Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 1372

July 28, 20216 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Jul 28, 2021, 10:28 AM CDT for 6 counties in Minnesota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 28, 2021, 10:28 AM CDT (15:28 UTC)
Expired: Jul 28, 2021, 12:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Aitkin County, MN, Beltrami County, MN, Cass County, MN, Clearwater County, MN, Hubbard County, MN, Itasca County, MN

The radar

The Duluth radar (KDLH), 178 km from the middle of the area, began a volume at 15:31 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

International Fa, MN (KINL), launched 12:00Z, 3.5 hours before the alert went out and 137 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 285 J/kg
Mixed-layer CIN: -422 J/kg
Mixed-layer LCL: 1229 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 190 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

572 
ACUS11 KWNS 281529
SWOMCD
SPC MCD 281528 
MNZ000-281730-

Mesoscale Discussion 1372
NWS Storm Prediction Center Norman OK
1028 AM CDT Wed Jul 28 2021

Areas affected...Northeast/North-Central MN

Concerning...Severe potential...Watch unlikely 

Valid 281528Z - 281730Z

Probability of Watch Issuance...20 percent

SUMMARY...Strong to severe thunderstorms capable of large hail are
possible over the next few hours across north-central/northeast MN.

DISCUSSION...Two strong updrafts have recently developed within the
warm air advection regime across northeast MN. The environment over
the region is characterized by steep mid-level lapse rates and
strong low-level stability below about 750-700 mb. Above this layer,
enough moisture is in place to limit convective inhibition and
provide modest buoyancy. Additionally, strong northwesterly flow
exists above 750-700 mb, supporting rotation/organization if
updrafts can be maintained. The ongoing severe storms are evidence
of this scenario. The air mass downstream of these storms across the
MN Arrowhead is not as buoyant, but the organized character of these
storms suggests that the threat for large hail may exist with these
two storms for the next hour or two. 

Additional storm development appears possible back farther west
across more of north-central MN where some deeper cumulus is
currently clustered. As with the ongoing storms, any additional
development would pose a threat for large hail.

..Mosier/Hart.. 07/28/2021

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

ATTN...WFO...DLH...FGF...

LAT...LON   47979576 48349521 48429439 48159378 47729298 47139240
            46559289 46499350 46899507 47329576 47979576

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 27, 7:33 PM CDT	Mesoscale Discussion	SPC	Dakota, Dodge, Fillmore, Freeborn, Goodhue, Houston and 8 more	87 min
Jul 27, 8:03 PM CDT	Severe Thunderstorm Watch	SPC	Dakota, Dodge, Fillmore, Freeborn, Goodhue, Houston and 8 more	6 hr
Jul 27, 10:35 PM CDT	Mesoscale Discussion	SPC	Dodge, Fillmore, Houston, Mower, Olmsted, Winona	55 min
Jul 28, 2:48 AM CDT	Mesoscale Discussion	SPC	Big Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 12 more	2 hr
Jul 28, 12:59 PM CDT	Mesoscale Discussion	SPC	Koochiching, Lake, Lake of the Woods, Saint Louis	2 hr
Jul 28, 3:32 PM CDT	Mesoscale Discussion	SPC	Beltrami, Clearwater, Lake of the Woods, Mahnomen, Red Lake	118 min
Jul 28, 5:09 PM CDT	Mesoscale Discussion	SPC	Aitkin, Anoka, Benton, Carlton, Chisago, Crow Wing and 7 more	2 hr

Nearby

Mesoscale Discussions in Minnesota, 2021 Every mesoscale discussion in 2021

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.