949
FNUS28 KWNS 202117
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0415 PM CDT Thu Jun 20 2024

Valid 221200Z - 281200Z

At least low chances of wetting rains are expected to continue into
early this weekend across portions of the Southwest and southern
Rockies within a moisture plume associated with the remnants of
Alberto. Further west and north across the Great Basin and the rest
of the Desert Southwest, hot and dry conditions will be present
under a mid to upper-level ridge D3/Saturday.

The pattern will begin to shift by D4/Sunday, as a Pacific mid to
upper-level shortwave trough and jet max in its base move onshore
near northern WA. An associated dry, cold front will traverse WA and
OR Sunday. Both a tightening surface pressure gradient and momentum
transfer from aloft within subsidence behind the trough axis will
lead to breezy, downslope flow developing across the Cascades and
into the Columbia Basin. Fuel states are expected to deteriorate
within the aforementioned regions. Therefore, at least low critical
probabilities remain in the forecast. In addition, if model trends
continue to suggest slightly stronger mid-level flow over WA, a
small area of 70 percent critical probabilities may be introduced in
subsequent forecasts within the lower fuel moisture content of the
southwestern Columbia Basin of WA. Ahead of the cold front across
the Upper Snake River Plain, warm, dry, and breezy conditions are
anticipated within a well-mixed air mass. Fuels across this region
are less receptive, but any ignitions may have the opportunity to
spread quickly, as sustained speeds at or above 20 mph persist for
several hours there in conjunction with single-digits RH.
Furthermore, modest flow aloft and a tightening pressure gradient
over southern ID behind the cold front D5/Monday will continue to
support low critical probabilities within the Upper Snake River
Plain.

Confidence in the large-scale pattern decreases slightly D6-D8,
although hot and dry, fuel-curing conditions appear likely over the
Southwest and most of the Great Basin under the influence of upper
ridging. Critical probabilities could return to the extended periods
mid to late next week, as another north Pacific mid to upper-level
low moves onshore.

..Barnes.. 06/20/2024

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

$$