Alert archive / Missouri / Mesoscale Discussions in 2018

Mesoscale Discussion 1105

July 20, 20188 counties in Arkansas; 11 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2018, 3:46 PM CDT for 8 counties in Arkansas; 11 counties in Missouri. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Jul 20, 2018, 3:46 PM CDT (20:46 UTC)
Expired: Jul 20, 2018, 4:45 PM CDT
In force: 59 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

Counties Baxter County, AR, Boone County, AR, Fulton County, AR, Izard County, AR, Marion County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Carter County, MO, Christian County, MO, Douglas County, MO, Howell County, MO, Oregon County, MO, Ozark County, MO, Ripley County, MO, Shannon County, MO, Taney County, MO, Texas County, MO, Wright County, MO

The radar

The Springfield radar (KSGF), 107 km from the middle of the area, began a volume at 20:50 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 293Jul 20, 4:00 PM CDT

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 8.8 hours before the alert went out and 128 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1151 J/kg
Mixed-layer CIN: -259 J/kg
Mixed-layer LCL: 1847 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 197 m²/s²
0-3 km storm-relative helicity: 203 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 19, 7:07 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Carroll, Cleburne, Fulton, Independence and 10 more	3 hr
Jul 19, 8:02 PM CDT	Mesoscale Discussion	SPC	Arkansas, Baxter, Clark, Cleburne, Cleveland, Conway and 40 more	118 min
Jul 19, 8:54 PM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Clay, Cleveland and 35 more	114 min
Jul 19, 11:21 PM CDT	Mesoscale Discussion	SPC	Chicot, Desha, Phillips	114 min
Jul 20, 9:25 AM CDT	Mesoscale Discussion	SPC	Arkansas, Cleburne, Crittenden, Cross, Faulkner, Independence and 13 more	2 hr
Jul 20, 12:58 PM CDT	Mesoscale Discussion	SPC	Clay	62 min
Jul 20, 3:58 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Clay, Craighead, Cross, Fulton, Greene and 8 more	6 hr
Jul 20, 5:54 PM CDT	Mesoscale Discussion	SPC	Crittenden, Lee, Phillips, St. Francis	3 hr
Jul 20, 6:22 PM CDT	Tornado Watch	SPC	Crittenden, Lee, Mississippi, Phillips, St. Francis	8 hr
Jul 19, 9:36 PM CDT	Mesoscale Discussion	SPC	Clark, Knox, Lewis, Lincoln, Marion, Pike and 3 more	54 min

Nearby

Mesoscale Discussions in Missouri, 2018 Mesoscale Discussions in Arkansas, 2018 Every mesoscale discussion in 2018

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.