Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 811

May 30, 202124 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at May 30, 2021, 3:37 PM CDT for 24 counties in Minnesota. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued: May 30, 2021, 3:37 PM CDT (20:37 UTC)
Expired: May 30, 2021, 5:30 PM CDT
In force: 113 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 5%

All 24 counties

Aitkin County, MN, Becker County, MN, Beltrami County, MN, Benton County, MN, Cass County, MN, Clay County, MN, Clearwater County, MN, Crow Wing County, MN, Douglas County, MN, Hubbard County, MN, Itasca County, MN, Koochiching County, MN, Lake of the Woods County, MN, Mahnomen County, MN, Mille Lacs County, MN, Morrison County, MN, Norman County, MN, Otter Tail County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Saint Louis County, MN, Todd County, MN, Wadena County, MN

The radar

The Duluth radar (KDLH), 147 km from the middle of the area, began a volume at 20:40 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, 8.6 hours before the alert went out and 187 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 821 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 63 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

805 
ACUS11 KWNS 302037
SWOMCD
SPC MCD 302037 
MNZ000-302230-

Mesoscale Discussion 0811
NWS Storm Prediction Center Norman OK
0337 PM CDT Sun May 30 2021

Areas affected...Northern/central Minnesota

Concerning...Severe potential...Watch unlikely 

Valid 302037Z - 302230Z

Probability of Watch Issuance...5 percent

SUMMARY...Small hail and possibly strong, gusty winds this
afternoon. The threat will diminish by sunset. No WW expected.

DISCUSSION...Temperatures of around -21 C were observed at 500 mb on
this morning's INL sounding. With the mid-level trough sinking
southeastward today, temperatures have likely cooled aloft further.
Weak buoyancy has developed along and ahead of a weak cold front in
northwestern Minnesota. A few thunderstorms have developed within
the last several hours, but have mainly been weak and low-topped. As
peak heating nears, a few storms may deepen enough to pose a
marginal severe threat. Limited moisture/buoyancy should generally
keep hail sub-severe. However, the surface dewpoint/temperature
spreads (approximately 20-30 F) will allow some stronger outflow
winds to develop. These gusts are also liable to stay sub-severe at
35-45 kts. No WW is expected.

..Wendt/Goss.. 05/30/2021

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

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

LAT...LON   46049602 47249678 48329640 48979426 48509217 47979158
            47599163 46969232 46179338 45739381 45569435 45739508
            46049602

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.