Alert archive / Montana / Mesoscale Discussions in 2016

Mesoscale Discussion 876

June 11, 201623 counties in Montana; 6 counties in North Dakota; Harding County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2016, 2:50 PM MDT for 23 counties in Montana; 6 counties in North Dakota; Harding County, South Dakota. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Jun 11, 2016, 2:50 PM MDT (20:50 UTC)
Expired: Jun 11, 2016, 4:15 PM MDT
In force: 85 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 30 counties

Big Horn County, MT, Carter County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, Fergus County, MT, Garfield County, MT, Golden Valley County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Stillwater County, MT, Treasure County, MT, Valley County, MT, Wibaux County, MT, Yellowstone County, MT, Billings County, ND, Bowman County, ND, Golden Valley County, ND, McKenzie County, ND, Slope County, ND, Williams County, ND, Harding County, SD

The radar

The Glasgow radar (KGGW), 154 km from the middle of the area, began a volume at 20:53 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.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 8.8 hours before the alert went out and 155 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2008 m above ground
0-6 km bulk shear: 68 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 300 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

260 
ACUS11 KWNS 112050
SWOMCD
SPC MCD 112050 
NDZ000-SDZ000-MTZ000-112215-

MESOSCALE DISCUSSION 0876
NWS STORM PREDICTION CENTER NORMAN OK
0350 PM CDT SAT JUN 11 2016

AREAS AFFECTED...CNTRL AND ERN MT...SW ND...FAR NW SD

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 112050Z - 112215Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A SEVERE THREAT APPEARS LIKELY TO DEVELOP ACROSS CNTRL AND
ERN MT INTO WRN ND LATE THIS AFTERNOON. WIND DAMAGE...ISOLATED LARGE
HAIL AND A TORNADO POSSIBLE. WW ISSUANCE WILL LIKELY BE NEEDED SOON.

DISCUSSION...LATEST SFC ANALYSIS SHOWS A 1003 MB LOW OVER NRN WY
WITH AN INVERTED TROUGH EXTENDING NNWWD ACROSS ERN MT. SFC DEWPOINTS
NEAR THE TROUGH ARE IN THE LOWER TO MID 60S F AND AN AXIS OF
MODERATE INSTABILITY IS ANALYZED FROM NRN SD WNWWD INTO ECNTRL MT
WHERE MLCAPE IS ESTIMATED IN THE 1500 TO 2500 J/KG RANGE. SOUTH OF
THE INSTABILITY AXIS...THUNDERSTORMS ARE DEVELOPING IN NRN WY. THIS
ACTIVITY IS FORECAST TO EXPAND IN COVERAGE...MOVING NWD INTO SRN AND
CNTRL MT OVER THE NEXT COUPLE OF HOURS. IN ADDITION...WIND FIELDS
ARE QUITE STRONG ACROSS THE MCD AREA WITH THE GLASGOW WSR-88D VWP
SHOWING 0-6 KM SHEAR NEAR 65 KT WITH SUBSTANTIAL DIRECTIONAL AND
SPEED SHEAR IN THE LOW TO MID-LEVELS. THIS WILL BE FAVORABLE FOR
STORM ROTATION AND SEVERAL SUPERCELLS WITH ISOLATED LARGE HAIL. WIND
DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY DUE TO THE STEEP LOW TO
MID-LEVEL LAPSE RATES.

..BROYLES/WEISS.. 06/11/2016

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

ATTN...WFO...BIS...UNR...BYZ...GGW...TFX...

LAT...LON   45090417 45230760 45530943 46570983 46930982 48050936
            48800821 48960576 48470353 47390289 45820311 45090417

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 10, 8:35 PM MDT	Mesoscale Discussion	SPC	Blaine, Cascade, Chouteau, Fergus, Garfield, Hill and 9 more	85 min
Jun 11, 5:25 AM MDT	Mesoscale Discussion	SPC	Blaine, Chouteau, Hill	95 min
Jun 11, 3:00 PM MDT	Severe Thunderstorm Watch	SPC	Big Horn, Carter, Custer, Daniels, Dawson, Fallon and 15 more	7 hr
Jun 11, 5:28 PM MDT	Mesoscale Discussion	SPC	Big Horn, Carter, Custer, Dawson, Fallon, Garfield and 9 more	92 min
Jun 11, 12:03 AM MDT	Mesoscale Discussion	SPC	Billings, Dunn, Mercer, Stark	87 min
Jun 11, 5:18 PM MDT	Mesoscale Discussion	SPC	Adams, Bowman, Grant, Hettinger, Sioux, Slope	117 min
Jun 11, 5:51 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Billings, Bowman, Burke, Divide, Dunn and 13 more	7 hr

Nearby

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