Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
427 FXUS66 KSTO 152044 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 144 PM PDT Sat Jun 15 2024 .SYNOPSIS... Critical fire weather conditions likely tonight 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 than normal temperatures late next week. && .DISCUSSION... Key Points - A Red Flag Warning is in effect from 11 PM tonight - 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. Short-Term Discussion (Today THROUGH Tuesday)... Patchy high clouds cover much of the northern Sacramento Valley this afternoon on GOES West Satellite imagery, though much of the rest of the sky over interior NorCal remains clear. Tonight sees the start of critical fire weather conditions in much of the Sacramento Valley and nearby terrain, and subsequently a Red Flag Warning goes into effect for areas below 2000 ft. Highest risk is expected to occur along the western edge of the northern and central portions of the Sacramento Valley, with wind gusts reaching up to 25 to 35 mph and daytime humidities in the low teens. Overnight recoveries will also be poor, with humidities expected to only reach the 30s to mid 40s. These conditions will last into Monday evening; it is imperative to practice fire safety during this time! Temperatures will be near to slightly below seasonable through Monday, with highs in the Valley reaching the mid to high 80s, and higher elevations seeing temperatures around the 60s and 70s. Tuesday sees more normal temperatures with highs in the low 90s in the Valley, and 80s and 70s in the foothills and mountains respectively. Otherwise, relatively calm weather returns Tuesday and into mid-week. && .EXTENDED DISCUSSION (Wednesday THROUGH Saturday)... As we move further into the week, upper level ridging causes the warming trend to continue on Wednesday and into next weekend, with the likely return of triple digits by Friday or Saturday. Widespread Moderate HeatRisk is expected Friday and Saturday as well, along with areas of Major HeatRisk in the central Sacramento Valley and nearby foothills on Saturday. Probabilities of reaching at least 100 degrees are 50- 80% throughout the Valley on Friday, and 60 to 85% on Saturday. && .AVIATION... VFR conditions over interior NorCal next 24 hours. Surface wind mainly at or below 12 kts until around 07z Sunday in the northern Sacramento Valley, when northerly gusts up to 25 kts possible. Also, in vicinity of the Delta westerly/southwesterly surface winds could get up to 20 kts overnight. Stronger and gustier winds expected Sunday and Monday. && .STO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 11 PM this evening to 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. && $$