Alert archive / South Dakota / Mesoscale Discussions in 2018
Mesoscale Discussion 1074
The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2018, 1:39 PM CDT for 5 counties in Nebraska; 18 counties in South Dakota. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 18, 2018, 1:39 PM CDT (18:39 UTC)
- Expired
- Jul 18, 2018, 3:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 95%
All 23 counties
Boyd County, NE, Brown County, NE, Holt County, NE, Keya Paha County, NE, Rock County, NE, Aurora County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Haakon County, SD, Hughes County, SD, Jackson County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD, Ziebach County, SD
The radar
The North Platte radar (KLNX), 197 km from the middle of the area, began a volume at 18:43 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 204 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1815 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- -90 m²/s²
- 0-3 km storm-relative helicity
- -9 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 11:04 PM CDT | Mesoscale Discussion | SPC | Box Butte, Dawes, Scotts Bluff, Sheridan, Sioux | 86 min |
| Jul 18, 1:57 AM CDT | Mesoscale Discussion | SPC | Arthur, Garden, Grant, Hooker, Keith, McPherson and 2 more | 2 hr |
| Jul 18, 3:43 PM CDT | Tornado Watch | SPC | Antelope, Boyd, Brown, Cedar, Garfield, Holt and 5 more | 7 hr |
| Jul 18, 4:59 PM CDT | Mesoscale Discussion | SPC | Blaine, Brown, Buffalo, Cherry, Custer, Dawson and 15 more | 91 min |
| Jul 18, 5:16 PM CDT | Mesoscale Discussion | SPC | Antelope, Boyd, Cedar, Dixon, Holt, Keya Paha and 5 more | 119 min |
| Jul 18, 6:14 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Antelope, Blaine, Boone, Boyd, Brown and 52 more | 7 hr |
Nearby
Mesoscale Discussions in South Dakota, 2018Mesoscale Discussions in Nebraska, 2018Every mesoscale discussion in 2018
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.