Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
037 FXUS66 KSTO 201950 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA Issued by National Weather Service Reno NV 1250 PM PDT Tue May 20 2025 .Discussion... .Synopsis... Warming trend and areas of Moderate HeatRisk in the Valley through the middle of the week as ridging aloft briefly settles in. Temperatures then expected to fluctuate between near and slightly above normal late week into the weekend as a more progressive pattern sets up aloft. Precipitation chances less than 10 percent at this time, but periods of breezy to briefly gusty winds possible. Elevated fire weather conditions expected to persist through the end of the week. && .Key Messages... * Today - Wednesday: -Above normal high temperatures in the 80s to low 90s today,with Valley highs into the mid 90s and areas of Moderate HeatRisk on Wednesday. -Very dry conditions and diurnally breezy winds expected as elevated fire weather conditions persist. * Thursday - Sunday: -Quick moving, dry shortwaves bring periods of breezy to briefly gusty onshore winds Thursday and Friday. -Probability of South-Southwest Wind Gusts > 30 mph: --Thursday: 60-90%, highest across Delta and vicinity --Friday: 30-60%, highest across Delta and vicinity -Despite marginal improvements in RH from onshore flow, elevated fire weather conditions likely continue, especially during periods of strongest winds as systems move through. -Fluctuating temperatures expected, with primarily areas of Minor HeatRisk through the Valley expected. .Changes from previous forecast... -Slight increase in wind magnitude, but also attendant RH recovery with moisture advection Thursday & Friday. && .AVIATION... VFR conditions prevail across interior northern California over the next 24 hours. Northerly wind gusts of up to 15 to 20 knots at times across the Central Valley and Delta through 21Z-00Z Wednesday, then winds become more westerly. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$