508
FXUS66 KSTO 192006
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
106 PM PDT Sun Apr 19 2026
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.KEY MESSAGES...
- Dry weather with near to slightly above normal temperatures
today
- Storm system brings renewed precipitation chances in moderate
to heavy rain and mountain snow, thunderstorms, cooler
temperatures and breezy winds Monday through Wednesday
- Winter Storm Watch in effect from late Monday night through
Wednesday afternoon
&&
.DISCUSSION...
...Today...
Current GOES-West visible satellite imagery shows mostly to partly
sunny skies across interior northern California. The incoming
storm system can be seen on satellite over the eastern Pacific
ocean. Dry and warm weather will prevail across the area today.
Forecast highs are in the 70s to low 80s in the Valley and foothills,
and in the 50s to 60s in the mountains. These temperatures will
be trending near to slightly above normal for this time of year.
Southerly winds will gradually be increasing through the day today
as the storm system continues to approach the region and bring
impacts early to mid this week.
...Monday through Wednesday...
The upper level pattern will feature a low moving into California
bringing stormy conditions Monday through Wednesday of this week.
This storm will bring widespread rain, mountain snow,
thunderstorms, breezy south to southwest winds, and cooler
temperatures to interior northern California. Rain and snow will
be moderate to heavy at times, especially on Tuesday which is
looking like the brunt of the storm. A Winter Storm Watch has been
issued for the Sierra Nevada and southern Cascades above 5000 feet
from late Monday night through Wednesday afternoon. Snow levels
will initially be around 6000-7000 feet Monday night, lowering to
5500-6500 feet Tuesday and then down to 4500-5500 feet on
Wednesday. Mountain travel delays, chain controls, reduced
visibilities and snow covered roads are all possible.
For the lower elevations, rainfall will begin Monday and continue
through Wednesday with the heaviest on Tuesday. This will lead to
impacts such as slick roads, ponding of water on roadways, and
rises on creeks and streams. In addition to rain there is also the
threat for thunderstorms on Tuesday and Wednesday. Scattered
thunderstorms on Tuesday have the best chances for strong to
severe thunderstorm development. Potential hazards with these
thunderstorms that develop include lightning, gusty winds, heavy
rain, hail, funnel clouds and isolated weak tornadoes.
Precipitation tapers off late Wednesday. Check back frequently for
updates on this storm and always check the forecast and road
conditions before traveling!
...Thursday through Saturday...
Mostly dry weather returns to the region on Thursday behind the
passage of the storm system. Ensemble guidance is indicating the
potential for some additional mountain showers late in the week
and into next weekend with generally light precipitation.
Temperatures warm back up closer to normal for late April
climatology.
&&
.AVIATION...
General VFR conditions at TAF sites over the next 24 hours.
Increasing cloud cover around 00z Monday as a weather system moves
into the area, but no changes in flight categories in the next 24
hours. Southerly winds with gusts up to 25 kts in the northern
Sacramento Valley and foothills, and up to 30 kts in the mountains
through 06z Monday, then winds generally less than 12 kts
everywhere.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from late Monday night through Wednesday
afternoon for Lassen Volcanic National Park-Sierra Nevada of
Calaveras-Tuolumne-Southern Alpine Counties Above 5000 ft-Sierra
Nevada of El Dorado-Amador-Northern Alpine Counties Above 5000
ft Including Highway 50-Sierra Nevada of Sierra-Nevada-Placer
Counties Above 5000 ft Including Interstate 80-Sierra Nevada of
Tehama-Butte-Plumas Counties Above 3000 ft.
&&
$$
