000
FXUS66 KSTO 312141
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
241 PM PDT Sat Jul 31 2021

.SYNOPSIS...
Late day mountain thunderstorm chances expected through the
weekend. Near normal temperatures will continue through the rest
of the weekend into next week.

&&

.DISCUSSION...
Upper level ridging is weakening, with a little cooler onshore
flow spreading in. South to west winds are generally gusting up to
15 to 20 mph, locally up to 30 mph in the Delta. Temperatures are
less hot this afternoon by 5 to 10 degrees compared to 2 pm
yesterday. For the northern Sacramento Valley it was seasonably
hot at 100 for Redding, 97 for Red Bluff.

Monsoonal moisture continue to bring afternoon and evening shower
and thunderstorm chances. The main areas of development are around
Lassen National Park/Burney Basin and the Sierra south of Highway
50. Shear is limited and storms are tending to pop up and collapse
fairly quickly. Some brief heavy rain and small hail are possible
into this evening, though, so be prepared if outdoors or driving
in the area. Strongest storms so far have been further to the
south in Yosemite or east of the crest. One last afternoon of
thunderstorms is possible on Sunday, followed by drier weather for
the rest of the week as monsoonal moisture shifts to the east.

Southwesterly flow continues next week with near normal
temperatures.

&&

.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...

Clusters and ensemble guidance continue to favor dry, southwest
flow aloft through the end of next week with an upper level ridge
parked over the Desert Southwest / southern California and a
trough off the West Coast. National Blend of Models has a moderate
spread in the 25th to 75th percentile temperatures by Thursday --
96 to 103 deg F for KRDD and 93 to 100 deg F for KSAC. A few
clusters hint at the shortwave trough clipping far northwest
California late next week, though still plenty of uncertainty this
far out. Overall generalization for mid/late next week has
temperatures within about 5 deg F of normal with occasional breezy
conditions around the Delta. // Rowe

&&

.AVIATION...

VFR conditions expected at the TAF sites the next 24 hours. Areas
of smoke near the Dixie and McFarland fires will bring localized
MVFR conditions. Southerly winds 7-15 knots, locally stronger in
the Delta region. Isolated-scattered showers and thunderstorms
over the mountains.
&&

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

$$