Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
473 FXUS66 KSTO 091025 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 325 AM PDT Thu May 9 2024 .SYNOPSIS... Gusty north to east winds continue this morning, diminishing this afternoon. Widespread Valley highs in the 90s Friday into next week. && .DISCUSSION... Troughing will remain over the Great Basin Region through Friday, as high pressure tries to build eastward over California from the Pacific. Main ridging with this high pressure system will spread north of California over the Pacific Northwest. Pressure gradient between these two feature will relax today with diminishing winds. Winds have already diminished over the Sacramento Valley and have expired the wind advisory, as speeds are generally below 20 mph. Will keep the the mountain advisory going where a few gusts from 40-50 mph are still occurring. A gradual warming trend will occur through the week into the weekend with temperatures reaching well above normal levels from 10 to 15 degrees from this afternoon into next week, as Valley highs climb into the upper 80`s and low 90`s. This will represent and huge change from the previous week where temperatures have been mainly in the 60`s and 70`s and will bring brief periods of moderate heat risk during the afternoon hours. Dry weather is expected for most of the area, though the Great Basin low will retrograde (move west) through Friday. This will bring some instability and moisture over the central Sierra. Some Friday afternoon showers and thunderstorms are possible over the Sierra Crest south of Highway 50. && .EXTENDED DISCUSSION (Monday THROUGH Thursday)... Clusters continue to show ridging as the dominant forecast feature through the extended, continuing our stretch of above normal temperatures and generally dry weather. Clusters show some uncertainty regarding the strength of the ridge in the Pacific creating a larger range of possibilities for afternoon temperatures next week. The NBM reflects this high temperature uncertainty, with spread of 8-12 degrees mid to late week across points of the Valley, making exact forecast details uncertain at this point. The spread has lowered slightly, increasing confidence of warm and dr weather continiuing. The current forecast has afternoon high in the upper 80s to mid 90s in the Valley with mainly 70s and 80s for the mountains and foothills. Dry weather continues across the area next week except for a slight chance of Monday afternoon showers and thunderstorms are possible over the Sierra Crest south of Highway 50 but forecast ingrediants don`t look to support development of any impactful thunderstorm or convective activity. && .AVIATION... VFR conditions across interior NorCal over the next 24 hours. In the Valley, northerly surface winds of up to 10-15 kts with local gusts of 15-25 kts through Thu 21z. In foothills and mountain areas, north to east surface wind gusts of 30-45 kts through about 18Z Thursday. Afterwards, wind decrease with 20-35 kts gusts over the mountains and areas of the foothills through 12z Fri and light winds in the Valley. && .STO WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 11 AM PDT this morning for Northeast Foothills/Sacramento Valley-West Slope Northern Sierra Nevada- Western Plumas County/Lassen Park. && $$