199
FXUS66 KSTO 191930
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1230 PM PDT Sun Jul 19 2026

For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.

.KEY MESSAGES...

 - Elevated fire weather concerns in the northern Sacramento
   Valley and higher terrain due to isolated thunderstorm chances
   today and tonight.

 - Monsoonal moisture will continue to bring chances for wet/dry
   thunderstorms in the mountains through mid week.

&&

.DISCUSSION...

Current satellite has generally clear skies across California,
with a few scattered to broken clouds over portions of northern
California. A continued surge of monsoonal moisture today will
bring chances for showers and isolated thunderstorms this
afternoon, evening, and overnight for the Sierra. Best chances
will be along and south of I-80 along the crest. There does exist
a slight chance (10-15 percent) for an isolated shower or isolated
thunderstorm over parts of the Coastal range, northern Sacramento
Valley, southern Cascades, and through Shasta county this evening
and overnight. Confidence remains low on development as
instability and lift is lacking over this area of California. The
better instability and forcing needed for sustained thunderstorms
is over the Sierra and in Nevada. Dry thunderstorms are possible
in this region overnight as soundings show dry lower levels. Dry
thunderstorms will also be possible in the Sierra this afternoon
through the overnight hours. With the isolated wet/dry
thunderstorm chances there is an elevated fire weather concern for
the Sierra, southern Cascades, northern Sacramento Valley, into
the Coastal Range and Shasta county this evening through the
overnight.

There will be a continued surge of monsoonal moisture through mid
week, with the best chances for thunderstorms over the mountains
Tuesday through Wednesday. We will continue to monitor
thunderstorm chances and any further potential for dry
thunderstorms through the mid week timeframe.

Otherwise, temperatures will remain seasonal across the area
through the end of the week. Winds will be breezy at times near
the Delta and southern Sacramento Valley during the evening hours.

&&

.AVIATION...

VFR conditions through the TAF period, with slight chances for a
shower or isolated storm near RDD and RBL this afternoon and
evening. Otherwise, expect SCT to BKN clouds 21z through 12z for
areas along and north of Highway 50. MOD and SCK will see FEW to
SCT clouds this evening and overnight, with BKN at times.
Thunderstorm chances at the higher terrain overnight and into the
morning hours.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$