Alert archive / South Dakota / Mesoscale Discussions in 2004

Mesoscale Discussion 2009

August 15, 20045 counties in Nebraska; 17 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 15, 2004, 12:43 PM MDT for 5 counties in Nebraska; 17 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 15, 2004, 12:43 PM MDT (18:43 UTC)
Expired: Aug 15, 2004, 2:45 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 22 counties

Box Butte County, NE, Cherry County, NE, Dawes County, NE, Sheridan County, NE, Sioux County, NE, Beadle County, SD, Bennett County, SD, Brule County, SD, Buffalo County, SD, Clark County, SD, Faulk County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Spink County, SD, Todd County, SD, Tripp County, SD

The radar

The Rapid City radar (KUDX), 171 km from the middle of the area, began a volume at 18:47 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 754Aug 15, 1:50 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 6.7 hours before the alert went out and 173 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: 4 J/kg
Mixed-layer CIN: -203 J/kg
Mixed-layer LCL: 2064 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 50 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
Aug 15, 1:50 PM MDT	Severe Thunderstorm Watch	SPC	Arthur, Cherry, Deuel, Garden, Grant, Hooker and 2 more	6 hr
Aug 15, 4:01 PM MDT	Mesoscale Discussion	SPC	Boyd, Cherry, Grant, Keya Paha, Knox, Sheridan	119 min

Nearby

Mesoscale Discussions in South Dakota, 2004 Mesoscale Discussions in Nebraska, 2004 Every mesoscale discussion in 2004

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.