Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
619 FXUS66 KSTO 112026 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 126 PM PDT Sat May 11 2024 .SYNOPSIS... Seasonably warm weather will result in areas of moderate heat risk through this weekend and into the week ahead. Mostly dry and occasionally breezy conditions look to accompany this warm stretch as well. && .DISCUSSION(Through Tuesday)... As of early this afternoon, quiet weather is being observed across interior NorCal. Temperatures are warming back into the 80s in the Valley and 60s to 70s at higher elevations at this time, with generally light winds as well. With upper level ridging remaining the predominant feature for NorCal through the weekend, afternoon high temperatures will continue to climb into the 90s in the Valley and 70s to low 80s at higher elevations. A shortwave trough does look to travel across SoCal moving into Monday. This will result in a slight 3 to 5 degree cool down for Monday afternoon high temperatures, as well as a slight (15 to 30%) chance for a late day, isolated shower or thunderstorm along the northern Sierra. Otherwise, temperatures begin to warm again by Tuesday, with the Delta Breeze being the only other appreciable weather feature bringing occasional gusts to 25 mph throughout the Delta and the vicinity in the evening. Scattered areas of moderate heat risk are expected throughout the Valley this weekend into early next week. && .EXTENDED DISCUSSION (Wednesday THROUGH Saturday)... Despite being in the vicinity of the aforementioned SoCal trough, broad upper level ridging will continue to dominate NorCal through midweek. As a result, the warmest temperatures of the year so far are expected to occur on Wednesday afternoon, with mid to upper 90s throughout the Valley and upper 70s to 80s at higher elevations. Additionally, there is a 30% to 70% chance of reaching triple digits in the Sacramento Valley (highest probabilities >50% in the central Valley between Sacramento and Red Bluff) by Wednesday afternoon. This will lead to fairly widespread areas of moderate heat risk in the Valley, north of the Sacramento metro, on Wednesday. There is then some synoptic uncertainty from late week into the weekend as a Gulf of Alaska trough looks to eject across the Canadian prairies and into the northern Plains. While overall impacts look to be minimal for NorCal, with the resultant flattening ridge aloft, there is an increasing trend toward a period of breezier south- southwesterly winds and temperatures cooling to near normal from Thursday into next weekend. As a result, heat risk diminishes to generally below moderate levels from Thursday into next weekend. && .AVIATION... VFR conditions persist across interior NorCal through the forecast period. Generally light surface winds less than 12 kts expected, except occasional gusts to 20 kts in the Delta and vicinity after 00z Sunday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$