Alert archive / South Dakota / Mesoscale Discussions in 2004
Mesoscale Discussion 369
The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2004, 12:42 PM MDT for 16 counties in Nebraska; 26 counties in South Dakota. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 18, 2004, 12:42 PM MDT (18:42 UTC)
- Expired
- Apr 18, 2004, 3:15 PM MDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
All 42 counties
Arthur County, NE, Blaine County, NE, Boyd County, NE, Brown County, NE, Cherry County, NE, Grant County, NE, Holt County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Rock County, NE, Sheridan County, NE, Thomas County, NE, Aurora County, SD, Beadle County, SD, Bennett County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Davison County, SD, Dewey County, SD, Douglas County, SD, Faulk County, SD, Gregory County, SD, Haakon 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, Potter County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD
The radar
The North Platte radar (KLNX), 155 km from the middle of the area, began a volume at 18:46 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 12:00Z, 6.7 hours before the alert went out and 228 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
- 5 J/kg
- Mixed-layer CIN
- -600 J/kg
- Mixed-layer LCL
- 648 m above ground
- 0-6 km bulk shear
- 75 kt
- 0-1 km storm-relative helicity
- 257 m²/s²
- 0-3 km storm-relative helicity
- 268 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -7.6
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 18, 1:20 PM MDT | Severe Thunderstorm Watch | SPC | Antelope, Boyd, Cedar, Dixon, Garfield, Holt and 8 more | 6 hr |
| Apr 18, 3:40 PM MDT | Tornado Watch | SPC | Adams, Burt, Butler, Cass, Clay, Colfax and 29 more | 5 hr |
| Apr 18, 4:23 PM MDT | Mesoscale Discussion | SPC | Antelope, Boyd, Cedar, Dixon, Garfield, Holt and 8 more | 2 hr |
| Apr 17, 10:10 PM MDT | Mesoscale Discussion | SPC | Brookings, Clay, Codington, Deuel, Grant, Hamlin and 10 more | 95 min |
| Apr 17, 10:35 PM MDT | Severe Thunderstorm Watch | SPC | Bon Homme, Brookings, Codington, Deuel, Grant, Hamlin and 12 more | 5 hr |
| Apr 18, 1:37 AM MDT | Mesoscale Discussion | SPC | Brookings, Codington, Deuel, Grant, Hamlin, Kingsbury and 3 more | 53 min |
| Apr 18, 3:43 AM MDT | Mesoscale Discussion | SPC | Roberts | 32 min |
Nearby
Mesoscale Discussions in South Dakota, 2004Mesoscale Discussions in Nebraska, 2004Every 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.