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U.S. & Canada 00-UTC 48 Hour Surface Smoke Forecast
Map is in operation from early April through October 31
U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 251632
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1132 AM CDT Tue Aug 25 2026
Valid 251700Z - 261200Z
No changes were made to the ongoing forecast. Yesterday afternoon,
dry thunderstorms (accumulating precipitation largely below 0.15")
passed over central-northern NV, northeastern ID, southeastern OR,
and southern ID with many new fire starts visible by satellite
imagery. Elevated to locally critical fire weather conditions will
overlap some of these new starts this afternoon, further
exacerbating the fire environment and provoking any
lightning-induced holdovers to emerge.
The IsoDryT threat will shift northward today, extending from the
Wallowa Mountains in northeast OR into southwest MT where a dry
sub-cloud layer and fast storm motions will limit greater
precipitation efficiency. Receptive fuels (80-95th percentile ERCs)
will support new ignitions within the highlighted region. More
recovered fuels across portions of southern ID, northeastern NV, and
northwestern UT precludes a southward expansion of the IsoDryT,
though lightning ignitions cannot be ruled out where pockets of
drier fuels exist.
Offshore flow will begin this evening into the overnight hours
across LA/Ventura/Santa Barbara counties in southern California,
promoting elevated fire weather concerns as fuels grow increasingly
more receptive. Please see the previous discussion for more details.
..Elizalde-Garcia.. 08/25/2026
.PREV DISCUSSION... /ISSUED 0101 AM CDT Tue Aug 25 2026/
...Synopsis...
A mid-level wave embedded in broader southwest flow on the western
periphery of a high-amplitude upper ridge is expected to move into
the northern Rockies through today. This feature along with daytime
destabilization will aid in isolated thunderstorm development from
the Wallowa Mountains in northeast OR into central ID and far
southwest MT. Dry southwest flow in the wake of this feature will
bring a fire weather concern to portions of northeast CA, northwest
NV and southeastern OR. A weak offshore pressure gradient in the
evening and overnight hours will bring dry and breezy conditions and
a fire weather threat to portions of Southern CA.
...Northeastern Oregon, Central Idaho Mountains and far southwestern
Montana...
High-based convection is expected this afternoon from far
northeastern OR mountains, eastward into portions of the northern
Rockies as the mid-level wave moves into the region amid increasing
afternoon instability. Inverted-V forecast soundings, PWAT values of
only 0.5" to 0.8" and high surface dew point depressions (surface
dewpoints in the 30s to 40s F) will likely support mostly dry
isolated thunderstorm activity this afternoon. Fuels remain dry
receptive as evidenced by new recent lightning ignitions across
northeastern CA and northwestern NV, with ERC values in the 90-95th
percentile range stretching northeastward into central ID.
...Northeastern California into Northern Great Basin...
Modest southwest winds aloft, an increasingly dry boundary layer and
an efficient daytime mixing environment will bring gusty southwest
winds to portions of northeastern CA into the northern Great Basin
for several hours this afternoon. Southwest winds of 10-15 mph with
higher gusts and RH as low as 15 percent will result in elevated
fire weather conditions. Locally critical fire weather concerns will
exist where winds briefly reach 20 mph. Recent lightning and
resultant new wildfires across northeastern CA and northwestern NV
will be exposed to this adverse fire weather environment this
afternoon.
...Southern California...
An elevated fire weather threat will evolve this evening and
overnight across portions of southern California as offshore flow
develops amid an increasingly receptive fuelscape. Offshore winds of
15-25 mph are expected in favored terrain gaps and downslope regions
of LA/Ventura/Santa Barbara counties as RH falls to as low as 15
percent, primarily this evening into early Wednesday morning.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 251914
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0214 PM CDT Tue Aug 25 2026
Valid 261200Z - 271200Z
The Isolated Dry Thunderstorm risk was expanded slightly eastward to
include more of western Montana based on the latest guidance.
HREF/REFS depict 50-60% probabilities of thunderstorms across
southwest Montana into the Yellowstone Country on Day 2/Wednesday.
Forecast soundings depict a dry sub-cloud layer, sufficient
instability, and 20-30 kt LCL-EL winds indicating limited
precipitation efficiency. A recently receptive fuelscape with active
fires within the higher terrain warrant an expansion of dry
thunderstorm highlights where lightning ignitions are possible. The
rest of the forecast remains on track, see the previous discussion
for more information.
..Elizalde-Garcia.. 08/25/2026
.PREV DISCUSSION... /ISSUED 0102 AM CDT Tue Aug 25 2026/
...Synopsis...
An upper-level trough impinging upon the Pacific Northwest will
usher in increasing southwesterly flow and dry conditions to
portions of the interior Northwest and northern Great Basin. The
trough and afternoon destabilization will also bring a dry
thunderstorm threat to the portions of the northern Rockies
Wednesday afternoon. Farther south, an offshore pressure gradient
becomes established this evening and overnight hours leading to fire
weather concerns across portions of southern CA.
...Northern Rockies into northern Washington...
The upper-level trough nearing the Pacific Northwest will boost
southwest flow aloft while residual monsoon moisture lingers across
the northern Rockies. Daytime instability over complex topography in
addition to diffuse forcing for ascent will likely bring a broad
area of isolated high-based showers and thunderstorms to the
northern Rockies in western MT and northern ID as well as across
northern WA. PWAT values will generally be below 0.80" while a dry,
sub-cloud boundary layer and high surface dew point depressions
inhibit rainfall accumulations. Fuels remain receptive with new
ignitions possible Wednesday afternoon from this thunderstorm
activity.
...Columbia Basin southward towards the northern Great Basin and
Northeastern California...
Increasingly dry southwest flow as deeper monsoon moisture pushes
eastward is expected to bring elevated fire weather concerns to much
of the Interior Northwest and northern Sierra Nevada Wednesday. An
evolving well-mixed and dry boundary layer by peak afternoon heating
will support enhanced southwest winds at the surface of around 15
mph. These winds coupled with RH as low as 10 percent amid dry fuels
will promote elevated fire weather conditions across the region. A
locally critical fire weather concern may emerge across northeastern
CA into southeastern OR where sustained southwest winds of 20 mph
may occur at times.
...Southern California...
A multi-day elevated fire weather threat will continue for portions
of southern CA late Wednesday into early Thursday morning as
offshore/sundowner winds develop with supportive surface high
pressure across the Great Basin. Offshore winds of 15-25 mph are
expected in favored terrain and downslope regions as RH falls to as
low as 15 percent beginning Wednesday evening into early Thursday
morning. Elevated highlights were introduced into portions of
LA/Ventura/Santa Barbara counties.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 252200
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0500 PM CDT Tue Aug 25 2026
Valid 271200Z - 021200Z
...Synopsis...
An upper ridge will gradually translate eastward into the northern
Plains as a mid-level shortwave trough progresses through the
Pacific Northwest on Day 3/Thursday. Meanwhile, large-scale ascent
will overspread the Northern Rockies into central Montana, promoting
thunderstorm potential where dry fuels exist. A cold front will
sweep across the Columbia Basin, bringing strong winds and modestly
low RH values to a drought-stressed environment with numerous
ongoing wildfires on Day 3/Thursday. Strong southwest-westerly flow
will continue across the northwestern CONUS into the weekend, with
embedded disturbances within persistent upper troughing and along
the northern periphery of the flattening ridge. Long term guidance
suggests a secondary shortwave trough could enter the Northwest and
contribute to the breakdown of the upper ridge atop the Four Corners
this weekend. As a result of the upper pattern, fire weather
concerns will likely continue through the forecast period across the
parts of the Northwest, Great Basin and Northern Rockies. However,
low predictability and poor agreement among ensemble clusters
precludes additional probabilities beyond Day 5/Saturday.
...Dry Thunderstorms...
The arrival of the next upper-level wave will bring additional
opportunities for afternoon thunderstorms across portions of the
Northern Rockies and Montana plains on Day 3/Thursday. A dry
boundary layer and fast storm motions will favor evaporation and
less precipitation efficiency, raising concerns for
lightning-induced ignitions within an increasingly receptive
fuelscape. 10% Dry Thunderstorm probabilities were introduced on Day
3/Thursday, though may need to be confined in future outlooks where
multiple days of an overlapping thunderstorm threat could increase
recoveries.
...Northwest, Northern Great Basin and Northern Rockies...
A drier southwest flow pattern will bring a multi-day fire weather
threat to portions of the northwestern U.S., with fire weather
concerns extending eastward into the Montana plains later this week.
40% Critical probabilities have been maintained with minor
adjustments for Days 3-5/Thursday-Saturday, and introduced across
north/central Montana on Day 4/Friday. West to southwest winds of
15-20 mph and afternoon relative humidity between 15-20 percent will
bring daily elevated fire weather concerns, potentially impacting
nascent wildfires born from thunderstorm activity early in the
forecast period. Critical fire weather conditions with winds of 20+
mph are likely but only in localized areas, particularly from
northeastern CA into far northwestern NV and southeastern OR on Day
3/Thursday.
...Southern California...
Above average daytime temperatures and poor humidity recoveries are
forecast across portions of southern California through the
week/early weekend. Offshore flow will present overnight/early
morning periods of gusty winds and critically low RH values in Santa
Barbara/Ventura/LA counties amid very dry fuels, raising concerns
for locally elevated fire weather conditions. As such, 40% Critical
probabilities were introduced on Days 3-4/Thursday-Friday.
..Elizalde-Garcia.. 08/25/2026
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