611 FXUS66 KSTO 242059 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 159 PM PDT Tue Jun 24 2025 .DISCUSSION... .SYNOPSIS... Isolated mountain shower and thunderstorm chances from Highway 50 southward this afternoon. Seasonable temperatures accompanied by dry weather and periodically breezy onshore winds through the remainder of the week. A warming trend with areas of Moderate HeatRisk is then anticipated heading into the weekend. Isolated mountain thunderstorms could return this weekend into early next week. && .KEY MESSAGES... * This Week: -Slight 5-10% chance of isolated mountain thunderstorms this afternoon from Highway 50 southward. -Seasonable temperatures expected, with Delta, Valley, and foothills high temperatures in the 80s to 90s and 70s to 80s at higher elevations. * The Weekend: -Warming trend into the weekend with high temperatures across the Delta, Valley, and foothills in the 90s to lower triple digits and 80s to low 90s expected at higher elevations. --Some areas of Moderate HeatRisk on Friday, becoming more widespread by Saturday. --Probability of Valley high temperatures > 100F this weekend: Northern/Portions of the Central Sacramento Valley: 50-95%; Delta, S. Sac Valley, N. San Joaquin Valley: 10-35% -Dry weather continues with lessening onshore flow. -Slight (10-20%) chance of isolated mountain thunderstorms this weekend through early next week during the afternoon and early evening hours. Highest chances Sunday into early next week. .Changes from previous forecast... -Potential for isolated mountain showers and thunderstorms this weekend through early next week. && .AVIATION... VFR are generally expected over the next 24 hours across interior Northern California. Winds will be mainly from the south gusts 15 to 20 kts in the Sacramento Valley and from the northwest in the northern San Joaquin Valley through 06Z Wednesday. Through the Delta, westerly gusts 20 to 25 kts are expected until around 14Z Wednesday. Additionally, there is a 15 to 20% chance for isolated mountain showers and thunderstorms mainly south of I-80 today until around 01Z Wednesday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$