Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 2040

December 15, 20216 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Dec 15, 2021, 10:43 PM CST for 6 counties in Minnesota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Dec 15, 2021, 10:43 PM CST (04:43 UTC)
Expired
Dec 16, 2021, 4:45 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
Concerning
Blizzard

Counties Aitkin County, MN, Cass County, MN, Hubbard County, MN, Itasca County, MN, Koochiching County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 137 km from the middle of the area, began a volume at 04:46 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 00:00Z, 4.7 hours before the alert went out and 111 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, International Fa, MN at 00:00Z on 2021-12-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, International Fa, MN at 00:00Z on 2021-12-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
499 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

622 
ACUS11 KWNS 160444
SWOMCD
SPC MCD 160443 
MNZ000-161045-

Mesoscale Discussion 2040
NWS Storm Prediction Center Norman OK
1043 PM CST Wed Dec 15 2021

Areas affected...northern Minnesota

Concerning...Blizzard 

Valid 160443Z - 161045Z

SUMMARY...Near-blizzard conditions will develop tonight into
northern Minnesota, with wind gusts of 40-50 mph expected. Snow
rates may reach around 1"/hr.

DISCUSSION...As a deepening surface low tracks northeast toward Lake
Superior tonight, cooling aloft will result in increasingly
favorable profiles for heavy snow from west to east across northern
MN. Forecast soundings show the top of the boundary layer around 870
mb, with maximum boundary layer winds of 40-45 kt. Given expected
precipitation rates, these wind gusts to this magnitude appear
reasonable, resulting in blowing snow and reduced visibilities. The
heaviest snow rates are likely to occur after 06Z and across
northern into northeastern MN.

..Jewell.. 12/16/2021

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

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

LAT...LON   48409197 47839226 46949267 46539336 46489456 46679503
            46919516 47509499 48189470 48669396 48689295 48409197

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 15, 7:11 PM CSTMesoscale DiscussionSPCDodge, Fillmore, Goodhue, Houston, Mower, Olmsted and 3 more2 hr

Nearby

Mesoscale Discussions in Minnesota, 2021Every 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.