Alert archive / South Dakota / Mesoscale Discussions in 2011
Mesoscale Discussion 701
The Storm Prediction Center issued this mesoscale discussion at May 8, 2011, 5:06 PM CDT for 4 counties in Nebraska; Emmons County, Sioux County, North Dakota; 21 counties in South Dakota. It was in force for 54 min.
The area
The outline as issued.
The facts
- Issued
- May 8, 2011, 5:06 PM CDT (22:06 UTC)
- Expired
- May 8, 2011, 6:00 PM CDT
- In force
- 54 min
- Issued by
- the Storm Prediction Center
All 27 counties
Emmons County, ND, Sioux County, ND, Brown County, NE, Cherry County, NE, Keya Paha County, NE, Rock County, NE, Brule County, SD, Buffalo County, SD, Campbell County, SD, Corson County, SD, Dewey County, SD, Edmunds County, SD, Gregory County, SD, Haakon County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD
The radar
The Rapid City radar (KUDX), 167 km from the middle of the area, began a volume at 22:06 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, 10.1 hours before the alert went out and 171 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
- 1753 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 187 m²/s²
- 0-3 km storm-relative helicity
- 344 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
526 ACUS11 KWNS 082206 SWOMCD SPC MCD 082206 SDZ000-NEZ000-NDZ000-082300- MESOSCALE DISCUSSION 0701 NWS STORM PREDICTION CENTER NORMAN OK 0506 PM CDT SUN MAY 08 2011 AREAS AFFECTED...NCNTRL NEB TO SCNTRL ND CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 082206Z - 082300Z CU FIELD IS GRADUALLY EXPANDING/DEEPENING WITHIN POST DRYLINE ENVIRONMENT ACROSS THE NEB PANHANDLE. THIS CONVECTION IS INDICATIVE OF THE VERY STEEP LAPSE RATES IN PLACE ACROSS THE CNTRL HIGH PLAINS WHERE SFC TEMPERATURES HAVE WARMED INTO THE MID 80S. LATEST THINKING IS SUSTAINED CONVERGENCE ALONG THE DRYLINE SHOULD PROVE FAVORABLE FOR ENCOURAGING SUSTAINED DEEP UPDRAFTS/TSTMS BY 00Z-02Z. GIVEN THE VERY UNSTABLE AIRMASS IN PLACE ANY STORMS THAT DEVELOP WILL LIKELY PRODUCE VERY LARGE HAIL...IN ADDITION TO ISOLATED TORNADOES WITH EARLY SUPERCELL ACTIVITY. ..DARROW.. 05/08/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FSD...ABR...BIS...LBF...UNR... LAT...LON 42480138 44470211 46600135 46039925 42279897 42480138
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 6:13 PM CDT | Tornado Watch | SPC | Antelope, Blaine, Boone, Boyd, Brown, Cherry and 11 more | 6 hr |
Nearby
Mesoscale Discussions in South Dakota, 2011Mesoscale Discussions in Nebraska, 2011Mesoscale Discussions in North Dakota, 2011Every mesoscale discussion in 2011
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.