000
FXUS66 KSTO 202204
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
304 PM PDT Fri May 20 2022

.Synopsis...
Warm and dry conditions continue into next week. Gusty north
winds diminish this evening. Dry conditions with lighter north
winds continue through the weekend, with increasing temperatures
and hot weather possible by the middle of next week.

&&

.Discussion...
A shortwave trough passing into the Great Basin brought strong
surface pressure north to northeast gradient. This gradient peaked
mid-day and is starting to weaken. Winds have largely peaked as
well but continue quite gusty across the area. Gusts reached as
high as 66 mph in the mountains, recorded 2.9 miles west of Alpine
Meadows, 64 mph at Eagle Peak. In the Valley there was a gust of
48 mph at Sacramento International Airport, 47 mph at Redding
Airport. Winds are expected to diminish by this evening. The Wind
Advisory remains in effect until 5 pm PDT for the Valley and
Delta.

The northerly downslope winds also brought poor overnight humidity
in the 20s and 30s to much of the area, and afternoon minimums in
the single digits. These when combined with generally cured fuels
below 2,500 feet brought critical fire weather conditions. A Red
Flag Warning continues until 8 pm. Many locations are seeing Red
Flag criteria conditions today. Numerous grass fires have been
reported in the Valley, such as the Dunnigan Fire, which at last
report grew to 120 acres. There also was the Golden Fire in the
foothills, near Camptonville and Bullards Bar. This fire was last
reported at 25 acres. Winds will continue northerly on Saturday,
but not be nearly as strong. Winds during the day Saturday will be
highest over the northern and central Sierra, where gusts to
20-25 mph are possible. Weaker northerly flow will continue
through Sunday. Humidity levels will remain quite dry and this
when combined with the winds will keep fire weather concerns
elevated levels through the weekend but not at the critical levels
we have seen today.

Temperatures Saturday will begin to trend upwards, with highs
several degrees warmer than today reaching into the upper 80s in
the Valley. Highs will reach into the low 90s. Another system
will drop into the Great Basin on Sunday increasing winds some late
Sunday into Monday. Temperatures are also expected to continue to
warm on Monday well into the 90s.

&&
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)...

Clusters are consistent in building the eastern Pacific ridge
over the region Tuesday and Wednesday, bringing hot temperatures
to the region. The latest NBM suggest Valley locations could
reach around 100 degrees both days. A period of moderate Heat Risk
continues from Sunday through Wednesday. Winds should generally
be light around the region with the ridge over us but at some
point the Delta breeze will likely kick in. Ensembles currently
favor this happening on Wednesday. A trough will deepening along
the coast by Thursday to help shift the high to the east and bring
cooler air to the interior. As the trough moves through it will
not only bring cooler temperatures for late next week but also a
chance of some showers. At this point shower chances look to be
north of I-80 for the mountains and over the northern half of the
Sacramento valley next Friday. European ensembles show increasing
run to run confidence in the northern portion of the area seeing
potential for some light precipitation.

&&

.AVIATION...

VFR conditions over the next 24 hours with gusty winds the main
weather concern today. Northerly wind gusts in the Valley from
20-35 knots thru 04Z Saturday. After 04Z, northerly Valley wind
gusts up to 20 knots possible.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM PDT this evening for Carquinez
Strait and Delta-Central Sacramento Valley in Glenn, Colusa,
Yuba, Northern Sutter, and Butte County Below 1000 Ft-Eastern
Mendocino NF-Eastern Portion of Shasta/Trinity NF-Northern
Sacramento Valley to Southern Tehama County Line Below 1000 Ft-
Northern San Joaquin Valley in San Joaquin and Stanislaus
Counties Below 1000 ft-Northern Sierra Foothills from 1000 to
3000 Ft. Includes portions of Shasta-Trinity and Butte Units-
Southeast Edge Shasta-Trinity NF and Western Portions of Tehama-
Glenn Unit-Southern Sacramento Valley in Yolo-Sacramento Far
Western Placer, southern Sutter and Solano County Below 1000 Ft.

Wind Advisory until 5 PM PDT this afternoon for Carquinez Strait
and Delta-Central Sacramento Valley-Mountains Southwestern
Shasta County to Western Colusa County-Northern Sacramento
Valley-Northern San Joaquin Valley-Southern Sacramento Valley.

&&

$$