184
FXUS66 KSTO 052108
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
208 PM PDT Tue May 5 2026

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


.KEY MESSAGES...

 - Lingering mountain shower and thunderstorm chances into this
   evening, with drying conditions midweek.

 - Hot and dry conditions are expected to develop end of the week
   with widespread Minor HeatRisk Thursday and Friday.

 - Widespread Moderate HeatRisk Saturday into Tuesday, with
   triple digit and daily record highs possible.

&&

.DISCUSSION...

...Today...

Latest RADAR shows just a few light returns over the Sierra south
of Hwy 108. Convective Allowing Models(CAMs) suggest some showers
showers and possibly a couple isolated thunderstorms around the
I-80 corridor from around 3 to 6 pm, potentially a few more before
midnight. Precipitation will be generally light but there may be
a few pockets of moderate rainfall at times. Snow levels are
expected to remain above 9000 feet, so all but the high peaks
should see precipitation in the form of rain. Showers should be
ending by around midnight. Highs this afternoon are 5 to 10
degrees below normal, in the upper 60s to low 70s.

...Wednesday through next Tuesday...

Wednesday is expected to be dry with near normal high
temperatures as the cool low pressure system exits and eastern
Pacific high pressure ridging shifts into the region. This is the
beginning of an extended period of dry and warm weather. Conditions
continue to warm as we move into weekend into early next week.
Minor HeatRisk is expected across the Valley Wednesday, becoming
more widespread and extending into the foothills and mountains by
the end of the week. Some areas of Moderate HeatRisk are expected
in the Valley by Saturday, expanding to include the foothills by
Sunday. The NBM currently indicates a 60-90% chance of high
temperatures greater than 90 degrees in the Valley Saturday,
75-95% on Sunday.

Minimum RH values trend lower through the week as well,
dropping into the 20s and teens by the weekend. This will coincide
with a period of breezy north winds that develops on Saturday
which could lead to elevated fire weather conditions in the
central Sacramento Valley. Forecast gusts are between 15 and 25
mph.

Looking into early next week, models (including the NBM 5.0)
continue to show at the potential for triple digit temperatures
as ridging amplifies over the region. Some daily high temperature
records are in jeopardy. The NBM continues to indicate a 50 to
70% chance of 100 or greater in the northern San Joaquin Valley
and portions of the central Sacramento Valley next Monday and
Tuesday. There may be some Delta breeze to give influenced areas a
slight break for overnight lows.

&&

.AVIATION...
Scattered low clouds and ceilings will lead to MVFR conditions
this morning in the Valley through roughly 20Z today. VFR
conditions through 09Z Wednesday, before scattered low clouds
redevelop in the Valley leading to MVFR conditions until around
21Z Wednesday. Low chance (10-15%) of isolated mountain
showers/thunderstorms developing this afternoon along the Sierra
crest. Otherwise, surface winds will generally be 12 kts or less.


&&

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

$$