Alert archive / Indiana / Mesoscale Discussions in 2021
Mesoscale Discussion 2002
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 11:25 PM EST for 56 counties in Indiana. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 11:25 PM EST (04:25 UTC)
- Expired
- Dec 11, 2021, 1:00 AM EST
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 557
All 56 counties
Bartholomew County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, Decatur County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Franklin County, IN, Fulton County, IN, Grant County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jackson County, IN, Jasper County, IN, Jay County, IN, Jennings County, IN, Johnson County, IN, Kosciusko County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Marshall County, IN, Miami County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Pulaski County, IN, Putnam County, IN, Randolph County, IN, Ripley County, IN, Rush County, IN, Shelby County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Wabash County, IN, Warren County, IN, Wayne County, IN, Wells County, IN, White County, IN, Whitley County, IN
The radar
The Indianapolis radar (KIND), 70 km from the middle of the area, began a volume at 04:27 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, 4.4 hours before the alert went out and 209 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.
060
ACUS11 KWNS 110426
SWOMCD
SPC MCD 110425
INZ000-ILZ000-110600-
Mesoscale Discussion 2002
NWS Storm Prediction Center Norman OK
1025 PM CST Fri Dec 10 2021
Areas affected...much of Indiana
Concerning...Tornado Watch 557...
Valid 110425Z - 110600Z
The severe weather threat for Tornado Watch 557 continues.
SUMMARY...The severe threat continues across Tornado Watch 557, and
may progress eastward across much of Indiana. Damaging gusts are
expected to be the main threat across northern into central Indiana,
with a couple of brief tornadoes possible across southern Indiana.
An additional Tornado Watch issuance may be needed in southern
Indiana.
DISCUSSION...A broken line of storms, including occasional embedded
supercells, persists across central and eastern parts of Tornado
Watch 557. Mainly strong/damaging gusts have been observed over the
past couple of hours, though a TDS (suggesting the presence of a
tornado) has recently been noted in Coles, County IL. Across
Indiana, a near saturated low-level airmass is in place, with
surface observations showing both temperatures and dewpoints in the
mid to upper 50s F in northern/central IN, with lower 60s F
temperatures/dewpoints observed in southern IN.
Given the modest low-level temperatures and mid-level lapse rates,
buoyancy is currently poor across IN, with modest convective
inhibition in place. Since low-level airmass recovery is not
expected to be overly robust across northern/central IN,
near-surface based storms may support occasional strong to damaging
wind gusts. A relatively greater threat for damaging gusts and
perhaps a couple of tornadoes may develop farther south in southern
IN where the richer low-level moisture is in place. A downstream
Tornado Watch may be needed in southern IN.
..Squitieri/Grams.. 12/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ILN...LMK...IWX...IND...LOT...ILX...
LAT...LON 38688735 40058754 40978735 41338701 41438673 41488650
41518625 41508576 41368548 40878502 40438490 39958495
39318502 38978516 38788608 38688735SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 7:21 PM EST | Tornado Watch | SPC | Clark, Crawford, Dubois, Floyd, Harrison, Jefferson and 4 more | 10 hr |
| Dec 10, 8:18 PM EST | Mesoscale Discussion | SPC | Bartholomew, Benton, Boone, Brown, Carroll, Cass and 37 more | 87 min |
| Dec 10, 8:47 PM EST | Tornado Watch | SPC | Bartholomew, Benton, Boone, Brown, Clay, Clinton and 24 more | 8 hr |
| Dec 10, 9:35 PM EST | Mesoscale Discussion | SPC | Harrison | 85 min |
| Dec 10, 10:36 PM EST | Mesoscale Discussion | SPC | Vigo | 54 min |
| Dec 11, 12:03 AM EST | Tornado Watch | SPC | Gibson, Pike, Posey, Spencer, Vanderburgh, Warrick | 5 hr |
| Dec 11, 12:08 AM EST | Mesoscale Discussion | SPC | Dearborn, Decatur, Delaware, Fayette, Franklin, Hamilton and 16 more | 67 min |
| Dec 11, 12:20 AM EST | Tornado Watch | SPC | Adams, Allen, Blackford, Carroll, Cass, Dearborn and 27 more | 6 hr |
| Dec 11, 12:28 AM EST | Mesoscale Discussion | SPC | Clay, Daviess, Fountain, Gibson, Greene, Knox and 9 more | 92 min |
| Dec 11, 2:46 AM EST | Mesoscale Discussion | SPC | Bartholomew, Brown, Daviess, Dearborn, Decatur, Delaware and 21 more | 59 min |
Nearby
Mesoscale Discussions in Indiana, 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.