445 FXUS66 KSTO 062020 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 120 PM PDT Sun Jul 6 2025 .DISCUSSION... .SYNOPSIS... Seasonable high temperatures along with dry conditions and breezy onshore winds continue today. Non-zero chance of a high elevation shower/t-storm this afternoon/evening, better chances in the mountains of Shasta County and areas north. Off-shore low will enhance southerly winds tomorrow, with low daytime humidity values in portions of the northern Sacramento Valley will bring elevated fire weather conditions. Slight cooldown in high temperatures Tuesday, then the low pressure moves further inland and weaken by Wednesday, as a ridge begins to build in the Four Corners region. Ridge and departing low pressure will bring periods of breezy north winds to interior NorCal on Thursday, along with a warming trend. Widespread Moderate HeatRisk Thursday- Saturday in the Valley and foothills. && .KEY MESSAGES... * Today - Monday: - Mostly dry weather, non-zero chance of afternoon/evening convection over the mountains of Shasta County. Higher resolution models keep most activity to a minimum and well north of our area. At the time of this writing, little to no cumulus is visible on GOES-18 Satellite, with RAP soundings CAPE. For our area, will most likely see a few cumulus fields developing along higher elevations due to daytime heating/instability. - Winds will be locally breezy at times, strongest through the Delta and over the higher elevations - Warming trend today and tomorrow, as Red Bluff has already reached 95 at 100PM PDT, 4 degrees warmer than the high yesterday. - Elevated fire weather conditions for portions of the northern Sacramento Valley on Monday due to low daytime humidity values and breezy southerly winds, with gusts around 15-25 mph. Highest risk area: along and west of I-5 from around Corning to Redding. * Tuesday - Saturday: - Increased onshore flow with below normal temperatures. Temperatures trend up by the end of the week with above normal highs and widespread Moderate HeatRisk Thursday and Friday - Ensembles have come into better agreement regarding the off- shore low pressure moving inland middle of the week. Low gradually moves eastward, while a high pressure in the desert SW begins to strengthen. Our high temperatures will warm as a result, with slightly warmer than usual (5-8 degrees) by Friday. Widespread Moderate HeatRisk Thursday-Saturday in the Valley and adjacent foothills. .Changes from previous forecast... - No significant changes to the forecast --Wood-- && .AVIATION... VFR conditions across interior NorCal next 24 hours. Periods of breezy onshore winds with gusts up to 15-20 knots in the Delta vicinity, then gusts up to 25-30 kts after 18z Monday. Elsewhere, surface winds generally below 12 kts through 18z Monday. Breezy southerly/southwesterly wind gusts in the Sacramento Valley and northwesterly wind gusts in the northern San Joaquin Valley up to 15-20 kts 18z Monday - 06z Tuesday. Local MVFR conditions possible in HZ/FU vicinity of Shasta County wildfire. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$