Alert archive / Indiana / Mesoscale Discussions in 2021

Mesoscale Discussion 1043

June 20, 202120 counties in Indiana; 17 counties in Michigan; 13 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2021, 11:51 PM EDT for 20 counties in Indiana; 17 counties in Michigan; 13 counties in Ohio. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Jun 20, 2021, 11:51 PM EDT (03:51 UTC)
Expired
Jun 21, 2021, 12:45 AM EDT
In force
54 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 295
All 50 counties

Adams County, IN, Allen County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Huntington County, IN, Kosciusko County, IN, LaGrange County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, Whitley County, IN, Allegan County, MI, Barry County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Livingston County, MI, Monroe County, MI, Saint Joseph County, MI, Van Buren County, MI, Washtenaw County, MI, Wayne County, MI, Defiance County, OH, Fulton County, OH, Hancock County, OH, Henry County, OH, Lucas County, OH, Ottawa County, OH, Paulding County, OH, Putnam County, OH, Sandusky County, OH, Seneca County, OH, Van Wert County, OH, Williams County, OH, Wood County, OH

The radar

The Northern Indiana radar (KIWX), 89 km from the middle of the area, began a volume at 03:52 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

Detroit, MI (KDTX), launched 00:00Z, 3.9 hours before the alert went out and 154 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-pSkew-T log-p diagram, Detroit, MI at 00:00Z on 2021-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 133 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 00:00Z on 2021-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
133 J/kg
Mixed-layer CIN
-112 J/kg
Mixed-layer LCL
1501 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

505 
ACUS11 KWNS 210351
SWOMCD
SPC MCD 210351 
OHZ000-MIZ000-INZ000-210445-

Mesoscale Discussion 1043
NWS Storm Prediction Center Norman OK
1051 PM CDT Sun Jun 20 2021

Areas affected...Northern IN...northwest OH...southern Lower
Michigan

Concerning...Severe Thunderstorm Watch 295...

Valid 210351Z - 210445Z

The severe weather threat for Severe Thunderstorm Watch 295
continues.

SUMMARY...A new Severe Thunderstorm Watch will likely be needed
before the 05z expiration of WW 295 for upstream thunderstorms
posing a severe risk into the overnight hours.

DISCUSSION...Evening surface analysis shows a composite warm
front/outflow boundary near the IN/OH/MI border, with a recent
increase in strong/isolated severe thunderstorms in the vicinity of
the front.  A strengthening low-level jet will focus warm/moist
advection in the vicinity of the front during the early overnight
hours, providing a feed of unstable air into the region as
strong/severe thunderstorms currently over northeast IL continue to
move east.  Current indications, supported by recent high-res
guidance, are for a continued severe threat beyond the scheduled 05z
expiration of ww 295.  This will necessitate coordination of a new
watch prior to that time.

..Bunting.. 06/21/2021

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

ATTN...WFO...CLE...ILN...DTX...IWX...GRR...

LAT...LON   42938610 42858466 42798367 42388314 41858296 41338284
            40988300 40768436 40558540 40628614 41008686 41788671
            42938610

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 8:14 PM EDTMesoscale DiscussionSPCAdams, Allen, Blackford, Boone, Carroll, Cass and 30 more61 min
Jun 20, 10:40 PM EDTSevere Thunderstorm WatchSPCBenton, Jasper, Lake, Newton, Porter4 hr
Jun 21, 1:00 AM EDTSevere Thunderstorm WatchSPCAllen, DeKalb, Elkhart, Fulton, Kosciusko, LaGrange and 8 more7 hr
Jun 21, 2:14 AM EDTMesoscale DiscussionSPCAllen, DeKalb, Elkhart, Fulton, Kosciusko, LaGrange and 8 more2 hr
Jun 21, 11:59 AM EDTMesoscale DiscussionSPCAshland, Ashtabula, Athens, Belmont, Carroll, Columbiana and 31 more91 min
Jun 21, 12:31 PM EDTSevere Thunderstorm WatchSPCAdams, Ashtabula, Athens, Belmont, Carroll, Columbiana and 33 more7 hr

Nearby

Mesoscale Discussions in Indiana, 2021Mesoscale Discussions in Michigan, 2021Mesoscale Discussions in Ohio, 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.