Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1958
The Storm Prediction Center issued this mesoscale discussion at Dec 5, 2021, 11:33 AM CST for 4 counties in Minnesota; Bayfield County, Wisconsin. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 5, 2021, 11:33 AM CST (17:33 UTC)
- Expired
- Dec 5, 2021, 2:30 PM CST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
Counties Cook County, MN, Itasca County, MN, Lake County, MN, Saint Louis County, MN, Bayfield County, WI
The radar
The Duluth radar (KDLH), 62 km from the middle of the area, began a volume at 17:40 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, 5.6 hours before the alert went out and 153 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1001 m above ground
- 0-6 km bulk shear
- 67 kt
- 0-1 km storm-relative helicity
- 60 m²/s²
- 0-3 km storm-relative helicity
- 73 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
258
ACUS11 KWNS 051733
SWOMCD
SPC MCD 051733
MIZ000-MNZ000-WIZ000-052030-
Mesoscale Discussion 1958
NWS Storm Prediction Center Norman OK
1133 AM CST Sun Dec 05 2021
Areas affected...Northeast Minnesota and far northern Wisconsin.
Concerning...Heavy snow
Valid 051733Z - 052030Z
SUMMARY...A broad region of moderate snow is expected to continue
across northeast Minnesota and northern Wisconsin through the
afternoon with heavy snow in a region of lake enhancement near the
western shore of Lake Superior.
DISCUSSION...Moderate snow has been falling for most of the morning
across northeast Minnesota and far northern Wisconsin. Recently
heavier snow has developed in St. Louis, Lake, and Cook counties in
Minnesota where enhancement from Lake Superior has increased
snowfall rates. Continued east-southeasterly surface flow and
isentropic ascent is expected to continue through the afternoon with
similar conditions expected for another 4 to 6 hours. Expect
snowfall rates around 1 to 1.5 inches per hour across much of the
region with higher rates possibly over 2 inches per hour where lake
enhancement is occurring.
..Bentley.. 12/05/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...DLH...
LAT...LON 48089301 48169060 47958965 46968942 46539040 46649236
46889357 47099411 47359427 47589429 48089301SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 4, 9:43 PM CST | Mesoscale Discussion | SPC | Clay, Norman | 4 hr |
| Dec 5, 4:22 AM CST | Mesoscale Discussion | SPC | Aitkin, Carlton, Cass, Itasca, Lake, Saint Louis | 6 hr |
Nearby
Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in Wisconsin, 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.