Alert archive / South Dakota / Mesoscale Discussions in 2011
Mesoscale Discussion 706
The Storm Prediction Center issued this mesoscale discussion at May 9, 2011, 8:16 PM MDT for 5 counties in Nebraska; 6 counties in South Dakota; 6 counties in Wyoming. It was in force for 29 min.
The area
The outline as issued.
The facts
- Issued
- May 9, 2011, 8:16 PM MDT (02:16 UTC)
- Expired
- May 9, 2011, 8:45 PM MDT
- In force
- 29 min
- Issued by
- the Storm Prediction Center
Counties Box Butte County, NE, Dawes County, NE, Morrill County, NE, Scotts Bluff County, NE, Sioux County, NE, Custer County, SD, Fall River County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Albany County, WY, Crook County, WY, Goshen County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY
The radar
The Rapid City radar (KUDX), 180 km from the middle of the area, began a volume at 02:17 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 00:00Z, 2.3 hours before the alert went out and 173 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
- 231 J/kg
- Mixed-layer CIN
- -129 J/kg
- Mixed-layer LCL
- 581 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 114 m²/s²
- 0-3 km storm-relative helicity
- 247 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
767 ACUS11 KWNS 100216 SWOMCD SPC MCD 100216 SDZ000-NEZ000-WYZ000-100245- MESOSCALE DISCUSSION 0706 NWS STORM PREDICTION CENTER NORMAN OK 0916 PM CDT MON MAY 09 2011 AREAS AFFECTED...ERN WY...NWRN NEB...SWRN SD CONCERNING...SEVERE THUNDERSTORM WATCH 266... VALID 100216Z - 100245Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 266 CONTINUES. ...NEW SEVERE THUNDERSTORM WATCH WILL LIKELY BE REQUIRED BY 03Z... THUNDERSTORMS HAVE GRADUALLY INCREASED IN AREAL COVERAGE ACROSS WRN SD INTO THE NRN NEB PANHANDLE. THIS ACTIVITY SHOULD LINGER WELL INTO THE OVERNIGHT HOURS AS WARM ADVECTION REMAINS FOCUSED BENEATH A LLJ BRANCH TO THE NORTH OF EJECTING SFC LOW. DEEP LAYER VERTICAL SHEAR REMAINS SUPPORTIVE OF SUPERCELLS AND CURRENT THINKING IS THE SEVERE THREAT...ESPECIALLY HAIL...WILL CONTINUE PAST WATCH EXPIRATION. A NEW WW IS WARRANTED TO ACCOUNT FOR THIS ONGOING ACTIVITY. ..DARROW.. 05/10/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LBF...UNR...CYS... LAT...LON 41640582 44830504 44830199 41650291 41640582
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 8:34 PM MDT | Severe Thunderstorm Watch | SPC | Sheridan | 5 hr |
| May 9, 10:17 PM MDT | Mesoscale Discussion | SPC | Cherry | 58 min |
| May 10, 12:56 AM MDT | Mesoscale Discussion | SPC | Butte, Corson, Dewey, Meade, Perkins, Stanley and 1 more | 94 min |
Nearby
Mesoscale Discussions in South Dakota, 2011Mesoscale Discussions in Wyoming, 2011Mesoscale Discussions in Nebraska, 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.