Alert archive / Wisconsin / Mesoscale Discussions in 2021
Mesoscale Discussion 1989
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 7:04 PM CST for 23 counties in Minnesota; 29 counties in Wisconsin. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 7:04 PM CST (01:04 UTC)
- Expired
- Dec 11, 2021, 1:00 AM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
All 52 counties
Anoka County, MN, Blue Earth County, MN, Brown County, MN, Carver County, MN, Chisago County, MN, Cottonwood County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Isanti County, MN, Le Sueur County, MN, McLeod County, MN, Nicollet County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Washington County, MN, Watonwan County, MN, Wright County, MN, Barron County, WI, Buffalo County, WI, Burnett County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Forest County, WI, Jackson County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Price County, WI, Rusk County, WI, Saint Croix County, WI, Sawyer County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vilas County, WI, Washburn County, WI, Wood County, WI
The radar
The La Crosse radar (KARX), 103 km from the middle of the area, began a volume at 01:04 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
Minneapolis, MN (KMPX), launched 00:00Z, 1.1 hours before the alert went out and 151 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
- 534 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 123 m²/s²
- 0-3 km storm-relative helicity
- 243 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
958
ACUS11 KWNS 110105
SWOMCD
SPC MCD 110104
MIZ000-WIZ000-MNZ000-110700-
Mesoscale Discussion 1989
NWS Storm Prediction Center Norman OK
0704 PM CST Fri Dec 10 2021
Areas affected...portions of southern Minnesota into northern
Wisconsin
Concerning...Heavy snow
Valid 110104Z - 110700Z
SUMMARY...1-2 inch/hr snowfall rates are expected in the heavier
snow bands across southern Minnesota into northern Wisconsin for the
next several hours.
DISCUSSION...A surface low centered across northwest MO continues to
track northeast in tandem with a positively-tilted mid-level trough
and upper-level jet streak, promoting widespread deep-layer ascent
across the Upper Mississippi Valley. Deep low to mid-level moisture
continues to advect north-northwestward within a warm-conveyer belt,
evident via widespread ongoing rain/wintry precipitation, which is
wrapping around the northern periphery of the low across central
MN/WI. The deep moisture continues to ascend via strong 925-700 mb
WAA while pivoting northwestward around the low, where 00Z
mesoanalysis depicts strong 700 mb frontogenesis. In the 700 mb
frontogenesis zone, near-saturated to saturated air is expected to
continue rapidly ascending within a deep, sub-freezing tropospheric
layer, where heavy snow has already been reported. As such, 1-2
inch/hr snowfall rates will likely continue across portions of
central MN into WI for several more hours.
..Squitieri/Grams.. 12/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...GRB...DLH...ARX...MPX...FSD...
LAT...LON 43799569 44369512 45319401 46059205 46078938 45798823
45328760 45028745 44798847 44628910 44349000 44219093
43999322 43699497 43669535 43799569Nearby
Mesoscale Discussions in Wisconsin, 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.