922
FXUS66 KSTO 262019
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
119 PM PDT Fri Jul 26 2024

.SYNOPSIS...
Less hot with a cooling trend into the weekend. Critical fire
weather conditions today in the central and northern Sacramento
Valley and adjacent terrain with low humidity and gusty southerly
winds.

&&

.Key Points...
- A Red Flag Warning is in effect for much of the central and
  northern Sacramento Valley and northern foothills thru 11 PM
  tonight.
- Cooling trend into the weekend with gradual warming trend by the
  middle of next week.

&&

.Discussion...
The recent trend of widespread triple digit temperatures in the
Valley and foothills begins to end today; currently, temperatures
across the Valley and foothills are in the mid 80s to low 90s, with
high temperatures in the Valley and foothills expected to range
today from the low 90s to just over 100. Temperatures are expected
to cool even more dramatically tomorrow, over 10 degrees in some
locations, due to an upper low passing over the area. While the
low has caused some of the recent gusty winds, the system itself
is fairly dry and is not expected to bring any precipitation to
the area. Winds themselves will continue to trend down as well,
with conditions becoming lightly breezy over the weekend, as
opposed to the gusty winds we`ve been experiencing.

Fire weather conditions in general are expected to improve over the
weekend, though a Red Flag Warning remains in effect until 11 PM
tonight. Daytime and overnight relative humidities this weekend
will be higher in the Valley, temperatures (as previously
mentioned) will be cooler, and winds will trend down. However,
higher elevations will see less relief in the form of elevated
humidities, and fuels are still quite dry, so it will remain
important to practice fire safety during this time. Finally, as
quickly as the "cooler" weather arrived, it will be replaced by a
gradual warming trend early next week. It is however, important
to note that there is some ensemble and cluster disagreement over
when exactly the low will move on, and how strong it will have
remained by that point, meaning that temperatures will be slow on
the road back to above normal for the time of year. Monday, high
temperatures are expected to remain primarily in the 80s and 90s,
only slightly warmer than over the weekend. //SP

&&

.EXTENDED DISCUSSION (Tuesday THROUGH Friday)...
As we move into the remainder of next week, temperatures will
continue their Sisyphean climb back up to normal and above normal
conditions. By Thursday, clusters and ensembles seem to be in good
agreement that ridging will begin to encroach on the area once
again, bringing back the near to above normal temperatures in
earnest. Temperatures look to remain around the mid 90s to low
100s in the Valley through the end of next week, though there is
some uncertainty as we head into the weekend. Otherwise, warm dry
weather is expected through next week, with temperatures gradually
increasing and daytime relative humidity gradually decreasing. //SP

&&

.AVIATION...
VFR conditions over interior NorCal next 24 hrs except local
MVFR/IFR possible in haze/smoke vicinity of wildfires. In Central
Valley, areas of southerly surface wind 10-15 kts, with gusts up
to 25 kts until around 10z. In the vicinity of the Delta,
southwesterly surface wind 15-25 kts with local gusts to 35 kts.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 11 PM PDT this evening for Burney Basin
and Northeast Plateau in Shasta County Including Northwest
Lassen NF north of Lassen NP-Central Sacramento Valley in Glenn,
Colusa, Yuba, Northern Sutter, and Butte County Below 1000 Ft-
Northern Sacramento Valley to Southern Tehama County Line Below
1000 Ft-Northern Sierra Foothills from 1000 to 3000 Ft. Includes
portions of Shasta-Trinity and Butte Units-Northern Sierra
Including Lassen NP and Plumas and Lassen NF/S West of the
Sierra Crest (West of Evans Peak-Grizzly Peak-Beckworth Peak).

&&

$$