Nimbus, California Weather Forecast Discussion

079
FXUS66 KSTO 102108
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
208 PM PDT Wed Sep 10 2025
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.DISCUSSION...
.SYNOPSIS...
Active weather and cooler temperatures continue as a slow moving
system brings scattered shower and isolated thunderstorm chances
through Thursday, with the best potential Wednesday afternoon
through evening. A brief return to near normal temperatures and
drier weather is expected Friday into Saturday, with just some
lingering showers and thunderstorms possible for the Sierra south
of I-80 Friday afternoon. A quick moving system is expected to
move through Saturday night into early next week, bringing a
brief period of mainly mountain showers and cooling temperatures.
Dry weather with above normal temperatures returns by mid week.
&&
.KEY MESSAGES...
* TODAY - THURSDAY:
 - Periods of scattered showers and thunderstorms are
   expected to peak on Wednesday and continue through Thursday,
   before the system gradually exits to the east late Thursday
   night.
- Highest thunderstorm chances today are across the northern
   Coast Range, the mountains of Shasta County and the southern
   Cascades, then shifting to the Sierra crest Thursday.
- Slight chances for showers/thunderstorms exist through the
   remainder of the Valley/foothills, with highest potential,
   today and this evening around 10-20%. Best chances north of
   I-80.
- Today - This Evening:
- Today - Thursday:
- Probability of thunderstorms: 30-50% chances on Wednesday for
                                   northern Sacramento Valley/surrounding
                                   terrain & norther Sierra/southern
                                   Cascades
                                   15-30% chances on Thursday for
                                   northern Sacramento Valley/surrounding
                                   terrain & northern Sierra/southern
                                   Cascades
   - Probability of Rain > 0.1"  : 30-60%, highest along the Sierra/
                                   southern Cascades, Coastal Range,
                                   and Shasta County mountains.
- Well below normal temperatures and breezy onshore winds
   expected. Valley high temperatures in the mid 70s to low 80s
   with 60s to 70s anticipated at higher elevations.
* FRIDAY - SUNDAY:
 - As the longwave trough exits the region, a period of drier
   weather is expected to start the weekend with near normal
   temperatures returning. Lingering showers and thunderstorms are
   possible over the northern Sierra south of I-80
- High temperatures in the mid to upper 80s expected at lower
   elevations, with 70s to low 80s at higher elevations.
- A progressive weather system is expected to move through the
   region Sunday, bringing a slight chance for showers/isolated
   thunderstorms, with best potential for the northern Sacramento
   Valley/surrounding terrain.
.CHANGES FROM PREVIOUS FORECAST...
- Forecast rainfall amounts have trended lower the system early next
  week, with just some lingering showers on the Sierra crest Monday.
- Temperatures are trending above normal by Tuesday.
&&
.AVIATION...
Periods of MVFR/IFR possible in scattered showers/thunderstorms
generally north of Interstate 80 through 06z Thursday. Highest
thunderstorm chances in the Coast Range, Shasta County mountains,
and Sierra/southern Cascades. Otherwise, primarily VFR conditions
anticipated elsewhere. Breezy onshore winds continue, with gusts
15-20 kts across the Delta and adjacent Valley through 09z
Thursday.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$

NWS STO Office Area Forecast Discussion