Mesoscale Discussion 2171
NWS Storm Prediction Center Norman OK
0608 PM CDT Sat Aug 29 2026

Areas affected...Western into central Nebraska and southwestern
South Dakota

Concerning...Severe potential...Watch unlikely 

Valid 292308Z - 300115Z

Probability of Watch Issuance...20 percent

SUMMARY...A line of loosely organized thunderstorms has produced
several severe gusts over the past couple of hours. Recent
radar/lightning trends have shown some weakening, though a few
severe gusts remain possible into early evening. A watch is not
currently expected.

DISCUSSION...A line of thunderstorms, with only isolated deeper
convective cores, has continued to produce severe wind gusts in the
55-75 mph range over the past couple of hours. As this line
continues east this evening, it will encounter a drier pocket of air
where dewpoints have been mixing out late this afternoon. Farther
east, in central Nebraska/South Dakota, dewpoints are in the
mid/upper 60s F. MRMS CAPPI data suggests the strongest cores are
losing definition as they encounter weaker buoyancy/greater MLCIN.
Though a modest increase in the low-level jet will occur this
evening, it is unclear if these storms will maintain organization
more than an hour or two given otherwise poor synoptic support. A
few severe wind gusts are possible with this activity.

..Wendt/Guyer.. 08/29/2026

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

ATTN...WFO...LBF...UNR...CYS...

LAT...LON   41740363 41830358 42120342 42790335 43170366 43420180
            43320105 42930082 42200096 41740154 41600205 41740363 

MOST PROBABLE PEAK WIND GUST...65-80 MPH

Mesoscale Discussion 2170
NWS Storm Prediction Center Norman OK
0604 PM CDT Sat Aug 29 2026

Areas affected...far eastern NV into central and northern UT

Concerning...Severe potential...Watch possible 

Valid 292304Z - 300100Z

Probability of Watch Issuance...40 percent

SUMMARY...Large hail and severe gusts may accompany the stronger
cells through 7-8pm MDT.

DISCUSSION...Latest radar mosaic shows a few cells, the most notable
of which are moving east over White Pine Co. NV and Juab Co. UT. 
Ample deep-layer shear (50 kt) and moderate buoyancy (1000-1500 J/kg
SBCAPE) are favoring storm organization into stronger updraft/cell
development.  Despite some cloud cover and minor influence from
earlier day convection, the optimal time-of-day via peak heating and
steepening of low-level lapse rates downstream of the ongoing storm
activity, likely promotes a maintenance of the severe threat with
the stronger storms for the next few hours.

..Smith.. 08/29/2026

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

ATTN...WFO...SLC...LKN...

LAT...LON   39401424 39611446 40361454 40691423 41231222 41021170
            39841121 39551133 39371169 39401424 

MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0249 PM CDT Sat Aug 29 2026

Valid 292000Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEVERE
THUNDERSTORMS FROM EASTERN NEVADA ACROSS NORTHERN UTAH INTO FAR
SOUTHWEST WYOMING...

...SUMMARY...
Widely scattered strong to severe storms are expected across parts
of the northern Great Basin, northern/central Rockies, and northern
Plains. Severe wind gusts are the main threat.

...20z Update...
No changes are needed to the current D1 Convective Outlook. See MCDs
#2167, #2168, and the previous discussion below for more
information.

..Thornton.. 08/29/2026

.PREV DISCUSSION... /ISSUED 1129 AM CDT Sat Aug 29 2026/

...Great Basin through the central Rockies...
Enhanced mid-level southwesterly flow aloft exists between the upper
ridging centered over the southern High Plains and a shortwave
trough moving through the Pacific Northwest. 12Z SLC sounding
sampled this enhanced flow well, reporting a belt of 50-55 kt wind
around 600 to 500 mb. This sounding also sampled the increased
mid-level moisture within this belt of stronger flow, resulting
precipitable water over 1.1".

Modest heating of this airmass is expected to foster moderate
buoyancy, although the widespread cloudiness could keep the airmass
from fully destabilizing. Most RAP soundings across the region
maintain lingering convective inhibition from UT into southern WY.
Even so, the combination of modest buoyancy, mid-level moisture, and
ascent attendant to a low-amplitude shortwave trough progressing
through the region will support scattered to numerous thunderstorms
from eastern NV across UT into northwest CO/southern WY. Some
isolated hail is possible with the strongest cores (which could
briefly acquire supercellular characteristics), but the primary
severe risk is strong to severe wind gusts. Highest severe coverage
is still expected from east-central NV into northern UT where the
greatest afternoon buoyancy is forecast.

...Northeast CO/eastern WY/NE Panhandle into the western/central
Dakotas...
High-based showers and thunderstorms along the leading edge of the
strongest ascent attendant to the shortwave trough moving through
the Great Basin and central Rockies should emerge into a diurnally
destabilized and moderately buoyant airmass from northeast CO into
eastern WY and the NE Panhandle during the late afternoon/early
evening. This could result in reintensification, and a risk for both
large hail and damaging gusts across the region throughout the
evening. Most of the guidance was overly aggressive with
destabilization and buoyancy across this region yesterday, and there
is some concern that cloud cover could again limit heating. That
being said, there is a pocket of greater low-level moisture across
SD and the region is currently under widely scattered cloud cover.
Enhanced westerly flow atop low-level easterlies will support at
least moderate deep-layer shear, so any updrafts that can mature
should be able to organize, with an attendant risk for large hail
and damaging gusts.

...AZ...
12Z PHX sounding sampled moderate mid-level moisture atop warm and
dry low levels. Scattered thunderstorm development is anticipated
across much of the region. Vertical shear is weak and a largely
disorganized storm mode is anticipated. Still, given the high storm
bases and steep low-level lapse rates, isolated strong to severe
gusts are possible this afternoon and evening.

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0234 PM CDT Sat Aug 29 2026

Valid 311200Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
HIGH PLAINS TO PARTS OF THE CORN BELT...

...SUMMARY...
Isolated severe thunderstorms, accompanied by wind and hail, are
possible Monday afternoon from the central High Plains toward parts
of the Corn Belt.

...Discussion...
On Monday, a shortwave trough will lift northeastward out of the
Northern Plains, with an upper high over the Mid MS/Lower OH
Valleys. To the west, an upper low will drop southward off the West
Coast, with increasing southwest flow aloft from CA into the Great
Basin late. A leading wave is also forecast to develop over the
central Rockies, moving from CO into NE overnight.

At the surface, a quasi-stationary boundary will extend from NE/SD
into southern MN/WI, where 60s to 70s F dewpoints will exist.
Conditionally, this region could support a severe risk. However, the
departing upper wave combined veering and weakening low-level winds
suggest minimal storm coverage for most of the period. Some forecast
soundings also indicate shallow boundary layer moisture. However,
isolated storms cannot be ruled out both during the day and
overnight within this moist zone, therefore will maintain low severe
probabilities.

Scattered strong to severe storms may also occur over the Central
High Plains, where a lee trough will develop and where a developing
midlevel wave is forecast. Strong heating as well as 50s to near 60
F dewpoints will support scattered late afternoon storms from
eastern CO/southeast WY, spreading northeast into NE. A few severe
gusts or marginal hail will be possible.

..Jewell.. 08/29/2026