398
FNUS28 KWNS 072217
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0515 PM CDT Fri Aug 07 2026

Valid 091200Z - 151200Z

...Synopsis...
A mid-level shortwave will move into the northern High Plains by Day
3/Sunday within a deamplifying upper ridge. This will leave a zonal
flow pattern in place across the northern CONUS for early next week
with lingering fire weather concerns over portions of the
Intermountain West. A dry thunderstorm threat will likely persist
across portions of the Great Basin and central Rockies on Days
3-4/Sunday-Monday on the northern fringe of deeper monsoonal
moisture across the Desert Southwest.

...Days 3-4/Sunday-Monday...
...Northern Intermountain West and adjacent northern High Plains...
A mid-level short wave should round the flattening upper ridge over
the West, affecting the Northern Rockies on Day 3/Sunday. A
tightening surface pressure gradient along the southern Cascades and
adjacent terrain will promote gusty surface winds within a dry
boundary layer. Breezy west winds up to 15 mph (locally 20 mph) and
low relative humidity will combine with increasingly receptive fuels
across the broader northwestern CONUS. As such, 40% Critical
probabilities were largely maintained for this broad region. On Day
4/Monday, stronger upper-level flow will continue across the
flattened ridge, sustaining a pattern of dry and breezy conditions
atop exceptionally dry fuels. 40% Critical probabilities have been
expanded to account for a broader, prolonged fire weather threat.

...Southern Sierra, central Nevada and portions of Utah...
High based convection is likely to evolve Days 3-4/Sunday-Monday on
the northern periphery of deeper monsoonal moisture. PWATs ranging
of 0.60-0.80" and daytime instability will likely lead to isolated
high-based thunderstorms across portions of the southern Sierra
Nevada, upper Great Basin, and northwestern CO on Day 3/Sunday. This
threat will persist across the northern Great Basin, southwestern
WY, and northwestern CO on Day 4/Monday. Uncertainty remains in the
strength and residence time of the monsoon surge, though a mix of
wet/dry thunderstorms atop a drought-stressed and significantly dry
fuel environment raises concerns for lightning-induced ignitions; as
a result, 10% Dry Thunderstorm probabilities have been expanded on
Day 3/Sunday and introduced on Day 4/Monday.

...Days 5-8...
On Day 5/Tuesday, 40% Critical probabilities were expanded across
southeastern OR, northeastern CA, and portions of the Great Basin
where forecast confidence is higher in a continuation of dry and
breezy conditions. Extended ensemble guidance depicts a pattern
change across the western CONUS late next week, with offshore
troughing bringing the potential for surging monsoonal moisture and
thunderstorms to northern California and the Pacific Northwest.
However, predictability is too low in the long term to introduce any
probabilities at this time.

..Elizalde-Garcia.. 08/07/2026

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

$$