Alert archive / Montana / Mesoscale Discussions in 2012
Mesoscale Discussion 1081
The Storm Prediction Center issued this mesoscale discussion at Jun 5, 2012, 8:08 PM MDT for 8 counties in Montana. It was in force for 67 min.
The area
The outline as issued.
The facts
- Issued
- Jun 5, 2012, 8:08 PM MDT (02:08 UTC)
- Expired
- Jun 5, 2012, 9:15 PM MDT
- In force
- 67 min
- Issued by
- the Storm Prediction Center
Counties Blaine County, MT, Cascade County, MT, Chouteau County, MT, Hill County, MT, Liberty County, MT, Pondera County, MT, Teton County, MT, Toole County, MT
The radar
The Great Falls radar (KTFX), 93 km from the middle of the area, began a volume at 02:10 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, 2.1 hours before the alert went out and 297 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.
- Mixed-layer CAPE
- 880 J/kg
- Mixed-layer CIN
- -226 J/kg
- Mixed-layer LCL
- 2578 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 244 m²/s²
- 0-3 km storm-relative helicity
- 359 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
788
ACUS11 KWNS 060208
SWOMCD
SPC MCD 060208
MTZ000-060315-
MESOSCALE DISCUSSION 1081
NWS STORM PREDICTION CENTER NORMAN OK
0908 PM CDT TUE JUN 05 2012
AREAS AFFECTED...N-CNTRL MT
CONCERNING...TORNADO WATCH 360...
VALID 060208Z - 060315Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 360 CONTINUES.
SUMMARY...GREATEST NEAR-TERM SUPERCELL THREAT EXISTS WITH TSTMS
SHIFTING NWD TO THE W OF HVR...WITH TORNADOES...LARGE HAIL AND
DAMAGING WINDS PROBABLE. ELSEWHERE...MARGINALLY SEVERE HAIL RISK
PERSISTS FARTHER W IN WW 360.
DISCUSSION...A LONG-TRACK SUPERCELL WITH A HISTORY OF REPORTED
TORNADOES AND LARGE HAIL HAS RECENTLY WEAKENED AS IT INTERACTED WITH
THE LITTLE ROCKIES AND MERGED WITH A SUPERCELL TO THE WEST IN
N-CNTRL CHOUTEAU COUNTY. THIS CLUSTER SHOULD CONTINUE TO PROGRESS
NWD ACROSS HILL COUNTY BEFORE MOVING CROSSING THE CANADIAN BORDER.
LOW-LEVEL E/SELYS HAVE STRENGTHENED IN THE PAST COUPLE OF HOURS IN
THE GGW VWP WITH 0-1 KM SRH AOA 300 M2/S2. GIVEN INFLOW OF AROUND 60
DEG F SURFACE DEW POINTS...SETUP WILL REMAIN FAVORABLE FOR POTENTIAL
RESTRENGTHENING OF MESOCYCLONES AND ATTENDANT THREATS FOR ALL TYPES
OF SEVERE WEATHER.
ELSEWHERE...COMPOSITE COLD FRONT/CONVECTIVE OUTFLOW HAS SURGED EAST
OF LWT TO LVM WITH ABUNDANT TSTM CLUSTERS AND STRATIFORM SHIELD
ENCOMPASSING MUCH OF THE WRN TWO-THIRDS OF WW 360. GIVEN THE
STRENGTH OF THE DEEP-LAYER SHEAR...MARGINALLY SEVERE HAIL AND
PERHAPS A STRONG WIND GUST OR TWO IS STILL POSSIBLE...BUT INCREASING
STABILIZATION SHOULD MITIGATE REINTENSIFICATION OF THE OVERALL
THREAT.
..GRAMS.. 06/06/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...TFX...
LAT...LON 49000858 48050859 47710997 47091103 47121204 47611239
48421230 48961192 49000858SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 5, 6:07 PM MDT | Mesoscale Discussion | SPC | Hill, Judith Basin | 53 min |
| Jun 5, 7:39 PM MDT | Mesoscale Discussion | SPC | Broadwater | 66 min |
| Jun 5, 9:49 PM MDT | Mesoscale Discussion | SPC | Chouteau, Liberty, Toole | 56 min |
Nearby
Mesoscale Discussions in Montana, 2012Every 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.