Vallecito, California Weather Forecast Discussion

609
FXUS66 KSTO 151954
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1254 PM PDT Mon Sep 15 2025
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.DISCUSSION...
.SYNOPSIS...
Dry weather with above normal temperatures in the 90s through
Wednesday. Clouds and a few showers and isolated thunderstorms
moves in Thursday into the weekend to bring cooling trend.
&&
.KEY MESSAGES...
* TUESDAY - WEDNESDAY:
 - Ridging aloft brings dry conditinos and above normal
   temperatrures and areas of moderate heat risk.
* THURSDAY - SATURDAY:
- Moisture from tropical system Mario will move into area bring
   clouds and chance of moisture to all areas. No strong forcing
   with the moisture so likely most activity in higher terrain but
   enought moisture for light showers or even a thunderstorm in
   the valley. Main time period looks to be Thursday night through
   Saturday.
- Elevated fire concerns will be highest Thursday night into
   Friday before moisture deepens and humidities increase.
.CHANGES FROM PREVIOUS FORECAST...
- No major changes except to introduce slight chance of thunder
   to southern valley locations Thursday night.
&&
.AVIATION...
VFR conditions and clear skies expected at interior northern
California TAF sites next 24 hours. Surface winds generally less
than 12 kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$

NWS STO Office Area Forecast Discussion