Alert archive / Missouri / Mesoscale Discussions in 2017

Mesoscale Discussion 1782

December 4, 2017Adams County, Brown County, Pike County, Illinois; 28 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Dec 4, 2017, 6:05 PM CST for Adams County, Brown County, Pike County, Illinois; 28 counties in Missouri. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Dec 4, 2017, 6:05 PM CST (00:05 UTC)
Expired
Dec 4, 2017, 8:00 PM CST
In force
115 min
Issued by
the Storm Prediction Center
All 31 counties

Adams County, IL, Brown County, IL, Pike County, IL, Audrain County, MO, Barry County, MO, Callaway County, MO, Camden County, MO, Christian County, MO, Cole County, MO, Dallas County, MO, Douglas County, MO, Gasconade County, MO, Greene County, MO, Laclede County, MO, Lincoln County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Montgomery County, MO, Osage County, MO, Ozark County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Ralls County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Webster County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 117 km from the middle of the area, began a volume at 00:04 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 00:00Z, 0.1 hours before the alert went out and 226 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 00:00Z on 2017-12-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 507 joules per kilogram.LCLLFCEL10008507005003002001001 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, Springfield, MO at 00:00Z on 2017-12-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 342 square meters per square second.1939587897117Sfc1 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
507 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
845 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
342 m²/s²
0-3 km storm-relative helicity
415 m²/s²
Significant tornado parameter
1.1
Supercell composite
4.5

Open this sounding in Storm Lab

The text

As transmitted.

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Nearby

Mesoscale Discussions in Missouri, 2017Mesoscale Discussions in Illinois, 2017Every mesoscale discussion in 2017

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.