Alert archive / Arkansas / Mesoscale Discussions in 2018

Mesoscale Discussion 247

April 13, 2018Garland County, Howard County, Pike County, Arkansas

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2018, 8:36 PM CDT for Garland County, Howard County, Pike County, Arkansas. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Apr 13, 2018, 8:36 PM CDT (01:36 UTC)
Expired: Apr 13, 2018, 9:30 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center

Counties Garland County, AR, Howard County, AR, Pike County, AR

The radar

The Western Arkansas radar (KSRX), 131 km from the middle of the area, began a volume at 01:37 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 watches that followed

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

Tornado Watch 45Apr 13, 9:50 PM CDT

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 1.6 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-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: 1539 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 1018 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 238 m²/s²
0-3 km storm-relative helicity: 235 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 13.1

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
Apr 13, 7:06 PM CDT	Mesoscale Discussion	SPC	Howard, Montgomery, Yell	24 min
Apr 13, 7:22 PM CDT	Tornado Watch	SPC	Arkansas, Ashley, Chicot, Desha, Drew, Lincoln and 1 more	3 hr
Apr 13, 8:54 PM CDT	Mesoscale Discussion	SPC	Arkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 47 more	66 min
Apr 13, 9:53 PM CDT	Tornado Watch	SPC	Arkansas, Baxter, Bradley, Calhoun, Clark, Cleburne and 37 more	8 hr
Apr 13, 10:12 PM CDT	Tornado Watch	SPC	Ashley, Chicot, Clay, Craighead, Crittenden, Cross and 8 more	10 hr
Apr 14, 2:10 AM CDT	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Desha, Drew and 3 more	2 hr

Nearby

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.