Alert archive / Montana / Mesoscale Discussions in 2012

Mesoscale Discussion 1064

June 4, 20127 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2012, 8:22 PM MDT for 7 counties in Montana. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Jun 4, 2012, 8:22 PM MDT (02:22 UTC)
Expired: Jun 4, 2012, 9:45 PM MDT
In force: 83 min
Issued by: the Storm Prediction Center

Counties Blaine County, MT, Chouteau County, MT, Fergus County, MT, Hill County, MT, Petroleum County, MT, Phillips County, MT, Treasure County, MT

The radar

The Glasgow radar (KGGW), 168 km from the middle of the area, began a volume at 02:25 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, 2.4 hours before the alert went out and 143 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: 2217 m above ground
0-6 km bulk shear: 69 kt
0-1 km storm-relative helicity: 182 m²/s²
0-3 km storm-relative helicity: 469 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

451 
ACUS11 KWNS 050222
SWOMCD
SPC MCD 050222 
MTZ000-050345-

MESOSCALE DISCUSSION 1064
NWS STORM PREDICTION CENTER NORMAN OK
0922 PM CDT MON JUN 04 2012

AREAS AFFECTED...N-CNTRL/NERN MT

CONCERNING...TORNADO WATCH 355...

VALID 050222Z - 050345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 355 CONTINUES.

SUMMARY...PRIMARY NEAR-TERM SEVERE THREAT EXISTS WITH SUPERCELL
STRUCTURE EMBEDDED WITHIN A TSTM CLUSTER CENTERED OVER CHOUTEAU
COUNTY. MONITORING ITS EVOLUTION FOR ITS POTENTIAL AFFECT ON
PORTIONS OF NERN MT AND POSSIBLE WW ISSUANCE.

DISCUSSION...INTENSE TSTM CLUSTER CENTERED OVER CHOUTEAU COUNTY HAS
HAD A HISTORY OF REPORTED SIGNIFICANT SEVERE HAIL AND SEVERE WIND
GUSTS. TORNADIC THREAT ASSOCIATED WITH THIS STORM SHOULD CONTINUE TO
INCREASE AS IT BEGINS TO INGEST UPPER 50S SURFACE DEW POINTS AMIDST
ENLARGING CYCLONIC HODOGRAPHS. CURRENT EXTRAPOLATION WILL TAKE THIS
CELL E/NEWD...THAT IF MAINTAINED...MAY GRAZE PORTIONS OF NERN MT
PRIOR TO MOVING INTO SASKATCHEWAN. FARTHER SE...CONVECTION ACROSS
S-CNTRL/SERN MT COULD INTENSIFY AS IT ENCOUNTERS THE LOW-LEVEL MOIST
AXIS ANCHORED ALONG THE UPPER MO VALLEY. BUT AS THE BOUNDARY LAYER
COOLS AND WITH STRONGER LARGE-SCALE ASCENT REMAINING FARTHER
WEST...THERE IS UNCERTAINTY OVER THIS SCENARIO WITH SEVERE POTENTIAL
LIKELY TO REMAIN MARGINAL OVER MOST OF ERN MT.

..GRAMS.. 06/05/2012

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

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

LAT...LON   48031128 48671057 49000999 49070897 49000721 48170753
            47150712 46660632 46350634 46090706 46410807 46880963
            47421061 48031128

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 4, 6:02 PM MDT	Tornado Watch	SPC	Blaine, Cascade, Chouteau, Fergus, Glacier, Hill and 6 more	7 hr
Jun 4, 7:42 PM MDT	Mesoscale Discussion	SPC	Granite, Lake, Lincoln, Mineral, Missoula, Ravalli and 1 more	93 min
Jun 4, 10:08 PM MDT	Mesoscale Discussion	SPC	Lake, Lincoln, Mineral, Sanders	67 min
Jun 4, 10:48 PM MDT	Mesoscale Discussion	SPC	Liberty, Pondera, Teton, Toole	57 min
Jun 5, 12:54 PM MDT	Mesoscale Discussion	SPC	Broadwater, Carbon, Gallatin, Golden Valley, Madison, Meagher and 6 more	2 hr
Jun 5, 1:37 PM MDT	Severe Thunderstorm Watch	SPC	Broadwater, Carbon, Gallatin, Golden Valley, Jefferson, Madison and 5 more	7 hr
Jun 5, 1:56 PM MDT	Mesoscale Discussion	SPC	Blaine, Cascade, Chouteau, Fergus, Glacier, Hill and 8 more	2 hr
Jun 5, 2:37 PM MDT	Tornado Watch	SPC	Blaine, Cascade, Chouteau, Fergus, Glacier, Hill and 6 more	8 hr
Jun 5, 4:21 PM MDT	Mesoscale Discussion	SPC	Broadwater, Golden Valley, Meagher, Stillwater, Sweet Grass, Wheatland	84 min
Jun 5, 4:48 PM MDT	Mesoscale Discussion	SPC	Cascade, Chouteau, Fergus, Glacier, Golden Valley, Judith Basin and 6 more	87 min

Nearby

Mesoscale Discussions in Montana, 2012 Every mesoscale discussion in 2012

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.