|
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 251652
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1152 AM CDT Sat Jul 25 2026
Valid 251700Z - 261200Z
...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS
CENTRAL/SOUTHERN MONTANA...
...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE PACIFIC NORTHWEST INTO
THE NORTHERN ROCKIES...
Meteorological conditions amid numerous wildfires and 90-95th
percentile ERCs across the northwestern U.S. will lead to another
day of expansive, and potentially dangerous, fire concerns.
A Scattered Dry Thunderstorm risk was introduced across
central/southern Montana where a greater coverage of thunderstorms
and lightning ignitions are possible atop receptive fuels. Forecast
soundings depict a hot and well-mixed environment this afternoon
with deep inverted-V profiles, ample MUCAPE, and 25-35 kt LCL-EL
winds, indicating thunderstorms will be capable of severe
wind-potential and less precipitation efficiency (See the Day 1
Convective outlook). The Isolated Dry Thunderstorm risk area was
expanded into northwestern South Dakota and northeastern Wyoming
based on the latest observations and forecast guidance. Lightning
ignitions are also possible outside of the Isolated Dry Thunderstorm
highlights, on the periphery of heavier precipitation cores where
fuels are receptive.
Despite moderate RH recoveries across portions of the Pacific
Northwest, values are quickly declining and will approach critical
thresholds (15% or less) by peak heating. Southwesterly to westerly
sustained surface winds are expected to exceed 20 mph, perhaps
approaching 25 mph in terrain-favored areas. Locally extremely
critical conditions may be possible where these stronger sustained
winds overlap critically low RH, in addition to wind gusts of 30-40
mph particularly in the Columbia Basin and western/central Montana.
These conditions will further exacerbate the fire environment,
impacting any new/ongoing wildfires and control efforts.
..Elizalde-Garcia.. 07/25/2026
.PREV DISCUSSION... /ISSUED 1143 PM CDT Fri Jul 24 2026/
...Synopsis...
Upper ridging will prevail over the western and central CONUS today.
A belt of stronger mid-level flow, accompanied by embedded mid-level
impulses, will traverse the periphery of the upper ridge and
overspread the West Coast toward the northern Rockies. This belt of
stronger flow aloft will support dry and windy conditions supportive
of wildfire spread, with deep-layer ascent associated with embedded
impulses also supporting dry thunderstorm initiation, especially
over portions of Montana.
...Parts of the northern Sierra to the northern Rockies...
Through the afternoon, a dry boundary layer will mix upward to the
mid-levels, allowing for downward momentum transport of the
aforementioned stronger mid-level flow aloft. By afternoon peak
heating, sustained southwesterly surface winds exceeding 20 mph
should become widespread, especially in terrain favoring areas, from
the northern Sierra to the northern Rockies. Fifteen percent RH
should be common by afternoon peak heating, overlapping with many
areas experiencing 20+ mph sustained winds, warranting widespread
Critical highlights given dry fuels.
...Portions of Montana...
Guidance consensus (including high-resolution members) depicts at
least scattered thunderstorm development across much of Montana by
afternoon as a mid-level impulse overspreads the region. Forecast
soundings show classic inverted-v profiles extending up to 500 mb,
amid appreciable flow aloft. As such, fast-moving and high-based
storms will promote dry lightning strikes over fuel beds receptive
to fire spread, warranting isolated dry thunderstorm highlights.
Furthermore, strong vertical wind shear will accompany the mid-level
impulse, and given appreciable buoyancy aloft, several of these
storms may produce strong to severe wind gusts, which may exacerbate
any ongoing fires or holdovers. Please see the latest Day 1
Convective outlook for more details on the severe thunderstorm
threat.
|
U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 251921
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0221 PM CDT Sat Jul 25 2026
Valid 261200Z - 271200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN MONTANA...
...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE NORTHERN SIERRA INTO
SOUTHEASTERN OREGON...
Minimal changes were made to the outlook areas based on recent
guidance. Isolated dry thunderstorms are possible across far
southern Montana and northern Wyoming on Day 2/Sunday; however, the
broader region is expected benefit from rainfall on Day 1/Saturday
and ERCs are forecast to range from the 70-80th percentile,
precluding highlights. Nevertheless, lightning ignitions cannot be
ruled out where pockets of dry fuels exist. See the previous
discussion for more information.
..Elizalde-Garcia.. 07/25/2026
.PREV DISCUSSION... /ISSUED 1156 PM CDT Fri Jul 24 2026/
...Synopsis...
An upper ridge will remain in place across the western and central
CONUS tomorrow (Sunday). A belt of stronger mid-level flow will
overspread the northern Sierra and pivot clockwise around the upper
ridge to the northern High Plains, supporting dry and gusty
conditions near the surface. As this flow is mixed downward to the
surface by a deep and dry boundary layer during the afternoon areas,
widespread 15+ mph sustained southwesterly surface winds will be
common. Given RH dipping to at least 20 percent, widespread Elevated
highlights have been introduced, from the Pacific Northwest to the
northern Rockies and northern High Plains. Additionally, guidance
consensus continues to indicate locally stronger surface wind
fields, atop dry fuels, over portions of northern Montana and the
northern Sierra to Harney Basin. Over both of these areas, 15
percent RH will coincide with the stronger winds for several hours,
warranting Critical highlights.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 242143
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0443 PM CDT Fri Jul 24 2026
Valid 261200Z - 011200Z
Upper-level troughing will continue to impinge of the Pacific
Northwest with the main upper low/trough likely remaining offshore.
However, mid-level shortwave troughs will occasionally rotate
through the southwest flow aloft. An upper high will be over the
southern High Plains/vicinity before slowly shifting back to the
west with upper-level ridging likely to build over much of the West
late in the outlook period. Daily monsoonal thunderstorms remain
likely across the Four Corners region, but a slight drying trend is
possible.
...Northwestern US...
Dry and breezy conditions will continue across much of the
northwestern US on Day 3/Sunday as upper-level troughing spreads
farther inland across the region. Elevated to locally critical
conditions are expected, with portions of northern Montana and from
the Sierra Front northward into southeast Oregon favored for
critical conditions. If deeper boundary layer mixing can occur
across more of the Inland Northwest and northern Rockies, critical
winds/RH become more likely due to the stronger winds between
700-500 mb.
Hot, dry, and breezy conditions will develop across large swaths of
the northern Plains on Day 3/Sunday. Isolated to scattered
thunderstorms are likely across portions of southern Montana,
northern/eastern Wyoming into western South Dakota. Drier
thunderstorms are possible within this corridor, but there is enough
uncertainty regarding the coverage, rainfall amounts, and the
following days' thunderstorm/rain chances to preclude issuing
IsoDryT probabilities at this time.
Lingering dry and breezy conditions are expected on Day 4/Monday
across portions of northwestern US. If stronger flow aloft remains
over enough of this region and deeper mixing becomes more likely
across a broader area, an expansion of 40% probabilities will be
warranted. The forecast uncertainty regarding the interplay of the
upper-level troughing in the Pacific Northwest/vicinity and the
upper-level ridge over the Plains and much of the Intermountain West
has precluded more/higher probabilities of critical conditions on
Day 4/Monday - Day 6/Wednesday.
...Southern High Plains...
Hot, dry, and breezy conditions are likely to develop across
portions of the southern High Plains late this weekend through at
least mid-week. A 40% area was maintained on Day 4/Monday but
adjusted due to uncertainty regarding live fuel moisture in this
region. Day 4/Monday may be too soon for probabilities, especially
if winds remain below 20 mph. This area will be monitored going
forward.
..Nauslar.. 07/24/2026
|
