057
FXUS66 KSTO 120749
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1249 AM PDT Mon Aug 12 2024

.SYNOPSIS...
Cooler temperatures and increasing humidity, with periods of
breezy onshore winds this week.

&&

.Discussion...
With clear skies tonight, some have been able to see the Northern
Lights, including some Alert California cameras up near Redding.
Reports of sights of the lights have come in from as far south as
Chico tonight. Some folks have seen portions of the Perseid
meteor shower as well. Otherwise, the influence of the Delta
Breeze can be felt in much of the southern Sacramento and northern
San Joaquin Valleys tonight. Temperatures as of midnight were
already in the low to mid 60s in the greater Sacramento
metropolitan area, and are expected to get into the high 50s in
areas later in the early morning.

The current onshore flow will continue into tomorrow, moderating
temperatures throughout the Valley. Highs in the area will range in
the mid 80s to the low 90s in the Valley, with mid 60s to the mid
80s at higher elevations. This general temperature trend will
continue through the end of the week, with slight variations
throughout. However, conditions are expected to remain below
climatological normal throughout the short term forecast period.

&&

.EXTENDED DISCUSSION (Friday THROUGH Monday)...
From late week into next weekend, cluster analysis is showing a
high degree of confidence in the expected upper level pattern,
with nearly all ensemble membership indicating a deepening trough
off the coast of the Pacific Northwest. While a small portion
(~15%) depicts a more progressive trough, the vast majority (~85%)
indicates a building ridge over the south-central CONUS, blocking
the trough in the Pacific Northwest vicinity into the weekend.
While the expected orientation of the trough should allow for
incremental gains in humidity recovery, deeper moisture advection
for precipitation is not anticipated at this time. Rather, this
pattern will look to allow a continuation of below normal
temperatures from Friday into next weekend. Additionally, some
breezier conditions will be possible as the trough deepens.
Resultant current probabilities of wind gusts exceeding 25 mph
outside of the Delta vicinity do increase to around 20% to 40% on
Friday and Saturday.

&&

.AVIATION...
VFR conditions over interior NorCal next 24 hrs except isolated
MVFR in HZ/FU possible at times in vicinity of fires.
Southwesterly winds 10-15 kts with gusts 15-20 kts until 10z
today, then again between 18z today and 10z Tuesday. Otherwise,
wind below 12 kts. In and around the Delta, southwesterly surface
winds sustained 15-20 kts with gusts 20-30 kts at times.

&&

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

&&

$$