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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 311458
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0958 AM CDT Fri Jul 31 2026
Valid 311700Z - 011200Z
...NO CRITICAL AREAS...
Upper-level ridging is currently centered over western Montana,
promoting a continued dry airmass and warm temperatures across the
Inland Northwest this afternoon. Satellite imagery depicts heavy
wildfire smoke blanketing much of the region, which could limit
broader daytime high temperatures to 80-90F. At peak heating, RH
values will decline to around 15% where ERCs are exceeding the 90th
percentile. A lesser spatial extent of sustained winds greater than
15 mph preclude an introduction of Elevated highlights; however,
areas of terrain-influenced winds exceeding 15 mph could promote
locally elevated fire concerns. In addition, an extended burning
period is expected, as minimal overnight humidity recoveries are
forecast over the Columbia Basin and portions of eastern Oregon.
These conditions may further exacerbate numerous wildfires across
the region, especially as an upper trough begins to move onshore
late in the forecast period (after 06z) leading to robust and
expansive fire weather concerns on Day 2/Saturday (see the Day 2
Fire Weather Outlook). The rest of the forecast remains on track,
see the previous discussion for more information.
..Elizalde-Garcia.. 07/31/2026
.PREV DISCUSSION... /ISSUED 0216 AM CDT Fri Jul 31 2026/
...Synopsis...
A potent upper-level trough will begin to move onshore over the
Pacific Northwest tonight, with upper-level ridging ahead of this
trough extending from the Desert Southwest into the northern
Rockies. An embedded, mid-level shortwave trough is forecast to
precede the larger trough and move from northern California into the
northern Rockies through this afternoon while weakening. Hot, dry,
and locally breezy conditions are likely across much of the West,
especially the Intermountain West, this afternoon, with locally
elevated fire weather conditions possible. The lack of widespread,
sustained surface winds above 15 mph precludes the inclusion of
Elevated highlights, however.
Isolated, drier thunderstorms are possible across portions of
central/eastern Idaho and southwest Montana this afternoon and
evening, but the latest SREF/HREF guidance continues to suggest less
than a 20% chance and generally less than a 10% chance of
thunderstorms. Somewhat greater chances for thunderstorms exist
farther east into portions of Wyoming, but this activity is likely
to be wetter and over less receptive fuels. Elsewhere, monsoonal
thunderstorms remain likely over portions of southeastern Arizona
and along/east of the Continental Divide in Colorado and New Mexico.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 312002
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0302 PM CDT Fri Jul 31 2026
Valid 011200Z - 021200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE COLUMBIA
BASIN IN CENTRAL/SOUTHEASTERN WASHINGTON AND NORTHERN OREGON...
...CRITICAL FIRE WEATHER AREA FOR EASTERN OREGON AND FAR WESTERN
IDAHO INTO EASTERN WASHINGTON...THE IDAHO PANHANDLE...AND
NORTHWESTERN/NORTH-CENTRAL MONTANA...
***Dangerous fire weather conditions are expected across
central/southeastern Washington and northern Oregon on Day
2/Saturday.***
...Day 2/Saturday Update...
The Extremely Critical risk area has been expanded into northern
Oregon to account for downslope enhanced southwest to westerly
surface winds and critically low RH amid a very receptive fuelscape.
Ahead of a dry cold front, southwesterly winds will gradually
accelerate up to 20 mph as RH begins to decline. Notably, as the
cold front passes in the morning/early afternoon hours, a wind shift
from southwesterly to broadly westerly (perhaps to
west-northwesterly in the evening) is depicted by high-resolution
guidance, with sustained winds increasing up to 30 mph. Daytime RH
values will range from 5-15% within the risk area; though, should
increase to over 50% throughout overnight hours. The orientation of
enhanced 850-500 mb winds will gradually become more perpendicular
to the Cascades (and eventually the Northern Rockies in the late
afternoon) tightening surface pressure gradients, generating a
favorable environment for very strong downslope winds. In the lee
and immediate foothills of the higher terrain, sustained winds of
30+ mph are possible (gusts over 50 mph).
As the trough translates eastward in the afternoon, robust
southwesterly flow aloft will overspread the northern Rockies. High
resolution guidance depicts a 700 mb 60-70 kt emerging along the
Rocky Mountain front of north/central Montana, advancing strong
downslope sustained winds of up to 30 mph or greater (50+ mph gusts)
starting around 00z and persisting though the overnight hours. RH
values will range from 20-30 percent amid 99th annual percentile
ERCs and an increasingly receptive fuelscape. These overnight
meteorological conditions have led to an expansion in Critical fire
weather highlights, though locally extremely critical conditions may
be possible.
Elevated to locally critical fire weather conditions are likely
across the central mountains of Idaho into the Snake River Plain,
though recent rainfall across eastern Idaho preclude the expansion
of Critical highlights. Hot, dry and windy conditions on Day
2/Saturday will likely serve as a preconditioning-style event,
leading into expansive critical fire weather concerns on Day
3/Sunday alongside the emergence of lightning-induced holdovers.
See the previous discussion for more information.
..Elizalde-Garcia.. 07/31/2026
.PREV DISCUSSION... /ISSUED 0219 AM CDT Fri Jul 31 2026/
...Synopsis...
Upper-level ridging will remain in place from the Desert Southwest
into the northern High Plains on D2/Saturday as a potent upper-level
trough moves onshore across the Pacific Northwest and British
Columbia. As this occurs, a surface low will amplify across southern
Alberta, with a dry cold front progressing rapidly
east-southeastward through the Pacific Northwest and Northern
Rockies.
A tightening surface pressure gradient underlying a 35-45 kt 700 mb
jet will promote sustained strong southwesterly to westerly surface
winds amid a very dry boundary layer. The best overlap of these
conditions is forecast across portions of the Columbia Basin in
central and eastern Washington where dry, downslope flow in the lee
of the Cascades is expected to promote RH reductions to 15-20% in
conjunction with sustained surface winds of 20-30 mph (locally
higher in favored terrain/gap flow areas) and gusts of 35-45+ mph. A
few large wildfires are already ongoing across this region, and ERCs
are noted to be approaching or exceeding the 95th percentile. This
combination of meteorological and fuel conditions supports an
upgrade to Extremely Critical with this outlook issuance.
While the best overlap of the tightening surface pressure gradient
and strengthening mid-level winds is forecast across eastern
Washington, a broader area of critical fire weather conditions is
also expected from eastern Oregon and far western Idaho into eastern
Washington, the Idaho Panhandle, and northwestern/north-central
Montana. Across this region, sustained surface winds of 20-25 mph
are forecast to overlap very low RH of 5-20% (with the lowest RH
values forecast across southeastern Oregon and in the lee of the
Rockies in north-central Montana) and ERCs commonly above the 90th
to 98th percentiles. Recent guidance also suggests that a separate
area of stronger, pre-frontal southwesterly surface winds (up to 20
mph) may manifest across portions of eastern Idaho Saturday
afternoon, which may support locally critical fire weather concerns.
Sustained westerly/southwesterly winds of 15-20 mph, very low RH of
5-20%, and ERCs ranging from the 80th to 98th percentiles will also
foster Elevated fire weather concerns across a larger area
encompassing much of the northern Great Basin, eastern Pacific
Northwest, northern Rockies, and portions of the northern High
Plains.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 312150
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0450 PM CDT Fri Jul 31 2026
Valid 021200Z - 081200Z
...Synopsis...
Upper-level troughing should persist over the northeastern CONUS
into early next week, while high pressure will remain centered over
the Desert Southwest through the forecast period. An upper low will
transition into Saskatchewan on Day 3/Sunday with trailing amplified
southwesterly flow over the Northern Rockies and Montana plains.
Hot, dry, and windy conditions will promote widespread elevated to
critical fire weather concerns across much of the northwestern CONUS
on Day 3/Sunday, persisting into Day 4/Monday across portions of
western Wyoming and the northern Great Basin. Next week, long-range
guidance indicates mostly zonal flow will persist in the wake of the
upper trough, though some solutions indicate ridging may rebuild
across the western CONUS.
...Days 3-4/Sunday-Monday - Northwestern US...
As upper troughing shifts eastward on Day 3/Sunday, robust
southwesterly flow will overspread Idaho and Montana. Poor overnight
humidity recoveries will lead into Day 3/Sunday, permitting an
extended burning period and critical fire weather conditions to
return quickly across central Montana. Sustained westerly winds of
15-20 mph and 10-20% RH values will overlap very receptive fuels.
These meteorological conditions will also encompass eastern Idaho
and southwestern Montana, where lightning-induced holdovers may
emerge from thunderstorms earlier in the week. A southward
progressing dry cold front will enter the region on Day 3/Sunday
evening, resulting in a wind shift from broadly westerly to
northerly, which could impact any ongoing wildfires and containment
efforts across the area. While guidance is currently unclear in the
timing of this cold front, this feature will continue to be
monitored and discussed in future outlooks as confidence increases.
On Day 4/Monday, stronger southwest/westerly flow aloft will finally
begin to exit the region, pushing into the northern Plains and Upper
Midwest. Nevertheless, residual dry and breezy conditions are
expected across the northern Great Basin into western Wyoming and
far northwestern Colorado, supporting 40% Critical probabilities.
..Elizalde-Garcia.. 07/31/2026
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