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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 211609
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1109 AM CDT Fri Aug 21 2026
Valid 211700Z - 221200Z
Both the Elevated wind/RH area and the Isolated Dry Thunderstorm
area were adjusted slightly based on the latest forecast guidance
and morning observations. Given overcast to broken cloud cover
streaming in across much of western/central OR and WA this morning
and forecast guidance continuing to suggest that it will build
throughout the day, the far southern extent of the Isolated Dry
Thunderstorm area was trimmed northward. If breaks in the clouds do
develop, there will be opportunity for a mostly dry thunderstorm or
two, particularly across OR this afternoon. The remaining
highlighted area shows the best opportunity for nocturnal convection
along and near the Cascade Crest and Olympic Peninsula, as
previously mentioned, being primarily after 06Z tonight into
tomorrow (Saturday) morning. Additionally, given the tightening
pressure gradient in place further east across the low elevations of
southwest ID, the Elevated wind/RH area was expanded slightly
eastward to include more of southern ID where fuels remain very dry.
..Stearns.. 08/21/2026
.PREV DISCUSSION... /ISSUED 0158 AM CDT Fri Aug 21 2026/
...Synopsis...
Along the northwestern periphery of an expansive upper ridge over
the West, a midlevel low will track slowly northeastward off the
Pacific Northwest coast. Accompanying this feature, a belt of
enhanced deep-layer south-southwesterly flow will overspread parts
of the central and northern Great Basin. Deep boundary-layer mixing
amid this enhanced flow aloft will yield 15-20 percent RH and around
15 mph sustained south-southwesterly surface winds across parts of
northeast CA, northwest NV, and southern OR. These dry/breezy
conditions atop dry fuels will result in elevated fire-weather
conditions during the afternoon.
Farther north, midlevel height falls/forcing for ascent preceding
the midlevel low will gradually overspread parts of the Pacific
Northwest late in the forecast period (generally after 06Z). Ample
midlevel moisture and steepening midlevel lapse rates will
contribute to sufficient instability for isolated thunderstorm
development during this time frame, and given receptive fuels,
lightning-induced ignitions will be a concern. Isolated high-based
thunderstorms will also be possible along the Cascades in OR during
the afternoon, though limited large-scale forcing for ascent casts
uncertainty on overall storm coverage compared to areas farther
north late in the period.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 211959
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0259 PM CDT Fri Aug 21 2026
Valid 221200Z - 231200Z
...CRITICAL FIRE WEATHER AREA FOR MUCH OF NORTHERN WASHINGTON AND
THE FAR NORTHERN IDAHO PANHANDLE...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF
SOUTH-CENTRAL/SOUTHEAST WASHINGTON AND FAR NORTH-CENTRAL OREGON...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHEAST
CALIFORNIA...NORTHWEST NEVADA...AND SOUTH-CENTRAL/SOUTHEAST
OREGON...
An area of Scattered Dry Thunderstorms was added to much of northern
WA state and the far northern ID Panhandle. This area will
experience greater coverage of dry thunderstorms amid high-based,
fast moving, and drier air aloft behind the frontal passage later in
the day as the trough continues a slow eastward progression. While
more northwestern extents of the Scattered Dry Thunderstorm area are
expected to accumulate higher rainfall amounts, it will be amid some
of the driest and heaviest fuel loading.
An area of Critical Wind/RH was also introduced over central
portions of the Columbia River Basin. Ahead of the cold front
passage, sustained southwesterly winds of 15-25 mph amid afternoon
RHs of 15-25% within this area. Winds will turn west-northwesterly
as the front passes through central WA and OR in the late
afternoon/early evening time frame. The existing Critical Wind/RH
area along with the larger Elevated and Isolated Dry Thunderstorm
area remain on track.
..Stearns.. 08/21/2026
.PREV DISCUSSION... /ISSUED 0201 AM CDT Fri Aug 21 2026/
...Synopsis...
A robust midlevel trough and accompanying south-southwesterly jet
max will overspread the Northwest through the period -- along the
northwestern periphery of an upper ridge centered on the Rockies. In
the low-levels, a cold front will move eastward across parts of WA
and OR during the day.
...Northern/Central Intermountain West...
Beneath the midlevel jet streak, enhanced deep-layer
south-southwesterly flow will overspread a dry antecedent air mass
across parts of the northern and central Intermountain West. This
will result in a broad area of 15-20 mph sustained
west-southwesterly surface winds and 15-20 percent RH during the
afternoon. Given receptive fuels across the region, elevated
fire-weather conditions are expected. Over parts of northeast CA,
northwest NV, and south-central/southeast OR, the overlap of 20-25
mph sustained southwesterly surface winds and around 15 percent RH
will favor critical fire-weather conditions. Locally critical
conditions will also be possible within the Cascade gaps, though
these conditions appear too localized for an additional Critical
area at this time.
...Dry Thunderstorms...
Robust midlevel height falls/forcing for ascent accompanying the
midlevel trough will overspread the northern Intermountain West into
the northern Rockies during the day. Here, deep boundary-layer
mixing beneath a midlevel moisture plume will yield sufficient
buoyancy for isolated to widely scattered high-based thunderstorms
regionally. While 0.7-1 inch PW will support a mix of wet and dry
storms, quick storm motions and the deep/dry boundary layer should
tend to limit overall rainfall. Therefore, isolated
lightning-induced ignitions will be possible atop increasingly
dry/receptive fuels. Additionally, the stronger storms will be
capable of producing strong to severe outflow winds (especially
toward the northern Rockies). For details on the severe risk, see
the SPC Day 2 Convective Outlook.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 212148
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0448 PM CDT Fri Aug 21 2026
Valid 231200Z - 291200Z
...Synopsis...
The current trough driving the fire weather threat on Days 1-2
continues to move northeastward on Day 3/Sunday. High pressure
remains in place over much of the south-central portions of the
CONUS with shortwave trough passages periodically moving across the
crest of the ridge through the northern states. As we turn the
corner toward next week, the ridge amplifies slightly and builds
over the Intermountain West once again. By mid-to-late next week,
another impactful trough will again approach the western CONUS.
While differences in timing remain, making the threat uncertain for
any particular day, highlights are likely across the Pacific
Northwest once again as the system approaches shore. This will be
monitored with future forecast guidance.
...Northern Rockies/Northern High Plains...
Northwesterly winds over portions of the northern High Plains and
nearby northern Rocky Mountains remain a concern on Day 3/Sunday.
Across much of central MT, sustained westerly winds of 10-20 mph
will occur amid afternoon RHs of 15-25%. The existing 40% Critical
Wind/RH probabilities were adjusted slightly westward on Day
3/Sunday and also reach into the central higher elevations of ID.
Additionally, a 10% risk of Dry Thunderstorms was introduced over
much of the same area, which is of particular concern. While fuels
are not quite as dry as in portions of the Pacific Northwest
anticipated to receive Dry Thunderstorm activity in the preceding 36
hours, very strong thunderstorm outflows (see the SPC Convective
Outlook for this time frame) amid warm, dry, and windy surface
conditions will present simultaneous concerns for new ignitions and
fire spread potential. This area will be monitored closely for
possible critical wind/RH and increasing thunderstorm coverage.
...Pacific Northwest...
Lingering moisture, quick-moving storms, and dry fuels (ERCs near
the 80-95th percentile) remain in place on Day 3/Sunday as mostly
dry thunderstorms are expected to initiate for another afternoon
along the international border with WA. The existing 10% Dry
Thunderstorm risk area was maintained over far northeastern WA. On
Day 4/Monday, a 10% risk area is highlighted over southwest ID,
southeast OR, and portions of northern NV as monsoonal moisture
aloft continues to meander further north/west over drier fuels.
...Southern Plains...
On Day 3/Sunday and Day 4/Monday, a front and tightened surface
pressure gradient over the southern Plains will increase fire
weather risk. Current ensemble forecast guidance suggests sustained
10-20 mph south to southwesterly winds will combine with afternoon
RHs near 15-20% across the TX/OK Panhandles and surrounding areas
with critically dry fuels.
..Stearns.. 08/21/2026
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