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000
FNUS21 KWNS 221650
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1150 AM CDT Tue Aug 22 2017

Valid 221700Z - 231200Z

...Portions of Northern CA into Southern/Central OR and Far
Northwestern NV...
Some minor adjustments have been made to the ongoing isolated
dry-thunderstorm area based on short-term guidance, but the overall
forecast rationale remains unchanged. While some rainfall will be
possible near the strongest cores, widespread wetting rains are not
expected and thunderstorm activity will pose a threat of ignitions
given the dry fuels in place. See the previous discussion below for
more details.

..Dean.. 08/22/2017

.PREV DISCUSSION... /ISSUED 0145 AM CDT Tue Aug 22 2017/

...Synopsis...
Upper ridging will remain prominent over much of the western CONUS
today, while an upper low located off the coast of southern/central
CA moves little. Mid-level monsoonal-related moisture will advance
northward along the Sierras into the southern Cascades and vicinity
along the northern periphery of the upper low this afternoon.

...Portions of Northern CA into Southern/Central OR and Far
Northwestern NV...
Isolated to scattered thunderstorms will develop by this afternoon
and continue through the evening hours across portions of northern
CA into southern/central OR. Terrain-driven circulations will likely
be the primary impetus for convective initiation. Precipitable water
values around 0.7 to 1.0 inch and modest (~15-20 kt) mid-level
southwesterly flow along the Sierra/Cascade crest will likely allow
for a mix of wet/dry thunderstorms. A dry antecedent low-level
airmass coupled with diurnal heating will act to lower RH values
across this region, which should limit the potential for wetting
rainfall outside of the heaviest thunderstorm cores. Strong and
erratic outflow winds will be possible with any thunderstorm in this
environment. Fuels also remain generally dry to very dry and
receptive to large fire starts. Therefore, an isolated dry
thunderstorm area continues with no changes across northern CA into
southern/central OR and far northwestern NV.

...Please see www.spc.noaa.gov/fire for graphic product...

$$