Alert archive / South Dakota / Mesoscale Discussions in 2007
Mesoscale Discussion 533
The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2007, 8:16 PM CDT for 38 counties in South Dakota. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2007, 8:16 PM CDT (01:16 UTC)
- Expired
- Apr 21, 2007, 10:15 PM CDT
- In force
- 119 min
- Issued by
- the Storm Prediction Center
All 38 counties
Aurora County, SD, Beadle County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Charles Mix County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Day County, SD, Deuel County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jerauld County, SD, Jones County, SD, Kingsbury County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Mellette County, SD, Miner County, SD, Potter County, SD, Roberts County, SD, Sanborn County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD
The radar
The Aberdeen radar (KABR), 124 km from the middle of the area, began a volume at 01:16 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.
The nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 1.3 hours before the alert went out and 66 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.
- Mixed-layer CAPE
- 1323 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 965 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 1 m²/s²
- 0-3 km storm-relative helicity
- 265 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 4.6
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 7:56 PM CDT | Mesoscale Discussion | SPC | Aurora, Beadle, Brown, Brule, Buffalo, Campbell and 32 more | 2 hr |
| Apr 21, 10:34 PM CDT | Severe Thunderstorm Watch | SPC | Aurora, Beadle, Bon Homme, Brookings, Brule, Charles Mix and 15 more | 3 hr |
| Apr 22, 1:56 PM CDT | Tornado Watch | SPC | Bon Homme, Clay, Union, Yankton | 7 hr |
| Apr 22, 5:59 PM CDT | Mesoscale Discussion | SPC | Bon Homme, Clay, Lincoln, Turner, Yankton | 2 hr |
Nearby
Mesoscale Discussions in South Dakota, 2007Every 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.