Applegate, California Weather Forecast Discussion

587
FXUS66 KSTO 211952
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1252 PM PDT Sun Sep 21 2025
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.SYNOPSIS...
Isolated to scattered shower/thunderstorm potential continue in
the mountains and northern Sacramento Valley today and tomorrow.
Warming and drying trend occurs Monday and Tuesday with breezy
northerly winds. Unsettled weather potentially returns mid-next
week.
&&
.KEY MESSAGES...
* TODAY - TUESDAY:
- Isolated showers and thunderstorms this afternoon and evening
   along the southern Cascades and coastal range, and south of HWY
   50 along the Sierra Crest (10-20%). No debris flow impacts are
   expected.
- Ridge builds in later today and Monday, with drying conditions
   and breezy northerly winds tonight into Monday. Breezy
   downslope winds expected along the Sierra Crest on Tuesday,
   with lingering breezy north winds in the Valley.
- Winds on both days have trended down with the latest forecast
- Briefly elevated fire concerns are possible when low RH values
      co-locate with the breezy winds. Confidence remains low in
      this occurring.
- There are non-zero chances (less than 10%) for light showers in
   the northern San Joaquin Valley and adjacent terrain overnight
   Tuesday into Wednesday due to a low pushing through southern
   California. Chances are even lower for isolated thunderstorms
   during the same time frame.
- Tuesday also sees widespread Moderate HeatRisk in the Valley
   and foothills as ridging increases temperatures.
* WEDNESDAY - SATURDAY:
- Temperatures cool rapidly mid-week, with a 5 to 10 degree
   temperature difference between the Tuesday and Wednesday
   forecast in most locations.
- NBM probabilities for thunderstorms remain about the same for
   Wednesday along most of the Sierra Crest south of I-80, around
   10-25%.
- Chances for thunderstorms on Thursday have increased along the
   Sierra crest, 10-25% north of HWY 50, 25-35% south of HWY 50.
- Lingering chances for isolated thunderstorms remain on Friday
   along the crest, around 10-20% and highest south of I-80.
- There is still some uncertainty in the path of the trough that
   would bring these isolated storms, and overall confidence is
   still low in spatial coverage and timing of storms. We will
   continue to monitor the latest guidance for any deviation in
   the system and potential for more widespread precipitation.
.AVIATION...
VFR conditions are forecast over the next 24 hours across TAF
sites. Isolated showers and thunderstorms will bring localized
MVFR/IFR conditions from 19Z-03Z today over the southern Cascades
and in the Sierra south of US 50. Periodically breezy winds will
develop after 09Z-12Z Monday, with northerly gusts of 15-25 kts in
the Valley and adjacent foothills, and northeast to east wind
gusts to 25-35 kts in the Sierra.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$

NWS STO Office Area Forecast Discussion