Alert archive / South Dakota / Mesoscale Discussions in 2013
Mesoscale Discussion 817
The Storm Prediction Center issued this mesoscale discussion at May 27, 2013, 11:36 AM MDT for 4 states. It was in force for 54 min.
The area
The outline as issued.
The facts
- Issued
- May 27, 2013, 11:36 AM MDT (17:36 UTC)
- Expired
- May 27, 2013, 12:30 PM MDT
- In force
- 54 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 25 counties
Carter County, MT, Adams County, ND, Bowman County, ND, Hettinger County, ND, Slope County, ND, Bennett County, SD, Butte County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Ziebach County, SD, Crook County, WY, Weston County, WY
The radar
The Rapid City radar (KUDX), 72 km from the middle of the area, began a volume at 17:37 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
Rapid City, SD (KUNR), launched 12:00Z, 5.6 hours before the alert went out and 79 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
- 832 J/kg
- Mixed-layer CIN
- -71 J/kg
- Mixed-layer LCL
- 578 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 33 m²/s²
- 0-3 km storm-relative helicity
- 147 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 5.2
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 |
|---|---|---|---|---|
| May 26, 6:08 PM MDT | Mesoscale Discussion | SPC | Big Horn, Custer, Fergus, Garfield, Musselshell, Petroleum and 4 more | 2 hr |
| May 26, 9:31 PM MDT | Mesoscale Discussion | SPC | Big Horn, Carter, Custer, McCone, Powder River, Prairie and 2 more | 119 min |
| May 27, 11:51 AM MDT | Severe Thunderstorm Watch | SPC | Big Horn, Carter, Custer, Fallon, Powder River, Rosebud and 1 more | 10 hr |
| May 27, 3:52 PM MDT | Mesoscale Discussion | SPC | Carter, Custer, Fallon, Powder River, Prairie, Wibaux | 83 min |
Nearby
Mesoscale Discussions in South Dakota, 2013Mesoscale Discussions in North Dakota, 2013Mesoscale Discussions in Wyoming, 2013Every mesoscale discussion in 2013
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.