Alert archive / Arkansas / Mesoscale Discussions in 2017

Mesoscale Discussion 435

April 4, 201715 counties in Arkansas; 13 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2017, 11:38 PM CDT for 15 counties in Arkansas; 13 counties in Missouri. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Apr 4, 2017, 11:38 PM CDT (04:38 UTC)
Expired: Apr 5, 2017, 1:15 AM CDT
In force: 97 min
Issued by: the Storm Prediction Center

All 28 counties

Baxter County, AR, Cleburne County, AR, Conway County, AR, Faulkner County, AR, Fulton County, AR, Garland County, AR, Izard County, AR, Montgomery County, AR, Perry County, AR, Pope County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Yell County, AR, Carter County, MO, Crawford County, MO, Dent County, MO, Howell County, MO, Iron County, MO, Madison County, MO, Oregon County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Shannon County, MO, Washington County, MO, Wayne County, MO

The radar

The Springfield radar (KSGF), 140 km from the middle of the area, began a volume at 04:37 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, 4.6 hours before the alert went out and 162 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: 326 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 1384 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 312 m²/s²
0-3 km storm-relative helicity: 743 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 12.5

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
Apr 4, 9:12 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Conway, Fulton, Garland, Hempstead and 19 more	4 hr
Apr 4, 9:28 PM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Carroll, Clark, Cleburne, Conway and 32 more	92 min
Apr 4, 7:40 PM CDT	Mesoscale Discussion	SPC	Barry, Christian, Greene, Lawrence, Stone	65 min

Nearby

Mesoscale Discussions in Arkansas, 2017 Mesoscale Discussions in Missouri, 2017 Every 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.