Alert archive / Nebraska / Mesoscale Discussions in 2007

Mesoscale Discussion 1786

August 17, 20075 counties in Colorado; 20 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2007, 7:34 PM MDT for 5 counties in Colorado; 20 counties in Nebraska. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Aug 17, 2007, 7:34 PM MDT (01:34 UTC)
Expired: Aug 17, 2007, 9:30 PM MDT
In force: 116 min
Issued by: the Storm Prediction Center

All 25 counties

Logan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Arthur County, NE, Box Butte County, NE, Chase County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Hayes County, NE, Hooker County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Sheridan County, NE, Thomas County, NE

The radar

The Goodland radar (KGLD), 163 km from the middle of the area, began a volume at 01:36 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

Rapid City, SD (KUNR), launched 00:00Z, 1.6 hours before the alert went out and 371 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: 426 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 1724 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 203 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.7

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
Aug 18, 5:17 PM MDT	Tornado Watch	SPC	Boyd, Brown, Cedar, Dakota, Dixon, Holt and 3 more	6 hr

Nearby

Mesoscale Discussions in Nebraska, 2007 Mesoscale Discussions in Colorado, 2007 Every mesoscale discussion in 2007

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.