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U.S. & Canada 12-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 260557
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Tue May 26 2026
Valid 261200Z - 271200Z
...Synopsis...
A robust upper level low will shift southward into the Great Basin
as a blocking ridge begins to establish over the central CONUS. Weak
upper troughing will also persist across the southern High Plains.
Meanwhile, a surface low will develop across the northern High
Plains as a cold front progresses eastward across the Great Basin.
Additional chances for wetting rainfall/thunderstorms are expected
across south-central Texas in association with a passing shortwave
trough and across much of the Southeast.
...Great Basin...
Southwesterly flow aloft and a deepening surface low will promote a
strengthening surface pressure gradient across the region. Ahead of
an eastward progressing cold front, sustained southwesterly surface
winds of 20-30 mph are expected and a deeply mixed and dry boundary
layer will support RH reductions of 15-20%. These conditions will
promote an elevated to locally critical fire weather threat amid
cured/drying fine fuels, primarily in lower elevation/mid-slope
areas. Only minor adjustments were made to the Elevated highlights
based on recent guidance.
...Northeastern Montana and Extreme Western North Dakota...
As the upper level trough in the Pacific Northwest progresses
southeastward towards the Great Basin, pronounced lee surface trough
development is expected across central MT. As a result,
southeasterly winds will accelerate to 15-20 mph across much of the
northern High Plains, while limited low-level moisture return will
support RH reductions to 15-20% during peak afternoon heating across
eastern MT. Delayed green up and existing dry fuels align with these
dry and breezy conditions, maintaining Elevated fire weather
highlights. Afternoon heating and resultant instability may support
isolated thunderstorm development along far southern and western MT.
Forecast soundings depict a prominent dry sub-cloud layer and PWATs
of 0.5-0.8", allowing some threat of dry thunderstorms to evolve.
However, sufficient green-up and less receptive fuels may otherwise
mitigate a broader IsoDryT threat.
..Elizalde-Garcia.. 05/26/2026
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 260558
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1258 AM CDT Tue May 26 2026
Valid 271200Z - 281200Z
A nearly stationary upper level low will hover over the CA/Great
Basin region through Day 2/Wednesday as an upper ridge will continue
to reside across the central CONUS. Strengthening southerly flow
aloft and tightening surface pressure gradients east of a persisting
surface low will promote a fire weather threat for portions of the
Southwest and Upper Colorado River Basin. Farther east, a weak
shortwave is expected to eject across the central and southern
Plains, bringing additional chances of appreciable precipitation to
a drought-stressed landscape.
...Eastern Great Basin and Southwest...
Broad southwesterly flow associated with the hovering upper low will
sustain fire weather concerns for portions of the eastern Great
Basin and Southwest. Southerly surface winds of 15-20 mph and RH
reductions of 10-20% will promote Elevated to locally critical fire
weather conditions amid available dry fuels.
...Northeastern Montana...
Prolonged lee surface troughing and increasing mid level flow should
support gusty surface winds across eastern MT. However, recent
guidance portrays increasing low-mid level moisture as flow
transitions southeasterly. Modest surface RH of 30-40% may alleviate
broader fire weather concerns, though elevated conditions may arise
if moisture does not advect as far north as guidance depicts. Trends
will be monitored for future outlook cycles.
..Elizalde-Garcia.. 05/26/2026
.PREV DISCUSSION... /ISSUED 0226 AM CDT Mon May 25 2026/
...Synopsis...
A robust upper-level trough will shift southward into the Great
Basin on D2/Tuesday as a blocking ridge begins to establish over the
central CONUS. Weak upper troughing will also persist across the
southern High/Great Plains. Meanwhile, a surface low will develop
across the northern High Plains as a cold front progresses eastward
across the Great Basin. Additional chances for wetting
rainfall/thunderstorms are expected across the southern High Plains
in association with a passing shortwave trough and across much of
the Southeast.
...Northeastern Montana...
Increasing southeasterly flow ahead of an evolving lee
trough/strengthening surface low is expected across much of the
northern High Plains on D2/Tuesday, with sustained surface winds of
around 15-25 mph and occasional wind gusts up to 30 mph expected.
Greater low-level moisture is forecast to remain displaced to the
east across the Dakotas, with forecast guidance/soundings depicting
deep, well-mixed boundary layer profiles and RH reductions to near
15% across much of eastern/northeastern Montana. With dry fuels
across much of northeastern Montana, these conditions are expected
to support elevated to locally critical fire weather concerns
Tuesday afternoon. Consideration was given to a westward expansion
of elevated highlights; however, uncertainty regarding the
coverage/development of high-based convection in association with a
northward shifting mid-level shortwave trough also increases with
westward extent. Trends will be monitored for future outlook cycles.
...Great Basin...
As the aforementioned upper-level trough shifts southward into the
Great Basin on Tuesday, a deepening surface low will promote a
strengthening surface pressure gradient ahead of the eastward
progressing cold front. Sustained southwesterly surface winds of
20-30 mph are expected amid this strengthening gradient, with
well-mixed boundary layer profiles supporting RH reductions to
15-20% (locally lower). Accelerating mid-level flow may also support
occasional wind gusts to 30-35 mph (perhaps higher in exposed,
elevated terrain areas). With near critically dry fuels across the
region, these conditions are expected to support a broad area of
elevated fire weather concerns, with locally critical conditions
possible in areas of drier fine fuels.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 252120
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0420 PM CDT Mon May 25 2026
Valid 271200Z - 021200Z
...Synopsis...
An upper-level low meanders around the CA/Great Basin region
through midweek. Deep-layer and dry, southwesterly flow southeast of
the upper low will continue to promote a fire weather threat for
portions of the Southwest and Upper CO River Basin Days
3-4/Wednesday-Thursday. The upper low evolves into an open trough by
Day 5/Friday before rushing northward into southern Canada over the
weekend, allowing drier conditions to return to the West Coast
states after several preceding days of precipitation and cooler
temperatures. A blocking ridge should remain anchored over the
central CONUS into Canada through early June.
...Day 3-4/Wednesday-Thursday...
...Eastern Great Basin and Southwest...
Broad southwesterly flow associated with the slow moving upper low
should sustain fire weather concerns for portions of the eastern
Great Basin and Southwest Days 3-4/Wednesday-Thursday. In general,
sustained southwest winds of 15-20 mph (25 mph in favorable terrain)
amid surface RH in the 10-20% range will support elevated to
critical fire weather conditions amid available dry fuels. The
waning of stronger mid-level winds and resultant dissolving surface
pressure gradients should bring some reprieve to the region as early
as Friday as the mid/upper wave begins to translate northward.
...Days 5-8/Friday-Tuesday...
Longer term forecast guidance continues to show a reduced fire
weather threat across the western U.S., primarily due to a lighter
wind regime associated with the blocking ridge. However, drier and
warmer conditions returning after the upper trough exodus will
support drying/curing of fuels across much of the region over the
weekend into early next week.
..Williams.. 05/25/2026
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