Mesoscale Discussion 1872
NWS Storm Prediction Center Norman OK
0708 PM CDT Sat Aug 08 2026

Areas affected...portions of southern and eastern North Dakota into
far northern South Dakota

Concerning...Severe potential...Watch unlikely 

Valid 090008Z - 090145Z

Probability of Watch Issuance...20 percent

SUMMARY...A few instances of severe wind/hail may occur with storms
that can mature over the next few hours. The severe threat should
remain isolated, so a WW issuance is not anticipated.

DISCUSSION...Multicellular storms/possible LP supercells have
attempted to intensify over the past hour. The initial attempts at
stronger convection have produced outflow to the southwest, where
localized convergence is allowing for additional attempts at
initiation to occur. At the moment, it is unclear if these initial
storms will pose the primary threat for severe wind/hail, or if the
greater severe threat will manifest from later storms this evening
(per high-resolution guidance consensus). Uncertainty in convective
evolution is heightened further by the presence of smoke
overspreading the warm sector, which may inhibit convective
development and intensification. 

Nonetheless, under the condition that a thunderstorm should
intensify further and become sustained, the presence of 1000-2500
J/kg MLCAPE amid 50-60 kts of effective bulk shear is adequate in
supporting supercell structures capable of producing severe wind and
hail (with an instance or two of 2+ inch diameter hail possible).

..Squitieri/Mosier.. 08/09/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FGF...ABR...BIS...

LAT...LON   45389890 45610075 45880151 46240181 46530175 46880032
            46939926 46979814 46669765 46039748 45489768 45389890 

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0742 PM CDT Sat Aug 08 2026

Valid 090100Z - 091200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE NORTHERN/CENTRAL PLAINS INTO MN/IA...OVER CENTRAL/SOUTHERN
AZ...AND FROM CENTRAL OH INTO WESTERN NY...

...SUMMARY...
Isolated instances of large to very large hail will be possible
across the northern Plains through tonight.

...Dakotas into MN/IA and the MO Valley...

Isolated thunderstorms have developed early this evening across
south-central ND. Isolated large to very large hail may accompany
these storms if they can intensify and be maintained. It is
uncertain if this convection will continue to develop east/southeast
into SD given strong capping, or if additional convection will
develop later tonight as a low-level jet increases. Reference MCD
1872 for more short term information. Despite uncertainty in
convective evolution through the evening into tonight, severe
potential, mainly in the form of large hail near 2 inch diameter,
and strong wind gusts, remains possible.

...Ohio Valley into western NY...

Thunderstorm clusters have develop ahead of a surface front from OH
into western PA/NY. This activity will continue to spread eastward
within moderate instability through early tonight. Sporadic strong
wind gusts will be possible for a few more hours before weakening
with loss of daytime heating and increasing nocturnal boundary layer
stabilization.

...AZ...

Isolated thunderstorms developing over higher terrain will continue
to spread westward across the lower deserts tonight. Strong wind
gusts will be possible with this activity.

...CO/KS vicinity...

Thick smoke across the region has muted instability across CO into
northeast KS and vicinity. Any stronger convection has moved south
into southwest KS where locally gusty winds are possible for another
couple of hours. However, severe potential appears limited with
anemic high-based showers moving across eastern CO into northwest KS
and southwest NE. As such, severe probabilities have been removed.

...TX...

Outflow from a thunderstorm cluster across northeast TX will
continue to progress south/southwest this evening. Instability
lessens with westward extent and, with loss of daytime heating,
low-level inhibition will increase. Severe potential has largely
diminished and probabilities have been removed.

...NC vicinity...

Thunderstorms have gradually weakened over the past 30-60 minutes as
low-level inhibition increases with the loss of daytime heating. As
such, severe potential has diminished and severe probabilities have
been removed.

..Leitman.. 08/09/2026

Day 3-8 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0541 PM CDT Sat Aug 08 2026

Valid 101200Z - 161200Z

...Synopsis...
Following the flattening of the upper ridge across the northwestern
CONUS, high pressure over the Four Corners will gradually translate
eastward early next week. Residual dry and breezy conditions will
persist across portions of the Great Basin and Wyoming plains
through Day 4/Tuesday, in addition to the southern Plains as high
pressure centers atop the region midweek. Along the northern fringe
of monsoonal moisture where very dry fuels exist, daily chances for
dry thunderstorms will continue as deeper moisture is shunted to the
Desert Southwest and southern Great Basin. Mid to late week,
ensembles indicate a pattern shift with a trough forming off the
West Coast and a shortwave trough approaching the Pacific Northwest,
indicating thunderstorm potential as a result of the overall upper
pattern.  

...Days 3-4/Monday-Tuesday...
...Intermountain West and California Central Valley...
High based convection is likely to evolve on Day 3/Monday on the
northern periphery of deeper monsoonal moisture. PWATs ranging from
0.6-0.8" and daytime instability will likely lead to isolated
high-based thunderstorms across the northern Great Basin, portions
of the Colorado Plateau, and eastern Idaho. 10% probabilities have
been maintained on Day 3/Monday, and may be needed for Day 4/Tuesday
depending on precipitation efficiency early in the forecast period.

Stronger upper-level flow will continue across the flattened ridge,
sustaining a pattern of dry and breezy conditions atop exceptionally
dry fuels. 40% Critical probabilities have been maintained on Day
3/Monday and expanded on Day 4/Tuesday across the northern Great
Basin and Wyoming plains to account for a broader, prolonged fire
weather threat. These conditions could also encourage any
lightning-induced holdovers to emerge, resulting from preceding days
of forecast dry thunderstorms. 

40% Critical highlights have been expanded into portions of the
California Central Valley and adjacent interior Coast Ranges on Day
3/Monday. Despite weak flow aloft, a tightened surface pressure
gradient will induce localized areas of stronger onshore flow where
increasingly receptive fuels exist. 

...Southern High Plains...
Surface low pressure will amplify east of the Colorado Rockies
tightening a surface pressure gradient across the southern Plains,
promoting breezy conditions through Day 4/Tuesday. Hot daytime
temperatures approaching 100+ degrees F amid 10-15% RH values and
sustained southerly surface winds of 15 mph or greater support the
introduction of 40% Critical probabilities. A mixed fuelscape of
live fuels and areas of grass curing (as seen by a 30-day NDVI
comparison) and fuels rebounding from spotty recent rainfall yield a
somewhat complicated environment; however, several preceding days of
elevated fire weather conditions should lead to increasingly more
receptive fuels. 

...Days 5-8...
With cluster analysis and long-range guidance indicating a
significant pattern change across the western CONUS, uncertainty
remains in both the timing and location of the developing eastern
Pacific trough and shortwave troughing entering the Northwest. This
pattern could produce opportunities for much needed moisture across
these regions, or the threat of thunderstorms over an exceptionally
dry fuelscape. Low predictability precludes probabilities at this
time, but may be needed in future outlook cycles as confidence
increases.

..Elizalde-Garcia.. 08/08/2026

...Please see www.spc.noaa.gov/fire for graphic product...