Alert archive / South Dakota / Mesoscale Discussions in 2011
Mesoscale Discussion 705
The Storm Prediction Center issued this mesoscale discussion at May 9, 2011, 4:57 PM MDT for 5 counties in Nebraska; 6 counties in South Dakota; 6 counties in Wyoming. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- May 9, 2011, 4:57 PM MDT (22:57 UTC)
- Expired
- May 9, 2011, 6:30 PM MDT
- In force
- 93 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 22:58 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, 11.0 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
- 90 J/kg
- Mixed-layer CIN
- -588 J/kg
- Mixed-layer LCL
- 782 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 95 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
192 ACUS11 KWNS 092257 SWOMCD SPC MCD 092257 SDZ000-NEZ000-WYZ000-100030- MESOSCALE DISCUSSION 0705 NWS STORM PREDICTION CENTER NORMAN OK 0557 PM CDT MON MAY 09 2011 AREAS AFFECTED...ERN WY...NWRN NEB...SWRN SD CONCERNING...SEVERE THUNDERSTORM WATCH 266... VALID 092257Z - 100030Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 266 CONTINUES. LEADING EDGE OF STRONGER FORCING APPEARS TO BE SPREADING ACROSS THE CNTRL ROCKIES INTO THE NRN/CNTRL HIGH PLAINS REGION. THIS CORRESPONDS WELL WITH ONGOING BAND OF CONVECTION THAT HAS TRAVERSED THE LARAMIE RANGE OF WY. THIS ACTIVITY SHOULD GRADUALLY INCREASE IN AREAL COVERAGE/INTENSITY AS IT ENCOUNTERS FAVORABLE INFLOW WITHIN UPSLOPE FLOW REGIME INVOF THE BLACK HILLS. LARGE HAIL IS THE PRIMARY SEVERE CONCERN WITH THIS EVOLVING LINE OF TSTMS...WHILE NEW DEVELOPMENT MAY ALSO OCCUR WITHIN WARM ADVECTION AHEAD OF THESE STORMS. ..DARROW.. 05/09/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LBF...UNR...CYS... LAT...LON 41650582 44830505 44830199 41640292 41650582
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 7:47 PM MDT | Mesoscale Discussion | SPC | Antelope, Boone, Boyd, Brown, Garfield, Holt and 4 more | 58 min |
| May 9, 2:26 PM MDT | Severe Thunderstorm Watch | SPC | Box Butte, Dawes, Scotts Bluff, Sheridan, Sioux | 7 hr |
| May 9, 1:17 PM MDT | Mesoscale Discussion | SPC | Campbell, Converse, Crook, Fremont, Hot Springs, Johnson and 4 more | 58 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.