Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 170514
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1010 PM PDT Sun Jul 16 2017

.SYNOPSIS...
Hot and dry today with triple digit temperatures in the Valley.
Cooling to near seasonal normals by Tuesday with breezy winds.

&&

.DISCUSSION...
Onshore flow increasing to 3 mbs but cooling has been limited due to
a suppressed marine layer, about 800 ft on the Ft Ord Profiler.
However, developing/deepening low pressure off the B.C. Coast will
suppress the Desert SW ridge over Norcal allowing migratory short
waves to pass through Norcal Mon/Tue under SW flow aloft. This will
bring some synoptic cooling to the region, about 3-6 degrees on Mon,
and another 6-8 degrees or so on Tue over most locales.

Prevailing SW flow will be dry and inhibit CB genesis in our CWA,
but the passing short waves could kick up some SW wind gusts over
portions of our NErn Shasta Co zone. Thus, RFW products are in
effect for the Burney Basin area.

.Previous Discussion...
Temperatures have been trending 3 to 7 degrees above yesterdays`s 2
pm readings. Today will be the peak of the heat with most areas
topping out around 105 degrees within the valley with the north end
of the valley near 110 degrees. Mountains will top out in the 80s
and 90s. A light north wind persists but will reverse direction by
late afternoon into the early evening hours within the valley.
Breezy conditions will likely develop through the Delta this evening.

The heat will be short lived as the high pressure shifts to the
east and a weak trough develops over the west coast. This will
cool temperatures Monday and Tuesday back to near seasonal
normals by Tuesday. There will also be decent flow through the
Delta each day along with the return of the marine layer along
the coast.

&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)

Seasonal temperatures will remain through at least Friday as a
trough remains along the west coast. Temperatures will warm-up
some across interior NorCal next weekend but do not look excessive
for the time of year. The trough over the eastern Pacific weakens
a little while high pressure strengthens some. That should help
to suppress the marine layer. Most of the Central Valley will see
highs of 97-105 next weekend. Monsoon moisture is expected to
remain to the south and east of the region.

&&

.AVIATION...

VFR conditions next 24 hours. Onshore flow increases with gusts 20-
25 kts in the Delta. Limited cooling due to suppressed marine layer.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 5 PM PDT this afternoon for Central
Sacramento Valley in Glenn, Colusa, Yuba, Northern Sutter, and Butte
County Below 1000 Ft-Eastern Mendocino NF-Lake County Portion of
Lake-Napa-Sonoma Unit-Northern Sacramento Valley to Southern Tehama
County Line Below 1000 Ft-Southeast Edge Shasta-Trinity NF and
Western Portions of Tehama-Glenn Unit.

Red Flag Warning valid from 2 PM to 8 PM PDT Monday for Burney Basin
and Northeast Plateau in Shasta County Including Northwest Lassen NF
north of Lassen NP.


&&

$$



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