Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 1984
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 5:27 PM CST for Calhoun County, Jersey County, Illinois; 30 counties in Missouri. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 5:27 PM CST (23:27 UTC)
- Expired
- Dec 10, 2021, 8:30 PM CST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 553
All 32 counties
Calhoun County, IL, Jersey County, IL, Audrain County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Dallas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Hickory County, MO, Laclede County, MO, Lincoln County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Webster County, MO, Wright County, MO
The radar
The St Louis radar (KLSX), 128 km from the middle of the area, began a volume at 23:31 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
Springfield, MO (KSGF), launched 12:00Z, 11.5 hours before the alert went out and 213 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.
- Mixed-layer CAPE
- 62 J/kg
- Mixed-layer CIN
- -145 J/kg
- Mixed-layer LCL
- 870 m above ground
- 0-6 km bulk shear
- 67 kt
- 0-1 km storm-relative helicity
- 419 m²/s²
- 0-3 km storm-relative helicity
- 441 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.2
The text
As transmitted.
666
ACUS11 KWNS 102328
SWOMCD
SPC MCD 102327
ILZ000-MOZ000-110230-
Mesoscale Discussion 1984
NWS Storm Prediction Center Norman OK
0527 PM CST Fri Dec 10 2021
Areas affected...Portions of southwest into east-central Missouri
Concerning...Tornado Watch 553...
Valid 102327Z - 110230Z
The severe weather threat for Tornado Watch 553 continues.
SUMMARY...The severe threat appears to be gradually increasing
across portions of central Missouri. Large hail and damaging wind
gusts appear to be the primary threats, though a few tornadoes are
also likely, especially across eastern Missouri later this evening.
DISCUSSION...Deep-moist convection has recently initiated across
portions of southwest MO, just northwest of SGF within the past
hour. These storms are developing along the western fringes of a
moist warm sector, where near 60 F surface dewpoints are overspread
by 7 C/km mid-level lapse rates (evident via 22Z mesoanalysis and
previously noted by the 19Z SGF observed sounding). While the
surface winds are somewhat veered, the 21Z SGF VWP showed a modestly
curved but long hodograph depicting well over 300 m2/s2 SRH in both
the 0-1 km and 0-3 km layers.
As deep-layer ascent increases across the area and convective
inhibition continues to wane, additional storms are expected to
develop over the next several hours. A mixed mode of linear segments
and semi-discrete storms are expected, with all severe hazards
(including a couple of tornadoes) likely. The best chance for
tornadoes will be later this evening across eastern MO as the more
mature storms progress farther east into the LLJ axis, where
low-level shear is expected to be strongest and where MLCAPE may
exceed 1000 J/kg.
..Squitieri/Grams.. 12/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...SGF...EAX...
LAT...LON 37409190 37119260 37079314 37229368 37739385 38629335
39359194 39469106 39249044 38939021 38509047 38009114
37409190SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 1:35 PM CST | Mesoscale Discussion | SPC | Alexander, Pulaski, Union | 2 hr |
| Dec 10, 3:07 PM CST | Tornado Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more | 11 hr |
| Dec 10, 4:45 PM CST | Mesoscale Discussion | SPC | Alexander, Hardin, Jackson, Johnson, Massac, Pope and 3 more | 90 min |
| Dec 10, 5:17 PM CST | Tornado Watch | SPC | Adams, Bond, Brown, Calhoun, Cass, Christian and 18 more | 6 hr |
| Dec 10, 2:44 PM CST | Mesoscale Discussion | SPC | Audrain, Boone, Carroll, Chariton, Clark, Cooper and 13 more | 2 hr |
Nearby
Mesoscale Discussions in Missouri, 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.