Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 199

March 17, 2021Calhoun County, Illinois; 41 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 17, 2021, 8:51 AM CDT for Calhoun County, Illinois; 41 counties in Missouri. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Mar 17, 2021, 8:51 AM CDT (13:51 UTC)
Expired
Mar 17, 2021, 10:15 AM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 42 counties

Calhoun County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Christian County, MO, Cole County, MO, Crawford County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Hickory County, MO, Howell County, MO, Iron County, MO, Jefferson 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, Ozark County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Shannon County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Webster County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 138 km from the middle of the area, began a volume at 13:52 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, 1.9 hours before the alert went out and 201 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, Springfield, MO at 12:00Z on 2021-03-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 102 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, Springfield, MO at 12:00Z on 2021-03-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 220 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
102 J/kg
Mixed-layer CIN
-235 J/kg
Mixed-layer LCL
956 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
220 m²/s²
0-3 km storm-relative helicity
236 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

357 
ACUS11 KWNS 171352
SWOMCD
SPC MCD 171351 
ILZ000-MOZ000-171515-

Mesoscale Discussion 0199
NWS Storm Prediction Center Norman OK
0851 AM CDT Wed Mar 17 2021

Areas affected...Portions of central and eastern MIssouri

Concerning...Severe potential...Watch unlikely 

Valid 171351Z - 171515Z

Probability of Watch Issuance...20 percent

SUMMARY...A few storms capable of large hail are possible this
morning.

DISCUSSION...A few elevated storms in central Missouri have recently
reported 1 inch hail. These storms have formed in an airmass with
500-750 MUCAPE per SPC mesoanalysis. These storms are quickly moving
away from the better instability, but an additional storm cluster
across southern Missouri may pose a severe threat as it moves
northeastward. The 12Z KSGF RAOB showed moderate mid-level lapse
rates of 7 to 7.5 C/km and MUCAPE around 1300 J/kg. This, combined
with effective shear around 40 to 45 knots should be sufficient for
a continued threat for a few stronger storms capable of mostly large
hail. The sharp surface inversion evident on the KSGF RAOB will
likely limit the overall damaging wind threat, but a strong gust or
two also cannot be ruled out. A watch is unlikely this morning, but
an additional severe weather threat is still expected later this
afternoon/evening as the surface low approaches.

..Bentley/Grams.. 03/17/2021

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

ATTN...WFO...PAH...LSX...SGF...EAX...

LAT...LON   38809288 39179233 39349179 39399125 39319078 39069040
            38739029 37999039 37449058 37039079 36739142 36639216
            36559262 36569301 36739331 36919371 37229374 38809288

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 17, 12:45 AM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Cass, Cedar, Dade and 8 more90 min
Mar 17, 1:54 AM CDTSevere Thunderstorm WatchSPCBarry, Barton, Bates, Cedar, Dade, Jasper and 5 more6 hr
Mar 17, 5:18 AM CDTMesoscale DiscussionSPCBarton, Bates, Vernon87 min
Mar 17, 1:18 PM CDTMesoscale DiscussionSPCBarry, Jasper, Lawrence, McDonald, Newton, Stone and 1 more57 min
Mar 17, 2:00 PM CDTTornado WatchSPCBarry, Christian, Douglas, Greene, Lawrence, McDonald and 6 more7 hr
Mar 17, 3:37 PM CDTMesoscale DiscussionSPCBarry, Christian, Douglas, Greene, Jasper, Lawrence and 5 more83 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.