Alert archive / Illinois / Mesoscale Discussions in 2021

Mesoscale Discussion 2005

December 10, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 11:28 PM CST for 4 states. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Dec 10, 2021, 11:28 PM CST (05:28 UTC)
Expired
Dec 11, 2021, 1:00 AM CST
In force
92 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 557...559
All 48 counties

Alexander County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Marion County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Clay County, IN, Daviess County, IN, Fountain County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Owen County, IN, Parke County, IN, Pike County, IN, Posey County, IN, Putnam County, IN, Sullivan County, IN, Vanderburgh County, IN, Vermillion County, IN, Vigo County, IN, Union County, KY, Bollinger County, MO, Cape Girardeau County, MO

The radar

The Evansville,IN radar (KVWX), 50 km from the middle of the area, began a volume at 05:29 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, 5.5 hours before the alert went out and 180 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 00:00Z on 2021-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 119 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2021-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 341 square meters per square second.1939587897Sfc1 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
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

Open this sounding in Storm Lab

The text

As transmitted.

993 
ACUS11 KWNS 110528
SWOMCD
SPC MCD 110528 
INZ000-KYZ000-ILZ000-MOZ000-110700-

Mesoscale Discussion 2005
NWS Storm Prediction Center Norman OK
1128 PM CST Fri Dec 10 2021

Areas affected...far southeast Missouri into east-central Illinois

Concerning...Tornado Watch 557...559...

Valid 110528Z - 110700Z

The severe weather threat for Tornado Watch 557, 559 continues.

SUMMARY...The severe threat continues across Tornado Watches 557 and
559. Large hail and damaging gusts remain the main threats, though a
tornado or two is possible, especially with the storms approaching
eastern Illinois.

DISCUSSION...A line of semi-discrete storms (including supercells)
continues across western portions of Tornado Watches 557 and 559.
Despite several preceding storms earlier in the day, strong
low-level warm-air advection in advance of a 992 mb surface low has
maintained modest buoyancy ahead of the ongoing line of storms, with
mid to upper 60s F temperatures and mid 60s F dewpoints supporting
up to 1000 J/kg MLCAPE and minimal convective inhibition. As such,
large hail and damaging gusts may accompany the stronger storms over
the next few hours. Despite veering low-level winds, strong speed
shear is contributing to 300+ m2/s2 effective SRH, so a tornado or
two also remains possible.

..Squitieri/Grams.. 12/11/2021

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

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

LAT...LON   37309005 38548920 39218866 39938799 40168732 40048696
            39628666 38888681 38218735 37728767 37388813 37108902
            37309005

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 10, 7:02 PM CSTMesoscale DiscussionSPCCalhoun, Greene, Jersey, Macoupin, Madison, Monroe and 4 more58 min
Dec 10, 7:18 PM CSTMesoscale DiscussionSPCChampaign, Christian, Clark, Clay, Coles, Crawford and 18 more87 min
Dec 10, 7:47 PM CSTTornado WatchSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 21 more8 hr
Dec 10, 8:53 PM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Coles and 21 more97 min
Dec 10, 9:36 PM CSTMesoscale DiscussionSPCClark, Coles, Cumberland, Edgar, Effingham, Shelby54 min
Dec 10, 10:09 PM CSTMesoscale DiscussionSPCMassac96 min
Dec 10, 11:03 PM CSTTornado WatchSPCAlexander, Clinton, Edwards, Fayette, Franklin, Gallatin and 17 more5 hr
Dec 10, 6:21 PM CSTTornado WatchSPCClark, Crawford, Dubois, Floyd, Harrison, Jefferson and 4 more10 hr
Dec 10, 8:35 PM CSTMesoscale DiscussionSPCHarrison85 min
Dec 10, 10:25 PM CSTMesoscale DiscussionSPCBartholomew, Benton, Blackford, Boone, Brown, Carroll and 50 more95 min
Dec 10, 11:08 PM CSTMesoscale DiscussionSPCDearborn, Decatur, Delaware, Fayette, Franklin, Hamilton and 16 more67 min
Dec 10, 11:20 PM CSTTornado WatchSPCAdams, Allen, Blackford, Carroll, Cass, Dearborn and 27 more6 hr
Dec 11, 1:46 AM CSTMesoscale DiscussionSPCBartholomew, Brown, Daviess, Dearborn, Decatur, Delaware and 21 more59 min
Dec 10, 6:22 PM CSTMesoscale DiscussionSPCFulton, Graves, Hickman53 min
Dec 10, 7:41 PM CSTMesoscale DiscussionSPCFulton64 min
Dec 10, 8:48 PM CSTMesoscale DiscussionSPCCarlisle, Fulton, Graves, Hickman, Lyon, Marshall57 min
Dec 10, 9:48 PM CSTMesoscale DiscussionSPCCaldwell, Graves, Hopkins, Lyon, Marshall57 min
Dec 10, 10:44 PM CSTMesoscale DiscussionSPCCaldwell, Grayson, Hopkins, McLean, Muhlenberg, Ohio61 min
Dec 10, 11:36 PM CSTMesoscale DiscussionSPCCalloway, Christian, Logan, Simpson, Todd, Trigg54 min
Dec 10, 11:53 PM CSTMesoscale DiscussionSPCBreckinridge, Bullitt, Grayson, Hardin, Jefferson, Meade and 3 more67 min
Dec 11, 1:02 AM CSTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more88 min
Dec 11, 1:05 AM CSTMesoscale DiscussionSPCBarren, Butler, Edmonson, Green, Hart, Logan and 2 more55 min
Dec 11, 1:27 AM CSTTornado WatchSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more7 hr
Dec 11, 2:51 AM CSTMesoscale DiscussionSPCBoyle, Casey, Clark, Estill, Garrard, Jessamine and 4 more54 min
Dec 11, 5:32 AM CSTMesoscale DiscussionSPCBell, Breathitt, Clark, Clay, Estill, Jackson and 18 more88 min
Dec 10, 7:54 PM CSTMesoscale DiscussionSPCChristian, Crawford, Dallas, Dent, Douglas, Greene and 10 more2 hr
Dec 10, 9:40 PM CSTMesoscale DiscussionSPCDunklin, Pemiscot2 hr

Nearby

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