596
FNUS21 KWNS 131653
FWDDY1

Day 1 Fire Weather Outlook CORR 2
NWS Storm Prediction Center Norman OK
1153 AM CDT Wed Aug 13 2025

Valid 131700Z - 141200Z

CORRECTED FOR INCORRECT HEADLINE AND MISSING AREA

...CRITICAL FIRE WEATHER AREA FOR EASTERN IDAHO...

Adjustments were made to extend the Elevated across central Idaho.
While winds may not meet temporal criteria, new lightning fires were
reported overnight across this region with relative humidity
expected to drop to 15-20%.

Minor adjustments were made to the isolated dry thunderstorm chances
across Idaho and northern Nevada in alignment with trends in recent
high-res guidance.

See previous discussion below for more information.

..Thornton.. 08/13/2025

.PREV DISCUSSION... /ISSUED 0133 AM CDT Wed Aug 13 2025/

...Synopsis...
Widespread elevated to critical fire weather conditions are expected
today across a large swath of the Intermountain West. An upper wave
currently approaching the Pacific Northwest is expected to progress
quickly to the High Plains over the next 24 hours. As this occurs,
ascent ahead of the wave will induce surface pressure falls across
the northern Great Basin and northern Rockies. The low-level mass
response should promote widespread sustained winds in the 15-25 mph
range from the lee of the Cascades and Sierra Nevada into portions
of WY. Deep mixing should promote frequent gusts between 25-30 mph.
Transient swaths of 20+ mph winds will be possible across much of
the region, but confidence in sustained critical wind speeds remains
highest through the Snake River Plain in southern/eastern ID where
flow will be orographically enhanced. 06 UTC surface observations
across the Great Basin show very dry conditions already in place,
and diurnal heating of this dry air mass will support widespread RH
reductions into the 5-15% range. Recent fuel guidance shows
widespread ERCs above the 90th percentile across much of the region,
which should support the fire weather threat.

...Dry Thunderstorms...
A few early-morning thunderstorms are noted in GOES GLM data between
04-05 UTC across portions of NV (likely associated with ascent ahead
of a weak leading upper perturbation), though more substantial
thunderstorm activity is expected later this afternoon and evening
across the Great Basin. 00z soundings, water-vapor imagery, and the
recent convection all confirm that a plume of mid-level moisture is
in place ahead of the primary upper trough. As ascent and diurnal
heating increase through the afternoon, a swath of isolated to
scattered thunderstorms will likely develop from far eastern CA to
eastern ID/western WY. Very deep and well-mixed boundary layers,
coupled with storm motions near 20 knots, will promote mainly dry
thunderstorms. With receptive fuels in place, this convection will
pose a threat for new fire starts.

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