Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
149 FXUS66 KSTO 130828 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 128 AM PDT Tue Aug 13 2024 .SYNOPSIS... Near to slightly below normal temperatures persist this week alongside periodically breezy late day winds. && .Discussion... As of early this morning, GOES-West satellite imagery shows mostly clear skies across interior NorCal. This should allow for another night of appreciable radiative cooling and low temperatures in the 50s to low 60s for most, with a few readings in the 40s at higher elevations. The trough that brought isolated showers and breezy winds on Monday will continue to progress northeastward out of the region today. Temperatures look to rise a few degrees today and Wednesday as a period of transient ridging aloft builds in, but are still expected to remain near to slightly below normal. High temperatures in the upper 80s to mid 90s are anticipated across the Valley and foothills, with generally 70s to 80s at higher elevations. A shortwave trough then looks to travel along the California- Oregon border late Wednesday into Thursday, before becoming largely stationary through the end of the week. This will be the result of large scale ridging beginning to build in across the Four Corners and Intermountain West working to block the troughing from any eastward advancement. For interior NorCal, this means a return to primarily below normal temperatures through the end of the week as onshore flow persists. High temperatures in the 80s to low 90s are expected for Valley and foothills locations as 70s to 80s prevail at higher elevations. An isolated shower cannot be completely ruled out across the northern and central Sacramento Valley with the introduction of the shortwave, but current probabilities of precipitation remain around 10% or less at this time. Humidity recovery will likely see a slight downward trend through midweek before moderating once again as onshore flow becomes reinforced by the building trough. && .EXTENDED DISCUSSION (Saturday THROUGH Tuesday)... Latest cluster analysis continues to converge on the solution of a deepening trough off the coast of the Pacific Northwest through the weekend. There are then some indications of the trough weakening, but still remaining stationary, into early next week. This pattern would lead into a continuation of below normal temperatures through the weekend, with a slight upward trend to near normal temperatures through early next week. Resultant probabilities of high temperatures less than 90F are around 50% to 70% for the Valley and adjacent foothills through the weekend, falling to 25% to 45% on Monday and Tuesday. Additionally, as the trough deepens, somewhat breezier conditions can be expected over the weekend. && .AVIATION... VFR conditions prevail across interior NorCal next 24 hours except isolated MVFR in HZ/FU in vicinity of fires. Surface winds generally less than 12 kts, although late day gusts to 20 kts possible in Delta vicinity. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$