SPC MD 1838
MD 1838 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR FAR SOUTHEAST MONTANA...EASTERN WYOMING...FAR WESTERN SOUTH DAKOTA...FAR WESTERN NEBRASKA

Mesoscale Discussion 1838
NWS Storm Prediction Center Norman OK
0622 PM CDT Tue Jul 29 2025

Areas affected...Far Southeast Montana...Eastern Wyoming...Far
Western South Dakota...Far Western Nebraska

Concerning...Severe potential...Watch likely 

Valid 292322Z - 300145Z

Probability of Watch Issuance...80 percent

SUMMARY...A severe threat will likely develop from far southeast
Montana into eastern Wyoming over the next few hours. Isolated large
hail and severe wind gusts will be the primary threats. Weather
watch issuance will likely be needed.

DISCUSSION...Latest surface analysis shows a moist airmass over the
central and northern High Plains, with upslope flow in place from
western Nebraska and western South Dakota into eastern Wyoming.
Surface heating is maximized near a surface trough located in
east-central Wyoming. Scattered thunderstorms, with some severe, are
ongoing near the trough. Short-term model forecasts including the
HRRR, continue to increase convective coverage, suggesting that a
line will develop in far southeast Montana and eastern Wyoming over
the next couple of hours. RAP forecast soundings in eastern Wyoming
early this evening have 0-6 km shear near 40 knots, with 700-500 mb
lapse rates of 8.5 C/km. This environment will support a threat for
large hail and severe gusts with supercells. Intense multicell line
segments may also produce severe wind gusts and hail.

..Broyles/Mosier.. 07/29/2025

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

ATTN...WFO...UNR...CYS...BYZ...RIW...

LAT...LON   45630416 45790467 45770546 45530600 44800605 43540603
            42090606 41420602 41110544 41070463 41170402 41530352
            42190339 43330350 45220397 45630416 

MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN

Read more
https://www.spc.noaa.gov/products/md/md1838.html