Alert archive / Montana / Mesoscale Discussions in 2016

Mesoscale Discussion 874

June 11, 2016Blaine County, Chouteau County, Hill County, Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2016, 5:25 AM MDT for Blaine County, Chouteau County, Hill County, Montana. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jun 11, 2016, 5:25 AM MDT (11:25 UTC)
Expired: Jun 11, 2016, 7:00 AM MDT
In force: 95 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Blaine County, MT, Chouteau County, MT, Hill County, MT

The radar

The Great Falls radar (KTFX), 159 km from the middle of the area, began a volume at 11:25 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

Great_falls, MT (KTFX), launched 00:00Z, 11.4 hours before the alert went out and 119 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: 603 J/kg
Mixed-layer CIN: -97 J/kg
Mixed-layer LCL: 1834 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: -73 m²/s²
0-3 km storm-relative helicity: 53 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -2.7

Open this sounding in Storm Lab

The text

As transmitted.

560 
ACUS11 KWNS 111126
SWOMCD
SPC MCD 111125 
MTZ000-111300-

MESOSCALE DISCUSSION 0874
NWS STORM PREDICTION CENTER NORMAN OK
0625 AM CDT SAT JUN 11 2016

AREAS AFFECTED...NORTH-CENTRAL MT

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 111125Z - 111300Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A SWATH OF SEVERE HAIL IS POSSIBLE THROUGH ABOUT 13-14Z
BEFORE FAST-MOVING ELEVATED STORMS LIKELY PROGRESS INTO
SASKATCHEWAN.

DISCUSSION...A COUPLE OF ELEVATED CELLS HAVE RECENTLY INTENSIFIED
NEAR/NORTH OF THE GREAT FALLS AREA...YIELDING HAIL REPORTED UP TO
1.5 INCH IN DIAMETER. THIS ACTIVITY APPEARS TO BE AIDED IN
LARGE-SCALE ASCENT DOWNSTREAM OF A MID-LEVEL VORTICITY MAX SHIFTING
NORTH ALONG THE INTERNATIONAL BORDER ACROSS THE SOUTHERN CANADIAN
ROCKIES. OVERALL ENVIRONMENT IS CHARACTERIZED BY PROBABLE WEAK
ELEVATED BUOYANCY...BUT A RATHER ELONGATED MID/UPPER-LEVEL HODOGRAPH
GIVEN THE STRONG SPEED SHEAR SAMPLED BY TFX VWP DATA. AS SUCH...THE
PRIMARY HAZARD WILL BE HAIL. CURRENT NORTHEASTERLY STORM MOTIONS
AROUND 45 KT SUGGEST ACTIVITY WILL SHIFT ACROSS THE INTERNATIONAL
BORDER BETWEEN 13-14Z.

..GRAMS/HART.. 06/11/2016

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

ATTN...WFO...GGW...TFX...

LAT...LON   48461078 49031032 49000781 48590793 47930924 47641017
            47701071 48461078

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, 2:50 PM MDT	Mesoscale Discussion	SPC	Big Horn, Carter, Custer, Daniels, Dawson, Fallon and 17 more	85 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

Nearby

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.