Alert archive / Montana / Mesoscale Discussions in 2026

Mesoscale Discussion 1521

July 6, 20266 counties in Montana; 5 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 6, 2026, 12:36 AM MDT for 6 counties in Montana; 5 counties in North Dakota. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Jul 6, 2026, 12:36 AM MDT (06:36 UTC)
Expired
Jul 6, 2026, 2:30 AM MDT
In force
114 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Dawson County, MT, Fallon County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Wibaux County, MT, Burke County, ND, Divide County, ND, Golden Valley County, ND, McKenzie County, ND, Williams County, ND

The radar

The Glasgow radar (KGGW), 205 km from the middle of the area, began a volume at 06:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 6.6 hours before the alert went out and 203 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Glasgow Intl Airport, MT at 00:00Z on 2026-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 255 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Glasgow Intl Airport, MT at 00:00Z on 2026-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -32 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
255 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
2787 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-32 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

340 
ACUS11 KWNS 060636
SWOMCD
SPC MCD 060636 
NDZ000-MTZ000-060830-

Mesoscale Discussion 1521
NWS Storm Prediction Center Norman OK
0136 AM CDT Mon Jul 06 2026

Areas affected...Parts of eastern MT into western ND

Concerning...Severe potential...Watch unlikely 

Valid 060636Z - 060830Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong to severe storms are possible through the
early morning.

DISCUSSION...Scattered storms are ongoing early this morning across
parts of eastern MT, in association with a mid/upper-level shortwave
trough and attendant cold front. While this convection is likely
somewhat elevated, steep midlevel lapse rates atop relatively rich
low-level moisture are resulting in MUCAPE of 1500-2500 J/kg (per
recent objective mesoanalyses), with sufficient effective bulk shear
for some storm organization. This thermodynamic environment will
favor some hail threat, especially with any longer-lived
semi-discrete cells. Low-level nocturnal stabilization may limit the
severe-wind threat to some extent, but isolated strong to severe
gusts may still accompany the strongest downdrafts. The isolated
severe threat may spread into parts of western ND with time early
this morning.

..Dean/Mosier.. 07/06/2026

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

ATTN...WFO...BIS...BYZ...GGW...

LAT...LON   46520370 46210448 46540510 47760545 48440518 48970431
            49270288 49040226 48410245 46520370 

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 5, 7:10 PM MDTMesoscale DiscussionSPCCuster, Dawson, Fallon, Fergus, Garfield, McCone and 7 more2 hr
Jul 5, 8:38 PM MDTMesoscale DiscussionSPCDunn, McHenry, McLean, Mercer, Stark, Ward97 min
Jul 6, 12:11 PM MDTMesoscale DiscussionSPCCass, Grand Forks, Ransom, Richland, Sargent, Steele and 1 more2 hr
Jul 6, 12:40 PM MDTSevere Thunderstorm WatchSPCBarnes, Cass, Grand Forks, Ransom, Richland, Sargent and 2 more7 hr
Jul 6, 5:02 PM MDTMesoscale DiscussionSPCCass, Ransom, Richland, Sargent58 min

Nearby

Mesoscale Discussions in Montana, 2026Mesoscale Discussions in North Dakota, 2026Every mesoscale discussion in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.