Robinsons Corner, California Weather Forecast Discussion

484
FXUS66 KSTO 082124
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
224 PM PDT Mon Sep 8 2025
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.DISCUSSION...
.SYNOPSIS...
This week will see active weather and cooler temperatures as a
slow moving system affects the region. Daily shower and scattered
thunderstorm chances continue through Thursday, with highest
chances across the northern Sacramento Valley and over the
mountains. The highest potential for thunderstorms is on
Wednesday. A brief return to near normal temperatures and drier
weather is expected Friday and Saturday, with the potential for
rain showers Sunday into Monday.
&&
.KEY MESSAGES...
* TODAY:
 - Below normal temperatures continue today alongside breezy
   onshore winds and steadily improving humidity recovery.
- A slow moving longwave trough offshore is slowly shifting
   inland and will continue a gradual eastward progression this
   evening into the week ahead.
* TUESDAY - THURSDAY:
 - Periods of scattered showers and embedded thunderstorms are expected
   through much of the week ahead as the aforementioned longwave
   trough moves onshore, and briefly stalls over interior NorCal
   on Wednesday.
- Chances of showers and thunderstorms spread across the area
   Tuesday. Highest thunderstorm chances are across the northern
   Sacramento Valley/surrounding terrain Tuesday, expanding to
   include the Sierra/southern Cascades Tuesday through Thursday.
   Wednesday has the highest potential for thunderstorms
- There are chances for showers/thunderstorms through the
   remainder of the Valley/foothills.
- Tuesday:
- Probability of thunderstorms: 20-30% across northern Sacramento
                                   Valley/surrounding terrain
   - Probability of Rain > 0.1"  : 60-80% for northern Sacramento
                                   Valley/surrounding terrain,
                                   25-45% elsewhere
- Wednesday - Thursday:
- Probability of thunderstorms: 20-40% chances on Wednesday for
                                   northern Sacramento Valley/surrounding
                                   terrain
                                   15-25% chances on Thursday for
                                   northern Sacramento Valley/surrounding
                                   terrain & Sierra/southern Cascades
   - Probability of Rain > 0.1"  : 30-60%, highest along the Sierra/
                                   southern Cascades
- While some uncertainty around timing/magnitude still persists,
   highest chances for nocturnal showers/thunderstorms is expected
   overnight overnight Tuesday-Wednesday AM.
- Well below normal temperatures and breezy onshore winds
   expected. Valley low temperatures in the mid 70s to low 80s
   with 60s to 70s anticipated at higher elevations.
.CHANGES FROM PREVIOUS FORECAST...
- Highest shower/thunderstorm chances trending toward northern
  Sacramento Valley/surrounding terrain and Sierra/southern
  Cascades on Wednesday.
- Rainfall amounts forecast have trended a little lower in the
  Valley.
&&
.AVIATION...
Generally VFR conditions expected at TAF sites through Monday
morning, although a 30-60% chance of MVFR/IFR in low stratus is
possible across the Delta and Sacramento Valley 05z-16z Tuesday.
Breezy winds continue, with gusts 15-30 kts at times. Strongest
winds expected until 06z Tuesday through the Delta and adjacent
Valley locations, as well as the Sierra. Chances for local
MVFR/IFR conditions from showers or thunderstorms over the
northern Sacramento Valley and Shasta County mountains Monday
afternoon through 11Z Tuesday.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$

NWS STO Office Area Forecast Discussion