![]() |
The Latest NWS Regional Area Forecast Discussions
Select Your Area NWS Weather Forecast Office
NWS Area Weather Forecast Discussion
County Warning Area [CWA]: STO Regional NWS Weather Office: Sacramento, CA 888 FXUS66 KSTO 232053 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 153 PM PDT Sun Mar 23 2025 .SYNOPSIS... Warm and dry weather is expected this weekend and into early this week. Cooler and periods of active weather return by mid to late this week with breezy southerly winds. && .DISCUSSION... Ridging builds across interior NorCal today through early this week, resulting in drier and warmer conditions across the area. Daytime temperatures will be 10 to 20 degrees above normal (Today- Tuesday) with widespread Minor HeatRisk across the Valley on Monday and Tuesday. Valley temperatures are forecast to be in the mid to upper 70s this afternoon, with highs in the low to mid 80s early this week. Warmest temperatures are still expected on Tuesday, with the National Blend of Models indicating a 75-100% probability of high temperatures greater than 80 degrees across the Valley and portions of the Delta and foothills. Blended guidance suggests a slight cooling trend by Wednesday, with the latest NBM projecting highs in the low 70s to around 80 for the Valley, Delta, and foothills. Northerly winds will be breezy at times today, with gusts 15 to 20 mph along the I-5 corridor in the Sacramento Valley. Winds will gradually diminish in the afternoon hours. Ensembles depict southwest flow developing on Wednesday ahead of an approaching trough. This system is expected to bring chances for light, low-impact precipitation mainly over the mountains later Wednesday through early Friday morning. In addition, the NBM shows a 15-30% probability of thunderstorm development Wednesday afternoon and evening, mainly across portions of the northern Sacramento Valley, with less than a 10% chance elsewhere in the Valley. Gusty southerly winds are also expected with this system on Wednesday, particularly across portions of the northern/central Sacramento Valley and mountains. The NBM projects a 20-50% probability of wind gusts greater than 35 mph across the northern and central Sacramento Valley on Wednesday. && .EXTENDED DISCUSSION (Thursday THROUGH Sunday)... A shortwave trough moves across the region Thursday into Friday, with light precipitation mainly over the mountains. Amounts continue to trend lighter with this system. WPC guidance suggests 0.10-0.33" of precipitation over the Sierra north of US Hwy 50, and up to 0.66" over the mountains of Shasta County. Much of the Sacramento Valley is expected to be see less than 0.10" (except for the northern Sacramento Valley with up to 0.10"-0.20"). This will be a fairly warm system as well, with snow levels starting above 8000 feet on Wednesday before lowering to around 5000-6000 feet by Thursday. This will allow for a light dusting of snow with up to an inch along higher terrain. Gusty southerly winds are also expected with this system on Thursday. The NBM shows a slightly increased probability of thunderstorm (now 15-20%) on Thursday afternoon/evening across portions of the northern Sacramento Valley and adjacent foothills and mountains. Other than some light showers over the mountains north of I-80 on Friday, a brief lull in precipitation is expected through Saturday afternoon. Ensembles and clusters indicate unsettled and potentially wetter weather arriving Sunday and continuing through Monday, with possible mountain travel issues, but strength and timing remain uncertain at this point. && .AVIATION... VFR conditions expected to continue over the next 24 hours. Locally breezy north to east wind gusts up to 15-20 kts are expected across portions of the Sacramento Valley and over the Sierra through 00z Monday. Elsewhere, surface winds less than 12 kts are expected. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
|