Alert archive / South Dakota / Mesoscale Discussions in 2016

Mesoscale Discussion 853

June 9, 2016Carter County, Powder River County, Montana; 13 counties in South Dakota; 4 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jun 9, 2016, 4:06 PM MDT for Carter County, Powder River County, Montana; 13 counties in South Dakota; 4 counties in Wyoming. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jun 9, 2016, 4:06 PM MDT (22:06 UTC)
Expired: Jun 9, 2016, 5:30 PM MDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Carter County, MT, Powder River County, MT, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD, Campbell County, WY, Crook County, WY, Johnson County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 125 km from the middle of the area, began a volume at 22:09 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.

Severe Thunderstorm Watch 240Jun 9, 6:45 PM MDT

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 10.1 hours before the alert went out and 123 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: 31 J/kg
Mixed-layer CIN: -307 J/kg
Mixed-layer LCL: 2224 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

226 
ACUS11 KWNS 092207
SWOMCD
SPC MCD 092206 
SDZ000-MTZ000-WYZ000-092330-

MESOSCALE DISCUSSION 0853
NWS STORM PREDICTION CENTER NORMAN OK
0506 PM CDT THU JUN 09 2016

AREAS AFFECTED...PORTIONS OF SERN MT...NERN WY...AND WRN SD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 092206Z - 092330Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THUNDERSTORMS DEVELOPING/MOVING ACROSS THIS REGION MAY
POSE AN ISOLATED SEVERE RISK THROUGH THE EVENING...WITH LARGE HAIL
AND DAMAGING WINDS THE MAIN THREATS. WW ISSUANCE IS UNLIKELY AT THE
MOMENT DUE TO THE ISOLATED THREAT.

DISCUSSION...ISOLATED CONVECTION HAS RECENTLY INITIATED OVER THE
BLACK HILLS OF WRN SD...AND ADDITIONAL CONVECTION MAY DEVELOP ACROSS
NERN WY INTO SERN MT OVER THE NEXT HOUR OR TWO IN ASSOCIATION WITH
THE GLANCING INFLUENCE OF AN UPPER TROUGH OVER THE ERN PACIFIC. THIS
ACTIVITY WILL LIE ON THE FRINGE OF STRONGER MID-LEVEL FLOW PRESENT
OVER MUCH OF CNTRL INTO ERN MT. LATEST VWP FROM KUDX INDICATES A
VERTICALLY VEERING WIND PROFILE THROUGH 6 KM...BUT WINDS AT/BELOW 4
KM ARE GENERALLY 15 KT OR LESS. STILL...0-6 KM SHEAR AROUND 30-35 KT
SHOULD ALLOW FOR SOME STORM ORGANIZATION...MAINLY MULTICELLS POSING
AN ISOLATED LARGE HAIL/DAMAGING WIND RISK. SFC OBSERVATIONS ACROSS
MOST OF THE MCD AREA REVEAL LIMITED LOW-LEVEL MOISTURE...WITH
DEWPOINTS GENERALLY IN THE MID 40S AND LOWER 50S. STILL...WITH VERY
STEEP LOW TO MID-LEVEL LAPSE RATES PRESENT...MLCAPE AROUND 250-1250
J/KG WILL BE SUFFICIENT TO SUPPORT CONVECTIVE DEVELOPMENT. AN ARCING
BAND OF BROKEN CONVECTION POSING MAINLY A LOCALLY DAMAGING WIND
THREAT ACROSS N-CNTRL WY MAY MOVE INTO WRN PORTIONS OF THE MCD AREA
OVER THE NEXT SEVERAL HOURS IF IT IS ABLE TO MAINTAIN ITSELF.
REGARDLESS...THE LIMITED LOW-LEVEL MOISTURE AND MARGINAL SHEAR
SHOULD KEEP THE SEVERE THREAT ISOLATED ACROSS THIS REGION.

..GLEASON/CORFIDI.. 06/09/2016

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

ATTN...WFO...ABR...UNR...CYS...BYZ...RIW...

LAT...LON   43910662 44980665 45710520 45900396 45890197 45010147
            43010158 43010400 43250526 43910662

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 9, 11:44 AM MDT	Mesoscale Discussion	SPC	Broadwater, Fergus, Garfield, Golden Valley, Judith Basin, McCone and 4 more	3 hr
Jun 9, 1:01 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Cascade, Chouteau, Custer, Daniels and 26 more	9 hr
Jun 9, 1:48 PM MDT	Mesoscale Discussion	SPC	Fergus, Garfield, Judith Basin, McCone, Petroleum	57 min
Jun 9, 2:51 PM MDT	Mesoscale Discussion	SPC	Blaine, Custer, Daniels, Dawson, Fergus, Gallatin and 19 more	84 min
Jun 9, 2:18 PM MDT	Mesoscale Discussion	SPC	Big Horn, Campbell, Converse, Fremont, Hot Springs, Johnson and 3 more	2 hr

Nearby

Mesoscale Discussions in South Dakota, 2016 Mesoscale Discussions in Wyoming, 2016 Mesoscale Discussions in Montana, 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.