Alert archive / Indiana / Mesoscale Discussions in 2021

Mesoscale Discussion 1101

June 25, 2021Iroquois County, Kankakee County, Vermilion County, Illinois; 28 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2021, 7:05 PM CDT for Iroquois County, Kankakee County, Vermilion County, Illinois; 28 counties in Indiana. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Jun 25, 2021, 7:05 PM CDT (00:05 UTC)
Expired: Jun 25, 2021, 8:00 PM CDT
In force: 55 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 319

All 31 counties

Iroquois County, IL, Kankakee County, IL, Vermilion County, IL, Benton County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Elkhart County, IN, Fountain County, IN, Fulton County, IN, Howard County, IN, Jasper County, IN, Kosciusko County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Parke County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Wabash County, IN, Warren County, IN, White County, IN

The radar

The Northern Indiana radar (KIWX), 94 km from the middle of the area, began a volume at 00:07 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

Lincoln, IL (KILX), launched 00:00Z, 0.1 hours before the alert went out and 185 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1254 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 910 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 204 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 6.6

Open this sounding in Storm Lab

The text

As transmitted.

252 
ACUS11 KWNS 260005
SWOMCD
SPC MCD 260005 
INZ000-ILZ000-260100-

Mesoscale Discussion 1101
NWS Storm Prediction Center Norman OK
0705 PM CDT Fri Jun 25 2021

Areas affected...northwest Indiana

Concerning...Severe Thunderstorm Watch 319...

Valid 260005Z - 260100Z

The severe weather threat for Severe Thunderstorm Watch 319
continues.

SUMMARY...Thunderstorms will continue to develop northeastward out
of central Illinois into northwest Indiana this evening. Marginally
severe hail, gusty winds, and a brief tornado will be possible.

DISCUSSION...Thunderstorms are expected to continue developing
northeastward this evening. Surface dewpoints in the low 70s and
temperatures in the low 80s will maintain most-unstable CAPE values
up to 1000 J/kg. This should be maintained into the evening as the
low-level jet develops this evening and maintains low-level theta-e.
This should support at least a marginally severe hail threat and
potential for strong thunderstorm outflow. Additionally, a myriad of
outflow boundaries from earlier convection remain across the area.
Any thunderstorm updraft that latches onto one of these boundaries
may result in a brief tornado.

..Marsh.. 06/26/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...IWX...IND...LOT...ILX...

LAT...LON   39598701 39598703 39608753 40998825 41108825 41208824
            41718752 41718752 41758682 41758613 41758604 41758566
            41588566 41488565 40918564 40858564 40658564 40418586
            39598701 39598701

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 25, 8:34 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calhoun, Cass, Champaign, Christian and 30 more	86 min
Jun 25, 10:31 PM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Cass, Champaign, Christian, Coles and 30 more	59 min
Jun 26, 11:45 AM CDT	Mesoscale Discussion	SPC	Calhoun, Cass, Champaign, Christian, DeWitt, Ford and 21 more	2 hr
Jun 26, 12:05 PM CDT	Tornado Watch	SPC	Cass, Champaign, Christian, Coles, Cook, Cumberland and 24 more	9 hr
Jun 26, 2:47 PM CDT	Mesoscale Discussion	SPC	Calhoun, DeWitt, Ford, Greene, Iroquois, Jersey and 8 more	118 min
Jun 26, 6:08 PM CDT	Mesoscale Discussion	SPC	Champaign, Coles, Cumberland, Douglas, Edgar, Ford and 5 more	67 min
Jun 26, 12:48 PM CDT	Mesoscale Discussion	SPC	LaPorte, Saint Joseph	57 min
Jun 26, 6:47 PM CDT	Severe Thunderstorm Watch	SPC	Carroll, Clinton, Fountain, Montgomery, Parke, Tippecanoe and 2 more	3 hr

Nearby

Mesoscale Discussions in Indiana, 2021 Mesoscale Discussions in Illinois, 2021 Every 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.