WW 628 SEVERE TSTM AR OK TX 262010Z - 270300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 628
NWS Storm Prediction Center Norman OK
310 PM CDT Wed Aug 26 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Arkansas
Eastern and Southeastern Oklahoma
Far Northeast Texas
* Effective this Wednesday afternoon and evening from 310 PM
until 1000 PM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Thunderstorms are ongoing from parts of northern and
central Arkansas into far east-central Oklahoma. Thunderstorm
coverage is expected to increase in these areas this afternoon and
evening, as well as farther south in the Arklatex vicinity. Strong
to severe thunderstorms are possible, with damaging wind gusts as
the primary severe risk. Some isolated large hail is possible as
well.
The severe thunderstorm watch area is approximately along and 75
statute miles east and west of a line from 15 miles northeast of
Flippin AR to 30 miles south of Texarkana AR. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
36020.
...Mosier
WW 0628 Status Updates
STATUS FOR WATCH 0628 HAS NOT BEEN ISSUED YET
MD 2139 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEAST WYOMING...FAR SOUTHWEST NEBRASKA PANHANDLE...AND EASTERN COLORADO
Mesoscale Discussion 2139
NWS Storm Prediction Center Norman OK
0243 PM CDT Wed Aug 26 2026
Areas affected...southeast Wyoming...far southwest Nebraska
Panhandle...and eastern Colorado
Concerning...Severe potential...Watch possible
Valid 261943Z - 262215Z
Probability of Watch Issuance...60 percent
SUMMARY...An initially isolated severe storm threat is expected to
develop by mid to late afternoon, mainly in the form of large hail
up to two inches. The potential for severe wind gusts up to 65-75
mph may increase this evening. A watch is possible by 21-22Z.
DISCUSSION...Visible satellite and lightning data indicate deepening
cumulus and early thunderstorm development from the Laramie
Mountains to the Sangre de Cristo Range, as well as along a subtle
boundary over east-central CO into northwest KS. The presence of
steep low/mid-level lapse rates, surface dewpoints in the 50 to low
60s, and considerable daytime heating are contributing to a
destabilizing air mass east of the mountains with MLCAPE expected to
increase to 1500-2000 J/kg later this afternoon with minimal
convective inhibition. As such, expect storms to gradually move off
the high terrain with greater uncertainty in the evolving convection
over east-central CO. The presence of 30-35 kt of deep-layer shear
may support a few supercells capable of large hail up to two inches
as the initial hazard.
By this evening, there is some model signal for storms to merge into
clusters, at which point the threat for severe winds with gusts up
to 65-75 mph would increase.
..Mead/Mosier.. 08/26/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GLD...PUB...BOU...CYS...
LAT...LON 38720513 40010526 40930528 41600496 41670414 40820286
40100228 38980213 37880233 37310327 37230400 37460474
38720513
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1127 AM CDT Wed Aug 26 2026
Valid 261630Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN GREAT LAKES/MIDWEST...CENTRAL HIGH PLAINS...AND
OZARKS/MID-SOUTH INTO THE LOWER MISSISSIPPI VALLEY...
...SUMMARY...
Isolated to widely scattered severe thunderstorms are forecast today
across parts of the southern Great Lakes into the Midwest,
central/southern High Plains, and the Ozarks into the Mid-South and
Lower Mississippi Valley. Severe/damaging winds should be the main
threat across these regions, though large hail is also possible,
particularly across the central High Plains.
...Mid-South/TN Valley...
An MCS continues to push gradually southward/southeastward across
western and middle TN. The downstream airmass is heating and
destabilizing, but vertical shear remains weak and the overall
system has not strengthened notably in the past hour.
Destabilization across the region is strongest from the Mid-South
into the Lower MS Valley, where dewpoints are largely in the mid
70s. Less low-level moisture is noted from middle TN into northern
AL, but airmass destabilization is still anticipated amid modest
heating. The general expectation is for the MCS to continue, but
with new and/or stronger updrafts likely trending towards the
western flank where the buoyancy is greatest. Even then, the lack of
stronger vertical shear suggests an outflow-dominant mode with
minimal organization. As such, sporadic damaging gusts are possible,
particularly via updraft augmentation via storm interactions, but
the current magnitude and orientation of the wind probability seems
sufficient.
...Arklatex across much of AR into the Mid-South/Lower MS Valley...
A somewhat separate area of thunderstorm development is anticipated
this afternoon west of what was discussed in the previous paragraph,
although some interaction between these two regimes may occur over
the Mid-South vicinity. Recent surface observations depict a surface
low along the central TX/OK border (in the GYI/DUA vicinity). This
low is forecast to progress gradually eastward into a moist and
diurnally destabilized airmass from the Arklatex across much of AR
and northern LA. A weak MCV, noted in visible satellite imagery,
lags behind this surface low, and could augment ascent as it too
moves eastward. Low-level convergence on a stalled frontal boundary
that extends across central AR as well as along a front approaching
northern AR this evening could act as additional mechanisms for
thunderstorm initiation. All of these factors will likely result in
scattered to numerous thunderstorms across the region.
Modest deep-layer shear should support some updraft organization,
with multicell clusters likely the dominant mode. High total
precipitable water values and large buoyancy will support robust
downbursts capable of damaging wind gusts. Strong buoyancy could
support occasional hail as well. Clustering may eventually result in
several bowing segments this evening. As such, there is potential
for at least isolated damaging winds to persist across parts of
southern LA/MS.
...Southern Great Lakes into the Midwest...
Satellite imagery continues to show a well-defined shortwave trough
moving across the Upper Great Lakes. Primary surface low associated
with this system is occluded over northwest Ontario, but a secondary
triple point low is moving across Upper MI. This system is forecast
to move eastward today, with the attendant cold front progressing
southeastward. Modest low-level moisture advection and heating ahead
of this front will result in a corridor of moderate to strong
buoyancy from central IL northeastward into southern Lower MI.
Thunderstorm development is anticipated within this corridor this
afternoon.
Low/mid-level winds will tend to remain fairly modest and veered,
but 25-35 kt of deep-layer shear should foster some updraft
organization. A mix of multicell clusters and marginal supercells
should pose a threat for both hail and damaging winds, with the wind
threat potentially becoming the primary risk with eastward extent
into the Midwest as thunderstorms grow upscale. Veered low-level
flow should keep the tornado potential low. The overall severe
threat will likely diminish quickly this evening as convection
outpaces the low-level moisture/instability, and nocturnal cooling
stabilizes the boundary layer.
...Central High Plains...
Low levels across the central High Plains are currently
characterized by dewpoints in the upper 50s and low 60s. Modest
low-level upslope flow will help maintain this low-level moisture
through the afternoon. This moisture combined with diurnal heating
and steep mid-level lapse rates will result in airmass
destabilization and moderate buoyancy by the late afternoon.
Additionally, southern periphery of the enhanced northwesterly flow
extending from the northern Plains into the Mid MS Valley will be
over the central High Plains, resulting in 25 to 35 kt of effective
bulk shear. Late afternoon thunderstorm development is anticipated
within this environment, with some isolated supercells possible.
Hail will be the primary risk initially, particularly across the CO
Foothills. A trend towards clustering and more damaging wind
potential is expected as this activity spreads east-southeastward
through the evening.
...Southern High Plains...
Mid-level flow and related deep-layer shear should be somewhat
weaker than areas farther north. Still, convection that develops
across central into eastern NM may become loosely organized while
posing an isolated threat for severe gusts given the presence of a
very well-mixed boundary layer. This threat may continue into parts
of the OK/TX Panhandles and west TX through the evening before
eventually weakening.
..Mosier/Chalmers.. 08/26/2026
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0259 PM CDT Wed Aug 26 2026
Valid 262000Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN GREAT LAKES/MIDWEST...CENTRAL HIGH PLAINS...AND
OZARKS/MID SOUTH INTO THE LOWER MISSISSIPPI VALLEY...
...SUMMARY...
Isolated to widely scattered severe thunderstorms are forecast today
across parts of the southern Great Lakes into the Midwest,
central/southern High Plains, and the Ozarks into the Mid-South and
Lower Mississippi Valley. Severe/damaging winds should be the main
threat across these regions, though large hail is also possible,
particularly across the central High Plains.
...20z Update...
...Central Great Plains...
Visible satellite imagery depicts an area of agitated cumulus
developing in close proximity to a weak surface boundary across
eastern Colorado. Recent HRRR/RRFS runs are split on the evolution
of this convection, with the HRRR suggesting minimal thunderstorm
development and the RRFS depicting the development of a
southeastward-propagating cluster. This scenario remains uncertain;
however, the 5% wind probabilities have been expanded southeastward
to account for the potential for a cluster of thunderstorms to
evolve from this region. See MCD 2139 for additional short-term
information.
...Mid-South and Lower Great Lakes...
Severe probabilities were trimmed slightly across portions of
northeastern IL, northwestern IN, and southwestern MI in the wake of
ongoing convection and the passage of a surface cold front. Severe
probabilities were also trimmed across portions of the Mid South
where increased low-level static stability owing to outflow from
prior convection casts uncertainty on additional convective
development this afternoon/evening.
Elsewhere, the forecast remains largely on track with only minor
changes made to the existing outlook. See the text below for
additional information.
..Chalmers/Thornton.. 08/26/2026
.PREV DISCUSSION... /ISSUED 1127 AM CDT Wed Aug 26 2026/
...Mid-South/TN Valley...
An MCS continues to push gradually southward/southeastward across
western and middle TN. The downstream airmass is heating and
destabilizing, but vertical shear remains weak and the overall
system has not strengthened notably in the past hour.
Destabilization across the region is strongest from the Mid-South
into the Lower MS Valley, where dewpoints are largely in the mid
70s. Less low-level moisture is noted from middle TN into northern
AL, but airmass destabilization is still anticipated amid modest
heating. The general expectation is for the MCS to continue, but
with new and/or stronger updrafts likely trending towards the
western flank where the buoyancy is greatest. Even then, the lack of
stronger vertical shear suggests an outflow-dominant mode with
minimal organization. As such, sporadic damaging gusts are possible,
particularly via updraft augmentation via storm interactions, but
the current magnitude and orientation of the wind probability seems
sufficient.
...Arklatex across much of AR into the Mid-South/Lower MS Valley...
A somewhat separate area of thunderstorm development is anticipated
this afternoon west of what was discussed in the previous paragraph,
although some interaction between these two regimes may occur over
the Mid-South vicinity. Recent surface observations depict a surface
low along the central TX/OK border (in the GYI/DUA vicinity). This
low is forecast to progress gradually eastward into a moist and
diurnally destabilized airmass from the Arklatex across much of AR
and northern LA. A weak MCV, noted in visible satellite imagery,
lags behind this surface low, and could augment ascent as it too
moves eastward. Low-level convergence on a stalled frontal boundary
that extends across central AR as well as along a front approaching
northern AR this evening could act as additional mechanisms for
thunderstorm initiation. All of these factors will likely result in
scattered to numerous thunderstorms across the region.
Modest deep-layer shear should support some updraft organization,
with multicell clusters likely the dominant mode. High total
precipitable water values and large buoyancy will support robust
downbursts capable of damaging wind gusts. Strong buoyancy could
support occasional hail as well. Clustering may eventually result in
several bowing segments this evening. As such, there is potential
for at least isolated damaging winds to persist across parts of
southern LA/MS.
...Southern Great Lakes into the Midwest...
Satellite imagery continues to show a well-defined shortwave trough
moving across the Upper Great Lakes. Primary surface low associated
with this system is occluded over northwest Ontario, but a secondary
triple point low is moving across Upper MI. This system is forecast
to move eastward today, with the attendant cold front progressing
southeastward. Modest low-level moisture advection and heating ahead
of this front will result in a corridor of moderate to strong
buoyancy from central IL northeastward into southern Lower MI.
Thunderstorm development is anticipated within this corridor this
afternoon.
Low/mid-level winds will tend to remain fairly modest and veered,
but 25-35 kt of deep-layer shear should foster some updraft
organization. A mix of multicell clusters and marginal supercells
should pose a threat for both hail and damaging winds, with the wind
threat potentially becoming the primary risk with eastward extent
into the Midwest as thunderstorms grow upscale. Veered low-level
flow should keep the tornado potential low. The overall severe
threat will likely diminish quickly this evening as convection
outpaces the low-level moisture/instability, and nocturnal cooling
stabilizes the boundary layer.
...Central High Plains...
Low levels across the central High Plains are currently
characterized by dewpoints in the upper 50s and low 60s. Modest
low-level upslope flow will help maintain this low-level moisture
through the afternoon. This moisture combined with diurnal heating
and steep mid-level lapse rates will result in airmass
destabilization and moderate buoyancy by the late afternoon.
Additionally, southern periphery of the enhanced northwesterly flow
extending from the northern Plains into the Mid MS Valley will be
over the central High Plains, resulting in 25 to 35 kt of effective
bulk shear. Late afternoon thunderstorm development is anticipated
within this environment, with some isolated supercells possible.
Hail will be the primary risk initially, particularly across the CO
Foothills. A trend towards clustering and more damaging wind
potential is expected as this activity spreads east-southeastward
through the evening.
...Southern High Plains...
Mid-level flow and related deep-layer shear should be somewhat
weaker than areas farther north. Still, convection that develops
across central into eastern NM may become loosely organized while
posing an isolated threat for severe gusts given the presence of a
very well-mixed boundary layer. This threat may continue into parts
of the OK/TX Panhandles and west TX through the evening before
eventually weakening.
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1213 PM CDT Wed Aug 26 2026
Valid 271200Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID-ATLANTIC AND NORTHEAST...
...SUMMARY...
Scattered strong to severe thunderstorms are possible across parts
of the Northeast on Thursday. Damaging wind, hail and a tornado or
two may accompany these storms. Strong wind gusts and hail also may
occur over parts of the central Plains, and the Northern Rockies
vicinity.
...Mid-Atlantic/Northeast...
Upper troughing will persist over the eastern U.S., with the trough
axis remaining roughly oriented from the Lower Great Lakes toward
the central/southern Appalachians. This will result in modest
southwesterly deep-layer flow across region, with somewhat strong
vertical wind profiles expected across the Northeast (and decreasing
with southward extent across central/southern Appalachians). A
surface trough/weak front will extend from the Upper OH Valley
southward toward northern GA Thursday morning, with this feature
drifting eastward through early Friday. Southerly low-level flow
east of the surface trough/boundary, will maintain a seasonally
moist boundary layer (60s F dewpoints). This will support moderate
destabilization across the region, with pockets of strong
instability possible near/west of the I-95 corridor from northern VA
into southern/central NY.
Vertically veering wind profiles are evident in forecast soundings,
with around 25-35 kt effective shear magnitudes suggesting organized
storms structures and possible transient supercells. Damaging winds
and occasional hail will be the main hazards with storms through
Thursday evening. Low-level hodographs are somewhat small, but
favorably curved, with 0-1 km SRH approaching 100 m2/s2 where backed
low-level winds persist. Given the moist boundary layer and
sufficient steep low-level lapse rates, a tornado or two also will
be possible.
Vertical shear decreases with southward extent across the
Appalachians. However, high PW and sufficient instability will exist
that thunderstorm clusters could produce wet microbursts and
sporadic wind damage of marginal hail as far south as northeast
TN/northwest NC.
...Central Plains...
Northwesterly flow aloft will persist over the region on Thursday as
the western upper ridging begins to shift east over the High Plains.
This will likely suppress convective coverage somewhat. However,
modest vorticity maxima rotating through northwesterly flow aloft
and stronger heating across the modestly moist airmass, along with
possible outflow from prior convection will support isolated
thunderstorm development from the Black Hills southeast into
Nebraska. Elongated hodographs and effective shear around 35+ kt
amid steep midlevel lapse rates suggest large hail will be possible,
with some potential for hail greater than 2 inch diameter. Overall
storm coverage is expected to remain low, precluding higher severe
probabilities.
Additional thunderstorms are possible with upslope flow along the CO
foothills vicinity. Weaker vertical shear is expected compared to
further north, but the environment will still support marginal hail
with stronger updrafts.
...Northern Rockies...
Southwesterly flow aloft will increase as an upper shortwave trough
moves eastward from the Pacific Northwest into MT and Alberta. Steep
midlevel lapse rates will support modest destabilization by early
afternoon and isolated to scattered thunderstorms are expected to
develop over higher terrain. Strong heating will result in deep
boundary layer mixing and steep low-level lapse rates. Given
stronger flow aloft, isolated strong to severe wind gusts will be
possible as convection develops east/northeast through early
evening.
..Leitman.. 08/26/2026
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0207 PM CDT Wed Aug 26 2026
Valid 281200Z - 291200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN AND CENTRAL PLAINS...AND FROM NORTH GA INTO SOUTHEAST
VA...
...SUMMARY...
Isolated strong to severe storms are possible across northern
Georgia into the Carolinas and the northern/central Plains.
...Northern/Central Plains...
An upper ridge, centered from the southern Rockies to the western
Dakotas will persist on Friday. Some enhancement to
west/northwesterly flow aloft is forecast, and a surface trough will
develop across the northern and central High Plains. Southerly
low-level flow to the east of the surface trough will transport 60s
F dewpoints northward from the central into the northern Plains. As
a low-level jet strengthens during the evening, thunderstorm
development is possible. Capping may limit surface-based convection.
However, forecast soundings indicate supercell wind profiles amid
moderate instability and steep midlevel lapse rates. If storms
develop, large hail will be possible.
...North GA into southeast VA...
Upper troughing will persist across the eastern U.S. on Friday.
Surface high pressure will build over the Midwest while a surface
trough extends from the southern Mid-Atlantic into the southern
Appalachians. East of the trough, a very moist airmass will be in
place. Daytime heating of this very moist/high PW airmass will
support moderate destabilization, and thunderstorm clusters are
expected to develop over higher terrain. Vertical shear will be
weak, limiting organized convection. Nevertheless, wet microbursts
could produce sporadic strong/locally damaging wind gusts.
..Leitman.. 08/26/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1135 AM CDT Wed Aug 26 2026
Valid 261700Z - 271200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHEASTERN
CALIFORNIA...NORTHWESTERN NEVADA...AND SOUTHEASTERN OREGON...
As an upper trough impinges upon the Pacific Northwest this
afternoon, strong southwesterly flow aloft will support an expansive
fire weather threat across the northern Intermountain West. A
tightening surface pressure gradient along the Cascades and emerging
surface low will compel sustained southwest winds of 10-15 mph
(gusts of 20-30 mph in terrain-favored areas) and RH values of
15-20% in the Columbia Basin and northern Sierra Nevada. A region of
critical conditions are likely across northeastern California,
northwestern NV, and southeastern Oregon where RH values will
decline to less than 15% and sustained southwest winds increase to
20 mph. Notably, in the last 48 hours, numerous lightning strikes
occurred with minimally observed precipitation (less than 0.15")
within today's Critical risk area and southern extent of the
Elevated highlights, increasing concerns for holdovers to emerge.
Fuels remain receptive across much of the region, with active fires
in the landscape and observed ERCs ranging from the 90-95th
percentile.
12z REFS/HREF continue to depict 50-60% probabilities of
thunderstorms across the Northern Rockies this afternoon. Forecast
soundings portray deep inverted-V profiles, MUCAPE vales up to 1200
J/kg, and LCL-EL winds of 25-35 kt; as a result, accumulating
precipitation at the surface is expected to be minimal, escalating
the potential for lightning-induced ignitions within an increasingly
receptive fuelscape. Isolated Dry Thunderstorm highlights were
trimmed out of far northeastern Washington where afternoon
thunderstorms have become less probable.
Farther south, offshore winds will redevelop this evening in
portions of southern California. Elevated fire weather conditions
are expected in favored terrain gaps and downslope areas of
LA/Ventura/Santa Barbara counties. Please see the previous
discussion for more details.
..Elizalde-Garcia.. 08/26/2026
.PREV DISCUSSION... /ISSUED 0107 AM CDT Wed Aug 26 2026/
...Synopsis...
An upper-level trough edging into the Pacific Northwest will bring
widespread fire weather concerns to much of the interior of the
Northwest, northern Great Basin and northern Rockies today. Isolated
dry thunderstorms are expected across much of the northern Rockies,
while dry and breezy conditions develop farther west across the
Columbia Basin south towards the northern Great Basin and
northeastern CA. An increasing offshore pressure gradient will bring
an elevated fire weather threat to parts of southern CA late this
afternoon into the overnight hours as dry and breezy conditions
develop.
...Northeastern California into northwestern Great Basin...
A narrow corridor of critical fire weather conditions is likely
today across the northwestern fringe of the Great Basin. The
upper-level trough and attendant increasing deep layer southwest
flow will support southwest surface winds of around 20 mph. An
existing dry air mass with RH falling to as low as 10% and receptive
fuels will promote wildfire spread, where several active fires are
present.
...Columbia Basin southward towards the northern Great Basin and
northern Sierra Nevada...
An upper trough encroaching upon the Pacific Northwest will
strengthen mid-level southwest winds across much of the northwestern
U.S. today. Although upper-level cloud cover will inhibit full
mixing potential across the region, the deep-layer southwest flow
aided by an emerging surface low across eastern WA/OR will
contribute to southwest winds of 10-15 mph from northeastern CA into
eastern OR and the Columbia Basin. Relative humidity reductions by
peak afternoon heating will likely reach around 15%.
...Northern Rockies into northern Washington...
The approaching upper trough will promote broad but diffuse forcing
for ascent as a mid/upper moisture plume pushes into the northern
Rockies. Afternoon instability (MLCAPE values in the 500-1000 J/kg
range), a dry sub-cloud layer and northeast shower/thunderstorm
trajectories of 25-35 mph with PWATs generally less than 0.8",
should limit surface rainfall this afternoon and evening as isolated
dry thunderstorms develop across the central ID mountains northward
into the ID Panhandle and western MT.
...Southern California...
High pressure aloft will continue to support dry conditions and near
record high temperatures in the 90s and 100s farther inland away
from coastal influence. Fuels continue to dry, becoming increasingly
receptive each day. An offshore pressure gradient will promote
primarily north winds of 15-25 mph amid RH of 15-20% this evening
into early D2/Thursday morning. Winds will be strongest in favored
terrain gaps and downslope areas in LA/Ventura/Santa Barbara
counties.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0213 PM CDT Wed Aug 26 2026
Valid 271200Z - 281200Z
...CRITICAL FIRE WEATHER AREA FOR FAR NORTHEASTERN
CALIFORNIA...NORTHWESTERN NEVADA...SOUTHEASTERN OREGON...
No changes were made to the ongoing forecast. Isolated to scattered
wet/dry thunderstorms are expected to develop over the Northern
Rockies into the adjacent Montana plains on Day 2/Thursday. Fuels
have grown increasingly more receptive, as proven by recently
established wildfires within the landscape. An upgrade to a
Scattered Dry Thunderstorm risk was considered across portions of
the Montana higher-terrain; however, greater moisture influence in
the following days may increase fuel moisture, providing relief to
the environment. In addition, various guidance depicts increasing
mid/high-level clouds in the morning and early afternoon hours,
which could limit solar insolation and thus limit coverage of
afternoon thunderstorms. Nevertheless, lightning ignitions will
remain a concern across much of the outlined region, alongside
strong to severe wind gust potential (see the Day 2 Convective
Outlook for more details). The rest of the forecast remains on
track, please see the previous discussion for more information.
..Elizalde-Garcia.. 08/26/2026
.PREV DISCUSSION... /ISSUED 0111 AM CDT Wed Aug 26 2026/
...Synopsis...
An upper-level trough moving into the Pacific Northwest will bring
an expansive fire weather threat to portions of the Northwestern
U.S., northern Rockies and northern Great Basin. Another round of
isolated dry thunderstorms is expected across the northern Rockies
into the MT high plains Thursday afternoon and evening. Dry and
breezy conditions south of the upper trough will promote fire
weather concerns for the Columbia Basin and much of southwest ID,
southeastern OR and the northern Great Basin. A zone of critical
fire weather conditions are expected across southeastern OR and
adjacent CA/NV where southwest winds will reach 20 mph at times.
...Southeastern Oregon, far northeastern California and adjacent
Nevada...
A corridor of enhanced southwest winds of 15-20 mph with higher
gusts will evolve as deep layer southwesterly flow increases south
of the mid/upper trough moving into the Pacific Northwest. A very
dry boundary layer emerges Thursday amid mostly clear skies, serving
to enhance boundary layer mixing and resultant stronger surface
winds. These winds, relative humidity as low as 10% and dry fuels
will support a rapid fire spread environment across far northeastern
CA, northwestern NV and parts of southeastern OR Thursday afternoon.
The critical fire weather conditions could also impact existing
wildfires within the highlighted area.
...Columbia Basin, northeastern California and northern Great
Basin....
The upper-level trough and associated increasing southwest flow will
continue to push farther into Pacific Northwest Thursday. Downslope
flow east of the Cascades will enhance drying in the Columbia Basin
where RH could reach 15% in some locations. The dry conditions
coupled with west/southwest winds of around 15 mph will promote
elevated fire weather conditions over receptive fuels.
...Northern Rockies...
The aforementioned upper-level trough, sufficient mid-level moisture
and daytime instability will aid in high-based thunderstorm
development once again across the northern Rockies and adjacent high
plains of MT Thursday afternoon/evening. Fast shower/thunderstorm
motions and a dry, sub-cloud layer should limit surface rainfall
accumulation, increasing ignition potential atop a dry fuelscape.
...Southern California...
Hot temperatures in the 90s to lower 100s under an upper high across
southern CA will promote increasingly dry fuels across the region.
An offshore pressure gradient will enhance mainly northerly winds,
particularly Thursday evening/night across wind prone areas of
LA/Ventura/Santa Barbara counties, leading to an elevated fire
weather threat.
...Please see www.spc.noaa.gov/fire for graphic product...
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