Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
015 FXUS66 KSTO 050933 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 233 AM PDT Sun May 5 2024 .SYNOPSIS... Lingering showers and snow showers today, mainly in the mountains as the weather system exits the region. Drier, warmer conditions return this week with gusty north to east winds mid-week. && .DISCUSSION... Current radar shows showers and snow showers continuing over portions of interior NorCal, mainly in the foothills and mountains. Temperatures are currently trending approximately 10 to 25 degrees cooler than this time yesterday morning, valid at 230 AM PDT. The Winter Storm Warning remains in effect above 4000 feet to address lingering snow showers and mountain travel impacts through 0800 this morning. Additional minor accumulations of up to 1-2 inches will be possible through the day today. Highs will be slightly warmer than yesterday, however still well below normal for early May climatology. Valley highs are forecast to be in the low to mid 60s, with 40s to 50s in the foothills and 30s to low 50s in the mountains. Drier and warmer weather returns to interior northern California this week as the influence of high pressure returns to the region. A day to day warming trend will bring Valley temperatures back to the 80s by the middle of the week, with continued rise through late week. As high pressure builds over the eastern Pacific and troughing continues over the Great Basin, increasing north to east winds are favored. Current guidance suggests the breezy northerly winds begin to increase on Tuesday and become stronger into Wednesday. The Extreme Forecast Index (EFI) highlights the typical north to east wind-prone areas such as the western Sacramento Valley and mountains for these stronger winds on Wednesday. The National Blend of Models (NBM) suggests a 55 to 85 percent probability of wind gusts of 40 mph or greater in those aforementioned areas. && .EXTENDED DISCUSSION (Thursday THROUGH Sunday)... Breezy north to east winds are expected to linger into Thursday as high pressure continues over the eastern Pacific and troughing over the Great Basin. Ensemble guidance and cluster analysis then favor upper level ridging as the dominant synoptic influence over the extended forecast period, bringing continued dry conditions and warmer than normal temperatures. The National Blend of Models (NBM) suggests a 25 to 65 percent probability of Valley highs reaching 90 degrees from Friday through Sunday. && .AVIATION... Northern Sierra, widespread IFR/LIFR with scattered snow showers continue thru about 18Z with areas of MVFR vicinity lingering showers thru 00Z Monday. Otherwise, VFR conditions predominate. Local southwest to west surface wind gusts 15-20 kts after 21Z, otherwise wind generally less than 12 kts. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 8 AM PDT this morning for West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. && $$