Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 641
The Storm Prediction Center issued this mesoscale discussion at May 16, 2021, 5:49 PM CDT for 4 counties in Illinois; 22 counties in Missouri. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- May 16, 2021, 5:49 PM CDT (22:49 UTC)
- Expired
- May 16, 2021, 7:15 PM CDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 26 counties
Calhoun County, IL, Greene County, IL, Jersey County, IL, Pike County, IL, Audrain County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Cole County, MO, Cooper County, MO, Gasconade County, MO, Henry County, MO, Howard County, MO, Johnson County, MO, Lincoln County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 96 km from the middle of the area, began a volume at 22:52 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 nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 10.8 hours before the alert went out and 277 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
- 122 J/kg
- Mixed-layer CIN
- -133 J/kg
- Mixed-layer LCL
- 1041 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 85 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
918 ACUS11 KWNS 162250 SWOMCD SPC MCD 162249 ILZ000-MOZ000-170015- Mesoscale Discussion 0641 NWS Storm Prediction Center Norman OK 0549 PM CDT Sun May 16 2021 Areas affected...Central Missouri and West-Central Illinois Concerning...Severe potential...Watch unlikely Valid 162249Z - 170015Z Probability of Watch Issuance...5 percent SUMMARY...A few storms capable of severe hail and damaging winds possible this evening. DISCUSSION...Regional surface analysis shows a convectively reinforced east-west oriented baroclinic zone/stationary boundary situated along the I-70 corridor across central Missouri. South of this boundary, southerly low-level flow is present, with surface dew point temperatures in the low 60s F and 20-25 kt of flow at 850 mb. These factors are providing the impetus for renewed convective development along and north of the boundary. South of the boundary, the environment features modest indices to support severe convection, including MUCAPE of 1000-1500 J/kg, low-level lapse rates near 7-8 C/km, and effective bulk shear of 30-35 kt. Given these conditions, a few strong storms are possible, posing a threat for severe hail and damaging wind gusts. Current trends suggest this activity should remain fairly isolated, and thus, a watch issuance is not anticipated at this time. ..Karstens/Grams.. 05/16/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILX...LSX...SGF...EAX... LAT...LON 38888996 37999218 38289444 38999350 39849064 38888996
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 16, 1:27 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Boone, Callaway, Camden and 28 more | 93 min |
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.