Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 6

January 1, 202110 counties in Illinois; 17 counties in Kansas; 55 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jan 1, 2021, 2:33 AM CST for 10 counties in Illinois; 17 counties in Kansas; 55 counties in Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jan 1, 2021, 2:33 AM CST (08:33 UTC)
Expired
Jan 1, 2021, 7:30 AM CST
In force
5 hr
Issued by
the Storm Prediction Center
Concerning
Freezing rain
All 82 counties

Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Greene County, IL, Jersey County, IL, Morgan County, IL, Pike County, IL, Schuyler County, IL, Scott County, IL, Allen County, KS, Anderson County, KS, Bourbon County, KS, Coffey County, KS, Crawford County, KS, Douglas County, KS, Franklin County, KS, Johnson County, KS, Leavenworth County, KS, Linn County, KS, Lyon County, KS, Miami County, KS, Neosho County, KS, Osage County, KS, Wilson County, KS, Woodson County, KS, Wyandotte County, KS, Audrain County, MO, Barton County, MO, Bates County, MO, Benton County, MO, Boone County, MO, Caldwell County, MO, Callaway County, MO, Camden County, MO, Carroll County, MO, Cass County, MO, Cedar County, MO, Chariton County, MO, Clay County, MO, Cole County, MO, Cooper County, MO, Dade County, MO, Dallas County, MO, Franklin County, MO, Gasconade County, MO, Henry County, MO, Hickory County, MO, Howard County, MO, Jackson County, MO, Jasper County, MO, Johnson County, MO, Knox County, MO, Laclede County, MO, Lafayette County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Pike County, MO, Platte County, MO, Polk County, MO, Pulaski County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Saint Charles County, MO, Saline County, MO, Shelby County, MO, St. Clair County, MO, Vernon County, MO, Warren County, MO

The radar

The Pleasant Hill radar (KEAX), 73 km from the middle of the area, began a volume at 08:38 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

Topeka, KS (KTOP), launched 00:00Z, 8.6 hours before the alert went out and 194 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, Topeka, KS at 00:00Z on 2021-01-01Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Topeka, KS at 00:00Z on 2021-01-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1791 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

078 
ACUS11 KWNS 010834
SWOMCD
SPC MCD 010833 
ILZ000-MOZ000-KSZ000-011330-

Mesoscale Discussion 0006
NWS Storm Prediction Center Norman OK
0233 AM CST Fri Jan 01 2021

Areas affected...eastern KS...central/northern MO...west-central IL

Concerning...Freezing rain 

Valid 010833Z - 011330Z

SUMMARY...Moderate to heavy freezing rain is expected to shift
northward across eastern KS into central/northern MO and
west-central IL through the early morning hours.

DISCUSSION...Moderate to heavy freezing rain has been noted recently
across southeast KS toward the I-44 corridor in southwest and
central MO. Freezing rain rates have been as high as 0.05 in/hr in
these locations. A more pronounced/stronger deformation region has
developed northward toward the I-70 corridor from eastern KS into
central MO as the upper low continues to shift northward from north
Texas into southern OK, and is evident in water vapor loops over the
past hour. As midlevel moistening continues, freezing rain will
develop northward and increase in intensity through early morning.
Forecast soundings suggest precipitation type should predominantly
be freezing rain. However, some sleet or snow could mix in at times
as modest midlevel cooling occurs on the back side of the mid/upper
low, resulting in a deepening isothermal layer around 900-750 mb.
Once freezing rain begins, rates greater than 0.05 inches per 3
hours are expected for several hours.

..Leitman.. 01/01/2021

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

ATTN...WFO...ILX...LSX...DVN...SGF...EAX...TOP...ICT...

LAT...LON   38299632 38719617 39179535 39379493 39859363 40269171
            40329089 40209034 39958996 39638990 38829040 38279114
            37739213 37269334 37159455 37329560 37629611 37989626
            38299632

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 1, 1:08 AM CSTMesoscale DiscussionSPCBond, Brown, Calhoun, Cass, Champaign, Christian and 43 more5 hr
Jan 1, 6:35 AM CSTMesoscale DiscussionSPCAdams, Brown, Bureau, Cass, Champaign, DeWitt and 34 more4 hr
Dec 31, 8:44 PM CSTMesoscale DiscussionSPCCherokee, Crawford6 hr

Nearby

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