Alert archive / Arkansas / Mesoscale Discussions in 2015

Mesoscale Discussion 684

May 17, 201517 counties in Arkansas; 12 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 17, 2015, 4:27 AM CDT for 17 counties in Arkansas; 12 counties in Missouri. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: May 17, 2015, 4:27 AM CDT (09:27 UTC)
Expired: May 17, 2015, 6:00 AM CDT
In force: 93 min
Issued by: the Storm Prediction Center

All 29 counties

Baxter County, AR, Cleburne County, AR, Conway County, AR, Faulkner County, AR, Fulton County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Pope County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Carter County, MO, Crawford County, MO, Dent County, MO, Howell County, MO, Iron County, MO, Oregon County, MO, Phelps County, MO, Reynolds County, MO, Ripley County, MO, Shannon County, MO, Texas County, MO, Washington County, MO

The radar

The Springfield radar (KSGF), 155 km from the middle of the area, began a volume at 09:31 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, 9.5 hours before the alert went out and 177 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: 1727 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 1056 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 218 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 11.8

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
May 16, 8:42 PM CDT	Tornado Watch	SPC	Benton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more	8 hr
May 17, 1:43 AM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Carroll, Cleburne, Conway, Crawford and 18 more	92 min
May 17, 2:06 AM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Cleburne, Conway, Fulton, Independence and 10 more	5 hr
May 17, 6:25 AM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Cleburne, Conway, Fulton, Independence and 10 more	65 min
May 16, 8:31 PM CDT	Mesoscale Discussion	SPC	Andrew, Bates, Buchanan, Caldwell, Carroll, Cass and 15 more	89 min
May 16, 10:21 PM CDT	Tornado Watch	SPC	Barry, Barton, Benton, Cedar, Christian, Dade and 11 more	5 hr
May 16, 10:27 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Bates, Caldwell, Carroll, Cass, Chariton and 15 more	4 hr

Nearby

Mesoscale Discussions in Arkansas, 2015 Mesoscale Discussions in Missouri, 2015 Every mesoscale discussion in 2015

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.