Alert archive / Montana / Mesoscale Discussions in 2012
Mesoscale Discussion 1284
The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2012, 10:27 PM MDT for 9 counties in Montana. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- Jun 25, 2012, 10:27 PM MDT (04:27 UTC)
- Expired
- Jun 26, 2012, 12:00 AM MDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
Counties Blaine County, MT, Chouteau County, MT, Fergus County, MT, Garfield County, MT, Hill County, MT, Liberty County, MT, Petroleum County, MT, Phillips County, MT, Toole County, MT
The radar
The Great Falls radar (KTFX), 142 km from the middle of the area, began a volume at 04:28 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, 4.5 hours before the alert went out and 96 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
- 1195 J/kg
- Mixed-layer CIN
- -265 J/kg
- Mixed-layer LCL
- 1952 m above ground
- 0-6 km bulk shear
- 59 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
175
ACUS11 KWNS 260427
SWOMCD
SPC MCD 260427
MTZ000-260600-
MESOSCALE DISCUSSION 1284
NWS STORM PREDICTION CENTER NORMAN OK
1127 PM CDT MON JUN 25 2012
AREAS AFFECTED...NWRN THROUGH NCNTRL MT
CONCERNING...SEVERE THUNDERSTORM WATCH 430...
VALID 260427Z - 260600Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 430
CONTINUES.
SUMMARY...AT LEAST A MODEST THREAT FOR ISOLATED STRONG TO DAMAGING
WIND GUSTS AND HAIL WILL PERSIST THROUGH 06Z.
DISCUSSION...STORMS HAVE BEEN INCREASING IN COVERAGE OVER NCNTRL MT
WITH OTHER ACTIVITY PERSISTING OVER NWRN MT MOST LIKELY WITHIN ZONE
OF MID LEVEL ASCENT ASSOCIATED WITH AN EJECTING UPPER JET STREAK.
OVERALL MARGINAL INTENSITY OF THE STORMS AND A STRONGLY CAPPED
BOUNDARY LAYER INDICATE ACTIVITY IS LIKELY DEVELOPING ABOVE THE
INVERSION AND ROOTED NEAR 700 MB...WHICH SUBSTANTIALLY LOWERS THE
AMOUNT OF CAPE AVAILABLE TO THE UPDRAFTS. NEVERTHELESS...THE STEEP
LAPSE RATES AND PRESENCE OF DRY AIR BETWEEN 850 AND 700 MB SUGGEST A
FEW STORMS MIGHT REMAIN CAPABLE OF PRODUCING ISOLATED LOCALLY STRONG
WIND GUSTS AND HAIL NEXT HOUR OR TWO.
..DIAL.. 06/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GGW...TFX...
LAT...LON 48791225 48920884 48720697 47030664 46890930 47521185
48791225SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 7:12 PM MDT | Mesoscale Discussion | SPC | Blaine, Chouteau, Dawson, Fergus, Garfield, Hill and 11 more | 93 min |
| Jun 26, 12:23 AM MDT | Mesoscale Discussion | SPC | Blaine, Chouteau, Hill | 67 min |
| Jun 26, 6:16 AM MDT | Mesoscale Discussion | SPC | Glacier, Hill, Liberty, Pondera, Teton, Toole | 89 min |
| Jun 26, 11:08 AM MDT | Mesoscale Discussion | SPC | Blaine, Cascade, Chouteau, Glacier, Hill, Liberty and 3 more | 37 min |
| Jun 26, 11:20 AM MDT | Severe Thunderstorm Watch | SPC | Blaine, Cascade, Chouteau, Glacier, Hill, Lewis and Clark and 4 more | 6 hr |
| Jun 26, 2:06 PM MDT | Mesoscale Discussion | SPC | Daniels, Dawson, Fallon, McCone, Phillips, Prairie and 5 more | 54 min |
| Jun 26, 2:21 PM MDT | Mesoscale Discussion | SPC | Blaine, Cascade, Chouteau, Hill, Lewis and Clark, Liberty and 3 more | 54 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.