Alert archive / North Dakota / Mesoscale Discussions in 2021
Mesoscale Discussion 1956
The Storm Prediction Center issued this mesoscale discussion at Dec 4, 2021, 9:43 PM CST for Clay County, Norman County, Minnesota; 17 counties in North Dakota. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 4, 2021, 9:43 PM CST (03:43 UTC)
- Expired
- Dec 5, 2021, 1:45 AM CST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
Counties Clay County, MN, Norman County, MN, Barnes County, ND, Benson County, ND, Cass County, ND, Eddy County, ND, Foster County, ND, Griggs County, ND, Kidder County, ND, McHenry County, ND, McLean County, ND, Nelson County, ND, Pierce County, ND, Sheridan County, ND, Steele County, ND, Stutsman County, ND, Traill County, ND, Ward County, ND, Wells County, ND
The radar
The Bismarck radar (KBIS), 137 km from the middle of the area, began a volume at 03:46 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
Bismarck Municip, ND (KBIS), launched 00:00Z, 3.7 hours before the alert went out and 133 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
- 622 m above ground
- 0-6 km bulk shear
- 104 kt
- 0-1 km storm-relative helicity
- 225 m²/s²
- 0-3 km storm-relative helicity
- 683 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
917
ACUS11 KWNS 050343
SWOMCD
SPC MCD 050343
MNZ000-NDZ000-050745-
Mesoscale Discussion 1956
NWS Storm Prediction Center Norman OK
0943 PM CST Sat Dec 04 2021
Areas affected...Central and eastern North Dakota
Concerning...Heavy snow
Valid 050343Z - 050745Z
SUMMARY...A zone of around 1 inch per hour snowfall rates is
probable within the next 1-4 hours in parts of central and eastern
North Dakota.
DISCUSSION...A broad zone of snowfall has continued to develop
within a warm advection zone across much of North Dakota into
west-central Minnesota. A subtle shortwave trough is becoming more
evident on water vapor satellite imagery in the MT/ND border
vicinity. This feature is forecast to dig southward this evening. As
this occurs, increasing mid-level ascent will couple with the
850-700 mb warm advection zone to produce areas of higher snowfall
rates over the next 1-4 hours. The modest mid-level ascent suggests
that snowfall rates of around 1 inch per hour will generally be the
peak for the event. However, localized higher rates up to 1.5 inches
per hour could briefly occur, particularly in east-central North
Dakota.
..Wendt.. 12/05/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...BIS...
LAT...LON 47490170 48010221 48550136 48169827 47599645 47109631
46469656 46429699 46749923 46970009 47490170SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 5, 4:22 AM CST | Mesoscale Discussion | SPC | Aitkin, Carlton, Cass, Itasca, Lake, Saint Louis | 6 hr |
| Dec 5, 11:33 AM CST | Mesoscale Discussion | SPC | Cook, Itasca, Lake, Saint Louis | 3 hr |
Nearby
Mesoscale Discussions in North Dakota, 2021Mesoscale 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.