mexico late this week and into the weekend as a couple of low pressure systems with the potential for tropical cyclone formation move parallel to the coast of Mexico. Please see the NHC Tropical Weather Outlook for the latest updates. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Earlier scatterometer data showed moderate to locally fresh winds over and downstream of the Papagayo region, where seas are 5-7 ft. Numerous showers and thunderstorms are noted in GOES-16 satellite imagery and lightning data offshore of Panama, in association with the passage of a tropical wave near 82W. These storms are likely producing gusty winds and rough seas near the entrance to the Gulf of Panama. Elsewhere, gentle to locally moderate SW monsoon flow persists south of the monsoon trough. Seas remain 4-7 ft across the waters as decaying cross-equatorial SW swell lingers in the region. Fresh winds will pulse in and downstream of the Papagayo region through this weekend, possibly strengthening Thu into Fri as low pressure forms off the coast of southern Mexico. Elsewhere, moderate monsoon flow will prevail across the southern offshore waters for the next several 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 and over the upcoming weekend. Moderate to occasionally fresh trades continue between a ridge across the northern waters and the active monsoon trough. Recent scatterometer passes reveal an area of fresh to strong winds between 115W and 125W, associated with broad low pressure along the monsoon trough. Wave heights likely reach 8-10 ft within this enhanced monsoon flow. Seas are generally 6-8 ft within the trades west of 130W. Elsewhere, SW swell continues to decay over the southern waters, as seas have subsided to 4-6 ft over much of the region. Another set of cross-equatorial southerly swell may build seas over the southern waters late this week. Additionally, monsoon flow will likely strengthen as two low pressure systems with the potential for tropical cyclone development form off the coast of southern Mexico. This may result in hazardous winds and seas off southern Mexico later this week and into the upcoming weekend. $$ B Reinhart