Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
126 FXUS66 KSTO 012027 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 127 PM PDT Tue Jul 1 2025 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .DISCUSSION... .SYNOPSIS... 20-30% chance for mountain thunderstorms through mid-week. Lightning on dry fuels may lead to easier fire starts. Otherwise warm and dry weather continues with periodically breezy onshore winds. Widespread Moderate HeatRisk persists through Wednesday. Quiet and cooler for the end to the week into the weekend. && .KEY MESSAGES... * Through Mid Week: - Above normal temperatures persist through Wednesday with widespread Moderate HeatRisk, although increased onshore flow brings some relief to the Delta vicinity - Slight (10-30%) probability of thunderstorms Tuesday during the afternoon and early evening hours across the mountains of interior NorCal. Highest thunderstorm probabilities over the northern mountains and Coastal Range. - Low (20%) chance for showers and thunderstorms over the northern Sacramento Valley late Tuesday evening - Thunderstorm chances shift Wednesday to near the Sierra crest and west - Lightning on dry fuels may lead to easier fire starts. A Red Flag Warning has been issued for the northern Coast Range, Shasta County mountains and Burney Basin until 8 PM Tuesday. * Late Next Week: - Quiet weather late week into the weekended - Onshore winds will cool temperatures to seasonal norms to slightly below average - Coolest day will be Friday - Slight warming over the weekend into next week .Changes from previous forecast... - Added low, up to 20% chance for showers and thunderstorms over the northern Sacramento Valley late this evening && .AVIATION... VFR conditions expected to prevail across interior NorCal next 24 hours, although some potential for brief MVFR/IFR in isolated SH/TS at RDD and RBL through 06z. Surface winds 12 kts or less, except in the Delta vicinity where southwest gusts 20 to 25 kts are expected through 14Z Tuesday. Otherwise mountain thunderstorms possible across Coast Range and southern Cascades through 10z Tuesday. && .STO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 8 PM PDT this evening for Burney Basin and Northeast Plateau in Shasta County Including Northwest Lassen NF north of Lassen NP-Eastern Mendocino NF-Eastern Portion of Shasta/Trinity NF-Northern Sierra Foothills from 1000 to 3000 Ft. Includes portions of Shasta-Trinity and Butte Units- Northern Sierra Including Lassen NP and Plumas and Lassen NF/S West of the Sierra Crest (West of Evans Peak-Grizzly Peak- Beckworth Peak)-Southeast Edge Shasta-Trinity NF and Western Portions of Tehama-Glenn Unit. && $$