Alert archive / Arkansas / Mesoscale Discussions in 2013

Mesoscale Discussion 169

February 18, 201313 counties in Arkansas

The Storm Prediction Center issued this mesoscale discussion at Feb 18, 2013, 4:54 PM CST for 13 counties in Arkansas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Feb 18, 2013, 4:54 PM CST (22:54 UTC)
Expired: Feb 18, 2013, 6:00 PM CST
In force: 66 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Arkansas County, AR, Desha County, AR, Drew County, AR, Independence County, AR, Jackson County, AR, Jefferson County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Phillips County, AR, Prairie County, AR, White County, AR, Woodruff County, AR

The radar

The Little Rock radar (KLZK), 78 km from the middle of the area, began a volume at 22:54 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

Shreveport, LA (KSHV), launched 12:00Z, 10.9 hours before the alert went out and 311 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 668 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 510 m²/s²
0-3 km storm-relative helicity: 670 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 18, 1:29 PM CST	Mesoscale Discussion	SPC	Clark, Columbia, Crawford, Franklin, Garland, Hempstead and 14 more	2 hr
Feb 18, 2:19 PM CST	Severe Thunderstorm Watch	SPC	Arkansas, Bradley, Calhoun, Carroll, Clark, Cleveland and 42 more	7 hr
Feb 18, 3:52 PM CST	Mesoscale Discussion	SPC	Calhoun, Clark, Columbia, Conway, Dallas, Garland and 15 more	83 min
Feb 18, 5:59 PM CST	Mesoscale Discussion	SPC	Bradley, Calhoun, Cleveland, Columbia, Dallas, Jefferson and 5 more	91 min

Nearby

Mesoscale Discussions in Arkansas, 2013 Every mesoscale discussion in 2013

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.