Alert archive / Iowa / Mesoscale Discussions in 2021
Mesoscale Discussion 2034
The Storm Prediction Center issued this mesoscale discussion at Dec 15, 2021, 5:16 PM CST for 36 counties in Iowa; Faribault County, Freeborn County, Martin County, Minnesota. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Dec 15, 2021, 5:16 PM CST (23:16 UTC)
- Expired
- Dec 15, 2021, 7:15 PM CST
- In force
- 119 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 563
All 39 counties
Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Clarke County, IA, Clay County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Franklin County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Kossuth County, IA, Madison County, IA, O'Brien County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Ringgold County, IA, Sac County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA, Faribault County, MN, Freeborn County, MN, Martin County, MN
The radar
The Des Moines radar (KDMX), 64 km from the middle of the area, began a volume at 23:19 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
Omaha, NE (KOAX), launched 12:00Z, 11.3 hours before the alert went out and 180 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
- 2165 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 346 m²/s²
- 0-3 km storm-relative helicity
- 384 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
305
ACUS11 KWNS 152316
SWOMCD
SPC MCD 152316
IAZ000-MNZ000-MOZ000-160115-
Mesoscale Discussion 2034
NWS Storm Prediction Center Norman OK
0516 PM CST Wed Dec 15 2021
Areas affected...much of central and northern Iowa...far southern
Minnesota
Concerning...Tornado Watch 563...
Valid 152316Z - 160115Z
The severe weather threat for Tornado Watch 563 continues.
SUMMARY...Damage is likely to occur in association with a rapidly
moving line of storms across Iowa, northern Missouri, and eventually
far southern Minnesota, with a few fast-moving tornadoes possible as
well.
DISCUSSION...A particularly damaging line of storms currently
extends from a low over northwest IA southward into northwest MO and
eastern KS, and is moving east/northeast at 75-85 mph. Several
measured sig-severe wind gusts have been measured recently, and this
is likely to continue. Further, effective SRH currently ranges from
400-600 m2/s2 across western IA and points south, suggesting brief,
but possibly fast-moving embedded QLCS tornadoes are clearly a
threat. Destabilization due to the spread of a moist air mass will
eventually occur over southern MN behind a diffuse warm front, and
tornadoes will be a concern as the low continues to deepen.
..Jewell.. 12/15/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...DMX...EAX...FSD...OAX...
LAT...LON 40719490 41329482 41839497 42529526 42949570 42999574
43409534 43799466 44029337 43789311 43109308 42209314
41509318 40999345 40709392 40499447 40489471 40569492
40719490SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 15, 12:28 PM CST | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Boone, Buena Vista and 59 more | 2 hr |
| Dec 15, 1:23 PM CST | Tornado Watch | SPC | Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 64 more | 7 hr |
| Dec 15, 3:55 PM CST | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 40 more | 95 min |
| Dec 15, 4:51 PM CST | Mesoscale Discussion | SPC | Allamakee, Benton, Black Hawk, Bremer, Buchanan, Cedar and 24 more | 114 min |
| Dec 15, 5:30 PM CST | Tornado Watch | SPC | Allamakee, Benton, Buchanan, Cedar, Chickasaw, Clayton and 23 more | 6 hr |
Nearby
Mesoscale Discussions in Iowa, 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.