Alert archive / Nebraska / Mesoscale Discussions in 2003

Mesoscale Discussion 1911

July 20, 2003Sedgwick County, Colorado; 19 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2003, 12:25 PM MDT for Sedgwick County, Colorado; 19 counties in Nebraska. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jul 20, 2003, 12:25 PM MDT (18:25 UTC)
Expired: Jul 20, 2003, 2:00 PM MDT
In force: 95 min
Issued by: the Storm Prediction Center

Counties Sedgwick County, CO, Arthur County, NE, Blaine County, NE, Brown County, NE, Chase County, NE, Cheyenne County, NE, Custer County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Thomas County, NE

The radar

The North Platte radar (KLNX), 91 km from the middle of the area, began a volume at 18:26 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.

Severe Thunderstorm Watch 775Jul 20, 3:50 PM MDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 6.4 hours before the alert went out and 101 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: 3043 J/kg
Mixed-layer CIN: -132 J/kg
Mixed-layer LCL: 1067 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 27 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.1

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
Jul 20, 3:32 PM MDT	Mesoscale Discussion	SPC	Logan, Phillips, Sedgwick, Yuma	58 min
Jul 20, 1:09 PM MDT	Mesoscale Discussion	SPC	Antelope, Burt, Butler, Cedar, Colfax, Cuming and 14 more	66 min
Jul 20, 1:50 PM MDT	Tornado Watch	SPC	Burt, Cass, Cedar, Colfax, Cuming, Dakota and 13 more	6 hr
Jul 20, 3:50 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Boone, Buffalo, Butler, Chase, Clay and 35 more	4 hr
Jul 20, 4:29 PM MDT	Mesoscale Discussion	SPC	Burt, Cass, Colfax, Cuming, Dakota, Dodge and 11 more	91 min

Nearby

Mesoscale Discussions in Nebraska, 2003 Mesoscale Discussions in Colorado, 2003 Every mesoscale discussion in 2003

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.