Alert archive / South Dakota / Mesoscale Discussions in 2012
Mesoscale Discussion 1249
The Storm Prediction Center issued this mesoscale discussion at Jun 22, 2012, 11:43 PM CDT for 9 counties in Nebraska; 14 counties in South Dakota; Weston County, Wyoming. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- Jun 22, 2012, 11:43 PM CDT (04:43 UTC)
- Expired
- Jun 23, 2012, 1:15 AM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
All 24 counties
Blaine County, NE, Boyd County, NE, Brown County, NE, Cherry County, NE, Garfield County, NE, Holt County, NE, Keya Paha County, NE, Loup County, NE, Rock County, NE, Bennett County, SD, Butte County, SD, Custer County, SD, Gregory County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Todd County, SD, Tripp County, SD, Weston County, WY
The radar
The Rapid City radar (KUDX), 134 km from the middle of the area, began a volume at 04:44 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 nearest sounding before it
Rapid City, SD (KUNR), launched 00:00Z, 4.7 hours before the alert went out and 134 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
- 2140 J/kg
- Mixed-layer CIN
- -85 J/kg
- Mixed-layer LCL
- 2194 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 21 m²/s²
- 0-3 km storm-relative helicity
- 112 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 4.8
The text
As transmitted, in the capitals the NWS used until 2016.
417
ACUS11 KWNS 230443
SWOMCD
SPC MCD 230443
NEZ000-SDZ000-WYZ000-230615-
MESOSCALE DISCUSSION 1249
NWS STORM PREDICTION CENTER NORMAN OK
1143 PM CDT FRI JUN 22 2012
AREAS AFFECTED...FAR NORTHEAST WY TO WESTERN/SOUTHERN SD AND
NORTHERN NEB
CONCERNING...SEVERE THUNDERSTORM WATCH 419...420...
VALID 230443Z - 230615Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
419...420...CONTINUES.
SUMMARY...SEVERE TSTM WATCH 420 CONTINUES UNTIL 07Z. DUAL MCS/S WILL
CONTINUE TO POSE AT LEAST AN ISOLATED/MARGINAL SEVERE WIND/HAIL
THREAT INTO THE OVERNIGHT ACROSS WESTERN/SOUTHERN SD INTO
NORTH-CENTRAL NEB. WHILE NOT CURRENTLY ANTICIPATED...A SEVERE TSTM
WATCH ISSUANCE CANNOT BE RULED OUT ACROSS ADDITIONAL PORTIONS OF
SOUTHERN SD INTO NORTH-CENTRAL NEB PENDING DEVELOPMENTAL TRENDS.
DISCUSSION...TWO MCS/S ARE ONGOING AS OF 0430Z WITHIN SEVERE TSTM
WATCH 420. ONE IS NEAR THE BLACK HILLS/I-90 VICINITY NEARING RAPID
CITY...AND THIS SHOULD CONTINUE TO POSE AT LEAST SOME SEVERE THREAT
OVER THE NEXT 1-2 HR AS IT PROPAGATES GENERALLY EASTWARD WITHIN A
RESIDUALLY UNSTABLE AXIS ACROSS WESTERN SD /EVEN IN THE WAKE OF
EARLIER STORMS/. ANOTHER MCS IS CONTINUING TO SPREAD
EAST-SOUTHEASTWARD NEAR THE SD/NEB VICINITY NORTHWEST OF VALENTINE
NEB AS OF 0430Z. WHILE SUSTENANCE OF THIS MCS DOES SEEM LIKELY
ACROSS SOUTHERN SD/NORTH-CENTRAL NEB ON THE NOSE OF A NOCTURNALLY
ENHANCED LOW LEVEL JET /AND WITH POTENTIAL AID OF AN MCV/...DETAILED
MCS EVOLUTION/INTENSITY ARE UNCERTAIN GIVEN FACTORS SUCH AS A DRIER
AIRMASS ACROSS CENTRAL NEB AND THE EXISTING MCS ACROSS SOUTHERN NEB.
..GUYER.. 06/23/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FSD...OAX...ABR...LBF...UNR...CYS...
LAT...LON 45190377 44230061 43309907 42719829 42059852 41579957
42430195 43830469 44360392 45190377SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 22, 7:52 PM CDT | Mesoscale Discussion | SPC | Arthur, Banner, Box Butte, Chase, Cheyenne, Deuel and 9 more | 83 min |
| Jun 22, 9:36 PM CDT | Mesoscale Discussion | SPC | Cherry, Dawes, Sheridan | 84 min |
| Jun 22, 11:03 PM CDT | Mesoscale Discussion | SPC | Arthur, Blaine, Brown, Chase, Cherry, Custer and 14 more | 87 min |
| Jun 23, 1:18 AM CDT | Mesoscale Discussion | SPC | Adams, Antelope, Blaine, Boone, Boyd, Brown and 65 more | 87 min |
Nearby
Mesoscale Discussions in South Dakota, 2012Mesoscale Discussions in Nebraska, 2012Mesoscale Discussions in Wyoming, 2012Every mesoscale discussion in 2012
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.