Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
405 FXUS66 KSTO 160810 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 110 AM PDT Sun Jun 16 2024 .SYNOPSIS... Critical fire weather conditions through Monday night across the Sacramento Valley due to gusty northerly winds and low relative humidity. Below average temperatures and dry conditions continue over the next several days before we see a return to warmer weather late in the week. && Key Points - A Red Flag Warning is in effect until 8 PM Monday across the majority of the Sacramento Valley due to low daytime relative humidity, gusty northerly winds, and poor overnight recoveries. - Northerly winds continue early next week maintaining some locally elevated fire weather conditions Tuesday. - Normal or near normal temperatures continue through most of the week, with a gradual warming trend late week into the weekend, and widespread Moderate HeatRisk expected on Friday. .Discussion... Clear skies cover the region. Surface pressure gradient continues to trend offshore with some northerly gusts of 15-20 mph currently being reported over the northern Sacramento Valley and surrounding terrain. Humidity remains very low - currently in the 20s over much of the valley and foothill and mountain ridges while in the mid 40s to around 60 in the Delta and southern Sacramento Valley where a light onshore gradient lingers. Winds will increase this morning as mixing develops with gusts of 20-30 mph expected in the valley. A little stronger and more widespread northerly breeze is forecast for Monday (behind a stronger short-wave trough brushing by to the north) with gusts up to 35 mph possible in portions of the valley before winds decrease Monday night and Tuesday. Humidity will also be very low (in the single digits and teens (lowest Monday) with poor overnight recovery) and combined with the northerly breezes will result in periods of critical fire weather conditions. With the trough overhead, temperatures will remain a little below average early this week before beginning to warm a bit by the middle of the week as it weakens. && .EXTENDED DISCUSSION (Thursday THROUGH Sunday)... Warming trend expected beyond midweek as upper troughing weakens and progresses and heights trend up. Widespread triple digit heat returns this weekend in the Central Valley with mainly 80s to 90s for the mountains and foothills. && .AVIATION... VFR conditions over interior NorCal next 24 hrs. In Central Vly, widespread NWly sfc wind up to 20 kts turning SWly vcnty of Delta. In foothills/mtns, areas NW-NE sfc wind gusts up to 30 kts. && .STO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 8 PM PDT Monday for Central Sacramento Valley in Glenn, Colusa, Yuba, Northern Sutter, and Butte County Below 1000 Ft-Eastern Mendocino NF-Northern Sacramento Valley to Southern Tehama County Line Below 1000 Ft-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-Southern Sacramento Valley in Yolo-Sacramento Far Western Placer, southern Sutter and Solano County Below 1000 Ft. && $$