402
FXUS66 KSTO 172012
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
112 PM PDT Tue Jun 17 2025

For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.

.DISCUSSION...

.SYNOPSIS...
Warming trend today, followed by areas of Moderate HeatRisk in
the Valley and foothills on Wednesday. Cooling trend expected late
this week with stronger onshore flow Thursday-Friday. Elevated
fire weather conditions forecasted for midweek into the weekend
for low humidity and gusty winds.

&&

.KEY MESSAGES...

* Today-Wednesday:

 - Warming temperatures with areas of Moderate HeatRisk in the
   Valley and foothills by Wednesday as ridging develops, hottest
   over the northern Sacramento Valley.

 -Probability of Valley High Temperatures on Wednesday > 100F:
  --Northern Sacramento Valley/Foothills & Eastern Portions of the
   Greater Sacramento Area: 40-80%

  --Southern/Central Sacramento Valley & N. San Joaquin
   Valley: 20-45%

 -Combination of hot weather with dry conditions may bring a
  brief period of locally elevated fire weather conditions, mainly
  across the northern Sacramento Valley.

*Thursday-This Weekend:

 -Gradual cooling trend expected with stronger onshore flow
  Thursday-Friday. Strongest winds expected through the Delta and
  over the Sierra. South to west forecasted shifting to north to
  west winds over the weekend

 -Elevated fire weather conditions expected across the northern
  Sacramento Valley late this week due a combination of low
  humidity and locally breezy winds with Friday into Sunday late
  morning being the worst forecasted period of conditions.

 -Probability of wind gusts > 30 mph:
*60-95% Friday across the Northern/Central Sacramento Valley
*50-85% Saturday across the Sacramento Valley and Delta.

.Changes from previous forecast...
 -Saturday`s winds have trended stronger with continued elevated
  fire weather conditions expected.

&&

.AVIATION...

VFR conditions with mostly clear skies will continue at TAF sites
over the next 24 hours. Surface winds generally below 12 kts,
except in the vicinity of the Delta and N San Joaquin areas,
where there will be periodic gusts around 15-20 kts until
06z Wed with lingering gusts through the Delta through 12z
Wed.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$