Alert archive / Iowa / Mesoscale Discussions in 2021
Mesoscale Discussion 2036
The Storm Prediction Center issued this mesoscale discussion at Dec 15, 2021, 7:11 PM CST for 19 counties in Iowa; 9 counties in Minnesota; 4 counties in Wisconsin. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 15, 2021, 7:11 PM CST (01:11 UTC)
- Expired
- Dec 15, 2021, 9:15 PM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 565
All 32 counties
Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Chickasaw County, IA, Clayton County, IA, Delaware County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Iowa County, IA, Keokuk County, IA, Linn County, IA, Mahaska County, IA, Mitchell County, IA, Poweshiek County, IA, Tama County, IA, Winneshiek County, IA, Dodge County, MN, Fillmore County, MN, Goodhue County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Steele County, MN, Wabasha County, MN, Winona County, MN, Buffalo County, WI, Crawford County, WI, La Crosse County, WI, Trempealeau County, WI
The radar
The La Crosse radar (KARX), 153 km from the middle of the area, began a volume at 01:14 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
Davenport, (KDVN), launched 00:00Z, 1.2 hours before the alert went out and 196 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
- 229 J/kg
- Mixed-layer CIN
- -358 J/kg
- Mixed-layer LCL
- 1061 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 433 m²/s²
- 0-3 km storm-relative helicity
- 496 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
888
ACUS11 KWNS 160112
SWOMCD
SPC MCD 160111
WIZ000-IAZ000-MNZ000-160315-
Mesoscale Discussion 2036
NWS Storm Prediction Center Norman OK
0711 PM CST Wed Dec 15 2021
Areas affected...eastern Iowa...southeast Minnesota...southwest
Wisconsin
Concerning...Tornado Watch 565...
Valid 160111Z - 160315Z
The severe weather threat for Tornado Watch 565 continues.
SUMMARY...The threat for damaging winds and brief tornadoes
continues from Iowa into Wisconsin.
DISCUSSION...A long-lived line of storms with a history of
significant wind damage continues to rapidly move eastward at over
70 mph along a cold front. Meanwhile, a warm front is gradually
lifting north over far southeast MN and into parts of southwest WI.
Forecast soundings from the warm frontal area indicate that a
near-60 F surface dewpoint yields 500-750 J/kg MLCAPE. This,
combined with effective SRH over 500 m2/s2 suggests that storms will
persist across the MN/WI/IA portion of the MS River Valley. Damaging
wind gusts remain likely given the speed of this system as well as
wind magnitude just off the surface, and low-level shear still
supports a QLCS tornado risk.
Farther south across IL and into MO, instability is weaker with more
CIN noted on objective analysis. However, the existing line of
storms will continue to post a damaging wind risk toward the MS
Valley here as well, although the greatest risk remains farther
north where the line is oriented perpendicular to the deep-layer
shear vector.
..Jewell.. 12/16/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DVN...ARX...MPX...DMX...
LAT...LON 41209311 42139279 42789271 43059281 43559332 44039325
44489282 44619224 44489139 44189097 43339085 42459100
41479176 41309202 41159262 41109308 41209311SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 15, 10:43 PM CST | Mesoscale Discussion | SPC | Aitkin, Cass, Hubbard, Itasca, Koochiching, Saint Louis | 6 hr |
| Dec 15, 9:03 PM CST | Mesoscale Discussion | SPC | Barron, Chippewa, Clark, Eau Claire, Forest, Langlade and 14 more | 117 min |
| Dec 15, 9:44 PM CST | Severe Thunderstorm Watch | SPC | Brown, Calumet, Columbia, Dane, Dodge, Door and 22 more | 3 hr |
Nearby
Mesoscale Discussions in Iowa, 2021Mesoscale 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.