Alert archive / Indiana / Mesoscale Discussions in 2021
Mesoscale Discussion 1036
The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2021, 3:25 PM CDT for 10 counties in Illinois; 26 counties in Indiana. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2021, 3:25 PM CDT (20:25 UTC)
- Expired
- Jun 20, 2021, 5:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 36 counties
Champaign County, IL, Douglas County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kankakee County, IL, Livingston County, IL, Piatt County, IL, Vermilion County, IL, Will County, IL, Benton County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Elkhart County, IN, Fountain County, IN, Fulton County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Tippecanoe County, IN, Wabash County, IN, Warren County, IN, White County, IN, Whitley County, IN
The radar
The Chicago radar (KLOT), 114 km from the middle of the area, began a volume at 20:25 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 12:00Z, 8.4 hours before the alert went out and 128 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
- 193 J/kg
- Mixed-layer CIN
- -275 J/kg
- Mixed-layer LCL
- 1214 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 29 m²/s²
- 0-3 km storm-relative helicity
- 62 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
211
ACUS11 KWNS 202025
SWOMCD
SPC MCD 202025
INZ000-MIZ000-ILZ000-202230-
Mesoscale Discussion 1036
NWS Storm Prediction Center Norman OK
0325 PM CDT Sun Jun 20 2021
Areas affected...Portions of eastern Illinois and northern Indiana
Concerning...Severe potential...Watch possible
Valid 202025Z - 202230Z
Probability of Watch Issuance...60 percent
SUMMARY...There is an increasing severe weather threat late this
afternoon and into the evening from east-central Illinois into
northern Indiana.
DISCUSSION...An MCV has traversed northern Missouri and western
Illinois through the morning and early afternoon today. The
convection has been mostly weak, likely due to the stable, capped
downstream airmass from the overnight MCS in the region. In fact,
almost all lightning has now ended within this cluster. However, a
remnant MCV can still be seen in radar imagery from the KILX
WSR-88D.
The 19Z RAOB from KILX shows the stable airmass with MLCIN near -200
J/kg. However, the hodograph does show decent clockwise curvature
within the lowest 3 km and moderate mid-level flow. This is likely a
good proximity hodograph for later storms which are expected to form
near this MCV later this afternoon/early evening.
Despite the lackluster storm development thus far, this is expected
to change in the next 1 to 2 hours as this MCV moves into east
central Illinois where the airmass was not worked over by overnight
convection. In this region dewpoints are in the low 70s with
temperatures in the mid 80s with the SPC mesoanalysis suggesting
2000 J/kg MLCAPE. This instability, combined with 45 to 50 knots of
effective shear per 19Z ILX RAOB and SPC mesoanalysis should be
sufficient for supercell development. Any supercells which develop
may have a risk of all hazards including a couple of tornadoes. The
tornado threat will likely be greatest in a narrow corridor where
winds are backed to southerly near the MCV and near the warm front
where low-level vorticity should be enhanced.
..Bentley/Hart.. 06/20/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...IWX...IND...LOT...ILX...
LAT...LON 39828860 40048872 40738869 41348849 41618788 41638701
41768622 41718552 41488527 40798527 40108660 40048723
39728838 39828860SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 10:57 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, Champaign, Cook and 39 more | 2 hr |
| Jun 20, 4:01 PM CDT | Severe Thunderstorm Watch | SPC | Hancock, Henderson, Mercer, Rock Island | 7 hr |
| Jun 20, 6:56 PM CDT | Mesoscale Discussion | SPC | Adams, Hancock, Henderson | 2 hr |
| Jun 19, 7:14 PM CDT | Mesoscale Discussion | SPC | Adams, Allen, Blackford, Carroll, Cass, Clinton and 30 more | 91 min |
| Jun 19, 7:50 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Allen, Cass, DeKalb, Elkhart, Fulton and 14 more | 3 hr |
| Jun 20, 5:06 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Allen, Blackford, Boone, Carroll, Cass and 38 more | 7 hr |
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.