Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
092 FXUS66 KSTO 140807 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 107 AM PDT Tue May 14 2024 .SYNOPSIS... Unseasonably warm weather will result in areas of moderate heat risk through Thursday. A few isolated, late day showers or thunderstorms will be possible over the Sierra this afternoon and evening. Otherwise, mostly dry and locally breezy conditions look to accompany this warm stretch. && .DISCUSSION (Today through Friday)... Warmer temperatures today. Weak northerly flow over the parts of the central valley today will help to start a brief warming trend through Wednesday with Wednesday expected to be the warmest day this week. The hottest temperatures could be near 100 degrees for parts of the central and northern Sacramento valley with a 20 to 65 percent probability of reaching 100 degrees on Wednesday. The greatest probability of reaching a 100 degrees is in the western central Sacramento valley. Flow through the Delta will help to keep temperatures cooler further south in the low to mid 90s. Some cooling is expected on Thursday with a little better cooling for areas with a Delta influence as the Delta breeze is expected to increase starting late Wednesday/Wednesday night. Moderate heat risk is expected today and Wednesday for most of the central valley with the exception of areas with a Delta influence that will have a minor heat risk. Continued Moderate heat risk for a smaller portion of the central valley Thursday, with the highest risk in the central Sacramento valley. The high pressure ridge will begin to breakdown on Thursday with the north valley winds ending and shifting southerly in the Sacramento valley during the day. This along with a continued moderate Delta breeze will help to lead to cooling over the interior for Friday. One more day of afternoon and early evening thunderstorms with a chance mainly around highway 88 and south today. Thunderstorms should be starting near the crest for the western slopes then the storms look to be moving south-southwest to west direction mostly this evening. Slight movement of any storms is expected this afternoon. Local heavy rainfall and mostly small hail is expected with thunderstorms today. && .EXTENDED DISCUSSION (Saturday THROUGH Tuesday)... Cooling trend through the extended forecast period as upper troughing increases over interior NorCal. High temperatures cool from around 6 to 12 degrees above normal Saturday, to seasonal normal Tuesday. Increasing instability with lowering heights will lead to a slight chance of isolated afternoon showers or thunderstorms over the Northern Sierra Nevada Monday and Tuesday. && .AVIATION... VFR conditions over interior NorCal next 24 hrs exc isolated MVFR/IFR possible in -shra/-tsra over SierNev, south of Highway 50 btwn 20z-04z. Sfc wind mainly below 12 kts except vcnty of Delta, SWly sfc wind up to 20 kts possible. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$