399
FNUS21 KWNS 171700
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1159 AM CDT Thu Jul 17 2025

Valid 171700Z - 181200Z

...Dry Thunderstorms...
Southerly flow on the eastern fringe of a mid-level low entering
southern California will aid in northward transport of monsoon
moisture into the Desert Southwest and Four Corners region. Isolated
dry thunderstorms are expected on the northern periphery of the
deeper moisture now across AZ and NM, where surface dewpoints are in
the upper 40s to 60s. The isolated dry thunderstorm threat was
contracted overall across the Great Basin, UT and western
CO/southwestern WY owing to latest model guidance, current position
of the monsoon moisture plume, alignment of remaining receptive
fuels as well as to account for recent precipitation footprints over
the last 48 hours.

..Williams.. 07/17/2025

.PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/

...Synopsis...
A shortwave trough will glance the Pacific Northwest bringing an
increase of westerly flow aloft across the Cascades into the Cascade
Gaps. As a result, areas of increased westerly downslope flow can be
expected along and just east of the Cascades in the Columbia River
Basin. Sustained winds 10-15 mph (locally higher in the Cascade
Gaps) overlap with afternoon relative humidity reductions to around
10-20 percent. An Elevated delineation was added with this outlook
to support this potential.

...Dry Thunderstorms...
A closed low off the coast of Baja California will bring moisture
northward across portions of the Southwest into the Great Basin. On
the fringe of this deeper moisture, isolated dry thunderstorm
potential will continue across portions of western Colorado into
western Wyoming, Utah, far southern Idaho and eastern Nevada. Here
precipitable water values drop to around 0.50" or less with more
limited coverage. Some mix of wet/dry thunderstorms will be possible
in central Utah and west-central Colorado but storm motions around
15-20 kts will likely yield little measurable precipitation.

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

$$