Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1861

August 4, 2011Logan County, Sedgwick County, Colorado; 11 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2011, 7:17 PM MDT for Logan County, Sedgwick County, Colorado; 11 counties in Nebraska. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Aug 4, 2011, 7:17 PM MDT (01:17 UTC)
Expired
Aug 4, 2011, 8:15 PM MDT
In force
58 min
Issued by
the Storm Prediction Center

Counties Logan County, CO, Sedgwick County, CO, Arthur County, NE, Cherry County, NE, Cheyenne County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, McPherson County, NE, Morrill County, NE, Thomas County, NE

The radar

The North Platte radar (KLNX), 141 km from the middle of the area, began a volume at 01:21 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

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.3 hours before the alert went out and 145 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-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2011-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1463 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 00:00Z on 2011-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1463 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
1429 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
-5 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.

IssuedProductOfficeCountiesLasted
Aug 5, 4:25 PM MDTMesoscale DiscussionSPCBanner, Box Butte, Dawes, Kimball, Morrill, Scotts Bluff and 2 more2 hr

Nearby

Mesoscale Discussions in Nebraska, 2011Mesoscale Discussions in Colorado, 2011Every mesoscale discussion in 2011

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.