Alert archive / Montana / Mesoscale Discussions in 2016

Mesoscale Discussion 879

June 11, 201617 counties in Montana; 16 counties in North Dakota; Corson County, Harding County, Perkins County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2016, 7:36 PM MDT for 17 counties in Montana; 16 counties in North Dakota; Corson County, Harding County, Perkins County, South Dakota. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2016, 7:36 PM MDT (01:36 UTC)
Expired
Jun 11, 2016, 9:00 PM MDT
In force
84 min
Issued by
the Storm Prediction Center
All 36 counties

Big Horn County, MT, Carter County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, Garfield County, MT, McCone County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Sheridan County, MT, Treasure County, MT, Valley County, MT, Wibaux County, MT, Adams County, ND, Billings County, ND, Bowman County, ND, Dunn County, ND, Golden Valley County, ND, Grant County, ND, Hettinger County, ND, McKenzie County, ND, Mercer County, ND, Morton County, ND, Mountrail County, ND, Oliver County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Williams County, ND, Corson County, SD, Harding County, SD, Perkins County, SD

The radar

The Glasgow radar (KGGW), 185 km from the middle of the area, began a volume at 01:39 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.6 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-pSkew-T log-p diagram, Glasgow Intl Airport, MT at 00:00Z on 2016-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 727 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Glasgow Intl Airport, MT at 00:00Z on 2016-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 231 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
727 J/kg
Mixed-layer CIN
-201 J/kg
Mixed-layer LCL
1190 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
231 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

056 
ACUS11 KWNS 120136
SWOMCD
SPC MCD 120136 
SDZ000-NDZ000-MTZ000-WYZ000-120300-

MESOSCALE DISCUSSION 0879
NWS STORM PREDICTION CENTER NORMAN OK
0836 PM CDT SAT JUN 11 2016

AREAS AFFECTED...PORTIONS OF ERN MT...WRN ND...NWRN SD...FAR NRN WY

CONCERNING...SEVERE THUNDERSTORM WATCH 246...247...

VALID 120136Z - 120300Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
246...247...CONTINUES.

SUMMARY...SCATTERED SEVERE TSTMS WILL CONTINUE TO SPREAD ACROSS
PORTIONS OF THE NRN HIGH PLAINS THROUGH MID EVENING.

DISCUSSION...MULTIPLE CLUSTERS OF STRONG TO SEVERE TSTMS...SOME WITH
A HISTORY OF PRODUCING HAIL TO 2 INCHES IN DIAMETER AND DMGG WIND
GUSTS...WILL CONTINUE SPREADING NWD/NEWD ACROSS WWS 246/247. THIS
ACTIVITY PRESENTLY RESIDES WITHIN A CORRIDOR OF RELATIVELY RICH
LOW-LEVEL MOISTURE /SFC DEWPOINTS IN THE UPPER 50S TO MIDDLE 60S/
CIRCULATING AROUND THE NRN/WRN SEMICIRCLES OF A SFC LOW ANALYZED
NEAR POWDER RIVER COUNTY MONTANA. SURMOUNTING STEEP MID-LEVEL LAPSE
RATES CONTINUE TO SUPPORT STRONG BUOYANCY...WITH AMPLE DEEP SHEAR
MAINTAINING ORGANIZED CONVECTION INCLUDING SUPERCELLS. SVR HAIL/WIND
WILL REMAIN POSSIBLE AS CONVECTION CONTINUES TO SPREAD NWD/NEWD. ANY
SUSTAINED RIGHT-MOVING SUPERCELLS MAY ALSO POSE THE POTENTIAL FOR
PRODUCING A BRIEF TORNADO...THOUGH NUMEROUS STORM INTERACTIONS
AMIDST A NOCTURNALLY COOLING BOUNDARY LAYER COULD MITIGATE SUCH
POTENTIAL.

WATER VAPOR IMAGERY IMPLIES FORCING FOR ASCENT BEGINNING TO OVERTAKE
THE PERIPHERY OF MOISTURE WRAPPING AROUND THE WRN SEMICIRCLE OF THE
LOW. THIS CORRESPONDS TO THE RECENT UPTICK IN CONVECTION FROM
ROSEBUD COUNTY TO GARFIELD COUNTY. AS FORCING FOR ASCENT CONTINUES
TO INCREASE ACROSS THIS AREA...MORE ORGANIZED CONVECTIVE CLUSTERS
MAY BECOME MORE CONCENTRATED IN WRN PARTS OF WW 246...SPREADING NWD.
A SWWD-ADVANCING BOUNDARY EVIDENT IN EARLIER KGGW RADAR LOOPS --
REPRESENTING THE LEADING EDGE OF COOLER AIR -- MAY HAVE A TENDENCY
OF UNDERCUTTING THE DEVELOPING CONVECTION. NEVERTHELESS...THE SVR
RISK MAY CONTINUE IF A COLD POOL WERE TO ORGANIZE CONCURRENT WITH
THE STRONGER ASCENT.

..COHEN.. 06/12/2016

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

ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...

LAT...LON   46630793 48190771 48670731 48960578 48710273 47190100
            45660086 45110215 45100556 44940741 46630793

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 8:56 PM MDTMesoscale DiscussionSPCDaniels, Dawson, McCone, Prairie, Richland, Roosevelt94 min
Jun 11, 10:04 PM MDTMesoscale DiscussionSPCAdams, Benson, Billings, Bottineau, Bowman, Burke and 20 more116 min
Jun 12, 1:30 PM MDTMesoscale DiscussionSPCBarnes, Cass, Dickey, LaMoure, Ransom, Richland and 2 more90 min
Jun 12, 1:50 PM MDTSevere Thunderstorm WatchSPCCass, Ransom, Richland, Sargent, Steele, Traill7 hr
Jun 12, 12:41 PM MDTMesoscale DiscussionSPCAurora, Brule, Buffalo, Gregory, Lyman, Tripp3 hr

Nearby

Mesoscale Discussions in Montana, 2016Mesoscale Discussions in North Dakota, 2016Mesoscale Discussions in South Dakota, 2016Every 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.