Alert archive / South Dakota / Mesoscale Discussions in 2016

Mesoscale Discussion 972

June 17, 20164 counties in Iowa; 7 counties in Nebraska; 8 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 17, 2016, 8:57 PM CDT for 4 counties in Iowa; 7 counties in Nebraska; 8 counties in South Dakota. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Jun 17, 2016, 8:57 PM CDT (01:57 UTC)
Expired: Jun 17, 2016, 10:00 PM CDT
In force: 63 min
Issued by: the Storm Prediction Center

Counties Cherokee County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Cedar County, NE, Dakota County, NE, Dixon County, NE, Knox County, NE, Pierce County, NE, Thurston County, NE, Wayne County, NE, Bon Homme County, SD, Clay County, SD, Hanson County, SD, Hutchinson County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 74 km from the middle of the area, began a volume at 02:00 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

Omaha, NE (KOAX), launched 00:00Z, 2.0 hours before the alert went out and 185 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3543 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 1690 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 90 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

552 
ACUS11 KWNS 180158
SWOMCD
SPC MCD 180157 
IAZ000-NEZ000-SDZ000-180300-

MESOSCALE DISCUSSION 0972
NWS STORM PREDICTION CENTER NORMAN OK
0857 PM CDT FRI JUN 17 2016

AREAS AFFECTED...SERN SD...NWRN IA AND NERN NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 267...

VALID 180157Z - 180300Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 267
CONTINUES.

SUMMARY...STORMS ARE EXPECTED TO CONTINUE TO POSE A THREAT FOR
DAMAGING WIND GUSTS AS THEY CONTINUE SWWD THROUGH SERN SD...NWRN IA
AND INTO NE NEB THIS EVENING. AN ADDITIONAL WW MIGHT BE NEEDED SOUTH
OF WW 267 TO INCLUDE NERN NEB.

DISCUSSION...CLUSTER OF STRONG TO SEVERE STORMS CONTINUES DEVELOPING
THROUGH SERN SD INTO NWRN IA ALONG A SWWD MOVING OUTFLOW BOUNDARY.
THE DOWNSTREAM ATMOSPHERE ACROSS NERN NEB REMAINS VERY UNSTABLE WITH
AROUND 3500 J/KG MLCAPE AND STEEP LAPSE RATES. CONVECTIVE INHIBITION
WILL SLOWLY INCREASE THE REMAINDER OF THE EVENING. HOWEVER...THIS
PROCESS MIGHT BE SLOW ENOUGH TO ALLOW ADDITIONAL DEVELOPMENT ALONG
SWWD MOVING OUTFLOW BOUNDARY INTO NERN NEB...ESPECIALLY GIVEN THE
STRENGTH OF THE COLD POOL.

..DIAL.. 06/18/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FSD...OAX...

LAT...LON   43809786 43349685 43079585 42889497 42259577 41909685
            42259781 43159833 43809786

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 17, 7:23 PM CDT	Mesoscale Discussion	SPC	Cerro Gordo, Emmet, Hancock, Kossuth, Palo Alto, Winnebago and 1 more	2 hr

Nearby

Mesoscale Discussions in South Dakota, 2016 Mesoscale Discussions in Nebraska, 2016 Mesoscale Discussions in Iowa, 2016 Every mesoscale discussion in 2016

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.