Alert archive / Indiana / Mesoscale Discussions in 2021
Mesoscale Discussion 1990
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 7:18 PM CST for 24 counties in Illinois; 43 counties in Indiana. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 7:18 PM CST (01:18 UTC)
- Expired
- Dec 10, 2021, 8:45 PM CST
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 95%
All 67 counties
Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Ford County, IL, Iroquois County, IL, Jasper County, IL, Lawrence County, IL, Logan County, IL, Macon County, IL, McLean County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Bartholomew County, IN, Benton County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Decatur County, IN, Delaware County, IN, Fountain County, IN, Grant County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Jackson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Orange County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Rush County, IN, Shelby County, IN, Sullivan County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, White County, IN
The radar
The Indianapolis radar (KIND), 102 km from the middle of the area, began a volume at 01:20 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 1.3 hours before the alert went out and 108 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
- 119 J/kg
- Mixed-layer CIN
- -33 J/kg
- Mixed-layer LCL
- 662 m above ground
- 0-6 km bulk shear
- 73 kt
- 0-1 km storm-relative helicity
- 341 m²/s²
- 0-3 km storm-relative helicity
- 357 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
757
ACUS11 KWNS 110119
SWOMCD
SPC MCD 110118
INZ000-ILZ000-110245-
Mesoscale Discussion 1990
NWS Storm Prediction Center Norman OK
0718 PM CST Fri Dec 10 2021
Areas affected...Central and Eastern Illinois and western and
central Indiana.
Concerning...Severe potential...Watch likely
Valid 110118Z - 110245Z
Probability of Watch Issuance...95 percent
SUMMARY...A tornado watch will be needed within the next hour across
portions of Illinois and Indiana.
DISCUSSION...A broken line of supercells has developed across
eastern Missouri and will move into central Illinois and eventually
Indiana during the overnight hours. Dewpoints are only in the mid to
upper 50s across Indiana and eastern Illinois at this time which
yields limited instability in the region. However, the strong
low-level jet will continue to advect low-level moisture northward
with the 00Z HRRR showing low 60s dewpoints advecting northward
ahead of the storms as they move into Indiana. This will yield
MLCAPE between 500 and 1000 J/kg. This instability combined with an
extremely favorable wind field (90 knots of 0-6 km shear and over
600 m2/s2 0 to 1 km SRH per ILX VWP) should continue a significant
severe weather threat through the overnight hours with primary
threats of damaging winds and tornadoes (a few of which may be
strong). A tornado watch will be needed within the hour to cover
this threat.
..Bentley/Grams.. 12/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LMK...IWX...IND...PAH...LOT...ILX...LSX...
LAT...LON 40478989 40848822 40988709 40408520 39518538 38778563
38468670 38508801 38608876 40478989SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 7:02 PM CST | Mesoscale Discussion | SPC | Calhoun, Greene, Jersey, Macoupin, Madison, Monroe and 4 more | 58 min |
| Dec 10, 7:47 PM CST | Tornado Watch | SPC | Champaign, Clark, Clay, Coles, Crawford, Cumberland and 21 more | 8 hr |
| Dec 10, 8:53 PM CST | Mesoscale Discussion | SPC | Bond, Champaign, Christian, Clark, Clay, Coles and 21 more | 97 min |
| Dec 10, 9:36 PM CST | Mesoscale Discussion | SPC | Clark, Coles, Cumberland, Edgar, Effingham, Shelby | 54 min |
| Dec 10, 10:09 PM CST | Mesoscale Discussion | SPC | Massac | 96 min |
| Dec 10, 11:03 PM CST | Tornado Watch | SPC | Alexander, Clinton, Edwards, Fayette, Franklin, Gallatin and 17 more | 5 hr |
| Dec 10, 11:28 PM CST | Mesoscale Discussion | SPC | Alexander, Clark, Clay, Coles, Crawford, Cumberland and 24 more | 92 min |
| Dec 10, 6:21 PM CST | Tornado Watch | SPC | Clark, Crawford, Dubois, Floyd, Harrison, Jefferson and 4 more | 10 hr |
| Dec 10, 8:35 PM CST | Mesoscale Discussion | SPC | Harrison | 85 min |
| Dec 10, 10:25 PM CST | Mesoscale Discussion | SPC | Bartholomew, Benton, Blackford, Boone, Brown, Carroll and 50 more | 95 min |
| Dec 10, 11:08 PM CST | Mesoscale Discussion | SPC | Dearborn, Decatur, Delaware, Fayette, Franklin, Hamilton and 16 more | 67 min |
| Dec 10, 11:20 PM CST | Tornado Watch | SPC | Adams, Allen, Blackford, Carroll, Cass, Dearborn and 27 more | 6 hr |
| Dec 11, 1:46 AM CST | Mesoscale Discussion | SPC | Bartholomew, Brown, Daviess, Dearborn, Decatur, Delaware and 21 more | 59 min |
Nearby
Mesoscale Discussions in Indiana, 2021Mesoscale Discussions in Illinois, 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.