By Reginald Stanley. Posted June 23, 2021, 6:48 PM.

A influx of subtropical moisture into the region, unusual for late June, has increased since Tuesday into the region. This has resulted in widespread pop-up showers and even thunderstorms everywhere from the deserts and mountains, to the coasts and valleys Wednesday.

Nine active WeatherCurents stations have recorded measurable precipitation as of Wednesday evening, although amounts have generally been small. The greatest total so far is 0.16 inches recorded in Moreno Valley, while other locations have received less than 0.10 inch. WeatherCurrents stations in Temecula, De Luz, Fallbrook, Hemet, San Jacinto, Lake Elsinore, French Valley and Riverside (Orangecrest) have all observed measurable rainfall Wednesday, in addition to Moreno Valley. In East Highland, a total of 0.23 inches was reported as of 8 PM Wednesday evening (courtesy of Peter Michas), as well as 0.09 inches in nearby Yucaipa (courtesy of Don Kramer). In Temecula Valley's Wine Country, 0.01 inch fell (courtesy of Jim Sappington) while 0.02 inches was reported in Central Murrieta (although no measurable rain was recorded at the nearby WeatherCurrents station in northwest Murrieta). Much of the southern portion of the Inland Empire also witnessed a sudden intrusion of smoke into the area, originating from a wildfire burning near Pala in northern San Diego County Wednesday afternoon.

A weak trough of low pressure off the coast of California is expected to push the subtropical moisture off to the east starting late Wednesday night, returning to an onshore flow pattern for a couple of days until strong high pressure develops over the Pacific Northwest during the weekend. Hotter temperatures are forecast to return with the high pressure ridge early next week, along with the possibility of monsoonal moisture further out in the forecast.