Alert archive / South Dakota / Mesoscale Discussions in 2012
Mesoscale Discussion 1304
The Storm Prediction Center issued this mesoscale discussion at Jun 29, 2012, 7:59 AM CDT for 4 states. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Jun 29, 2012, 7:59 AM CDT (12:59 UTC)
- Expired
- Jun 29, 2012, 9:30 AM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 54 counties
Lyon County, IA, Plymouth County, IA, Sioux County, IA, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Boyd County, NE, Cedar County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Clark County, SD, Clay County, SD, Codington County, SD, Davison County, SD, Deuel County, SD, Dewey County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hutchinson County, SD, Hyde County, SD, Jerauld County, SD, Jones County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, Lyman County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Potter County, SD, Sanborn County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Tripp County, SD, Turner County, SD, Union County, SD, Walworth County, SD, Yankton County, SD
The radar
The Aberdeen radar (KABR), 118 km from the middle of the area, began a volume at 13:03 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
Aberdeen, SD (KABR), launched 12:00Z, 1.0 hours before the alert went out and 64 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
- 444 J/kg
- Mixed-layer CIN
- -507 J/kg
- Mixed-layer LCL
- 1747 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 116 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
938
ACUS11 KWNS 291300
SWOMCD
SPC MCD 291259
MNZ000-IAZ000-NEZ000-SDZ000-291430-
MESOSCALE DISCUSSION 1304
NWS STORM PREDICTION CENTER NORMAN OK
0759 AM CDT FRI JUN 29 2012
AREAS AFFECTED...SD TO NORTHEAST NEB/SOUTHWEST MN/NORTHWEST IA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 291259Z - 291430Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...SEVERE POTENTIAL MAY INCREASE THIS MORNING...INITIALLY IN
THE FORM OF SEVERE HAIL AND EVENTUALLY DAMAGING WINDS. CONVECTIVE
TRENDS BEING MONITORED FOR A POSSIBLE WATCH.
DISCUSSION...A CLUSTER OF TSTMS HAVE QUICKLY INTENSIFIED THIS
MORNING ACROSS NORTH-CENTRAL SD THIS MORNING...WHILE OTHER MORE
ISOLATED WARM-ADVECTION AIDED TSTMS HAVE INCREASED ALONG THE SD/NEB
BORDER. THIS DEVELOPMENT APPEARS TO BE READILY TIED TO A SHORTWAVE
TROUGH MOVING EASTWARD INTO THE WESTERN DAKOTAS...AND THIS FEATURE
WILL LARGELY COINCIDE WITH A RELATIVELY MOIST AIRMASS ASSOCIATED
WITH A WNW-ESE EXTENDING SURFACE FRONT ACROSS THE LOWER MO RIVER
VALLEY. IT SEEMS LIKELY THAT STRONG/POTENTIALLY SEVERE TSTMS WILL
CONTINUE TO INCREASE/SPREAD EASTWARD THIS MORNING. SEVERE HAIL WILL
BE POSSIBLE WITH THE STRONGEST UPDRAFTS WITHIN A STRONGLY
SHEARED/STEEP LAPSE RATE ENVIRONMENT...ALTHOUGH DAMAGING WINDS COULD
BECOME MORE OF A CONCERN AS STORMS CONGEAL AND THE BOUNDARY LAYER
DESTABILIZES.
..GUYER/MEAD.. 06/29/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MPX...FSD...OAX...ABR...LBF...UNR...
LAT...LON 45190132 45640012 45399770 44229514 42449641 43080030
45190132SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 29, 2:43 PM CDT | Mesoscale Discussion | SPC | Adair, Appanoose, Benton, Black Hawk, Boone, Buchanan and 31 more | 3 hr |
| Jun 29, 3:49 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Cedar, Clinton, Des Moines, Henry, Iowa and 19 more | 5 hr |
| Jun 29, 5:04 PM CDT | Mesoscale Discussion | SPC | Iowa, Johnson, Poweshiek | 26 min |
| Jun 29, 5:35 PM CDT | Mesoscale Discussion | SPC | Dickinson, Lyon, Osceola | 55 min |
| Jun 28, 10:24 PM CDT | Mesoscale Discussion | SPC | Adams, Boone, Buffalo, Clay, Custer, Dawson and 32 more | 66 min |
Nearby
Mesoscale Discussions in South Dakota, 2012Mesoscale Discussions in Minnesota, 2012Mesoscale Discussions in Iowa, 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.