Alert archive / Illinois / Mesoscale Discussions in 2021

Mesoscale Discussion 772

May 27, 202120 counties in Illinois; 9 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 27, 2021, 3:38 PM CDT for 20 counties in Illinois; 9 counties in Missouri. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
May 27, 2021, 3:38 PM CDT (20:38 UTC)
Expired
May 27, 2021, 4:45 PM CDT
In force
67 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 214
All 29 counties

Clay County, IL, Crawford County, IL, Edwards County, IL, Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Lawrence County, IL, Marion County, IL, Perry County, IL, Randolph County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Bollinger County, MO, Cape Girardeau County, MO, Carter County, MO, Madison County, MO, Oregon County, MO, Perry County, MO, Reynolds County, MO, Sainte Genevieve County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 119 km from the middle of the area, began a volume at 20:37 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 12:00Z, 8.6 hours before the alert went out and 268 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, Lincoln, IL at 12:00Z on 2021-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2021-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1679 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

699 
ACUS11 KWNS 272038
SWOMCD
SPC MCD 272038 
INZ000-ILZ000-MOZ000-272145-

Mesoscale Discussion 0772
NWS Storm Prediction Center Norman OK
0338 PM CDT Thu May 27 2021

Areas affected...parts of southern Illinois and southeastern
Missouri

Concerning...Severe Thunderstorm Watch 214...

Valid 272038Z - 272145Z

The severe weather threat for Severe Thunderstorm Watch 214
continues.

SUMMARY...Local risk for damaging winds continues with stronger
storms within the convective band across WW 214.

DISCUSSION...Latest radar shows active storms continuing within a
northeast-to-southwest band extending from southeastern Illinois
into far southern Missouri.  Ahead of the band -- from southeastern
Missouri to southern Illinois, ample instability suggests that
storms will continue shifting eastward as a well-organized line, at
around 35 kt.  Stronger storms/segments within the broader line
remain capable of producing locally gusty/damaging winds over the
next couple of hours.

..Goss.. 05/27/2021

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

ATTN...WFO...IND...PAH...ILX...LSX...SGF...

LAT...LON   36619174 36989152 37469089 38388979 38738876 39088836
            39158765 38818747 37938804 36969012 36619174

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 27, 11:04 AM CDTMesoscale DiscussionSPCBond, Calhoun, Christian, Clinton, Coles, Effingham and 18 more86 min
May 27, 11:26 AM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Cass, Champaign, Christian, Clark and 42 more8 hr
May 27, 12:57 PM CDTMesoscale DiscussionSPCBond, Christian, Clinton, Effingham, Fayette, Jersey and 12 more93 min
May 27, 2:20 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clay, Clinton, Effingham, Fayette and 16 more85 min
May 27, 5:21 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hamilton, Hardin, Johnson, Massac and 6 more114 min
May 27, 12:51 AM CDTMesoscale DiscussionSPCBarton, Buchanan, Platte84 min
May 27, 1:05 AM CDTSevere Thunderstorm WatchSPCBates, Buchanan, Cass, Clay, Jackson, Platte and 1 more7 hr
May 27, 5:28 AM CDTMesoscale DiscussionSPCCass, Jackson92 min
May 27, 1:36 PM CDTMesoscale DiscussionSPCAndrew, Buchanan, Cass, Clay, Clinton, DeKalb and 2 more54 min
May 27, 2:06 PM CDTMesoscale DiscussionSPCButler, Dunklin, Oregon, Ripley84 min
May 27, 6:03 PM CDTMesoscale DiscussionSPCAdair, Audrain, Boone, Buchanan, Caldwell, Carroll and 27 more87 min

Nearby

Mesoscale Discussions in Illinois, 2021Mesoscale Discussions in Missouri, 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.