Alert archive / Montana / Mesoscale Discussions in 2016
Mesoscale Discussion 845
The Storm Prediction Center issued this mesoscale discussion at Jun 8, 2016, 2:39 PM MDT for 15 counties in Montana. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 8, 2016, 2:39 PM MDT (20:39 UTC)
- Expired
- Jun 8, 2016, 5:15 PM MDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Broadwater County, MT, Cascade County, MT, Deer Lodge County, MT, Fergus County, MT, Gallatin County, MT, Golden Valley County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Madison County, MT, Meagher County, MT, Powell County, MT, Silver Bow County, MT, Sweet Grass County, MT, Wheatland County, MT
The radar
The Great Falls radar (KTFX), 102 km from the middle of the area, began a volume at 20:41 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 12:00Z, 8.7 hours before the alert went out and 115 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
- 12 J/kg
- Mixed-layer CIN
- -234 J/kg
- Mixed-layer LCL
- 2488 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 121 m²/s²
- 0-3 km storm-relative helicity
- 115 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
479
ACUS11 KWNS 082040
SWOMCD
SPC MCD 082039
MTZ000-082315-
MESOSCALE DISCUSSION 0845
NWS STORM PREDICTION CENTER NORMAN OK
0339 PM CDT WED JUN 08 2016
AREAS AFFECTED...PORTIONS OF CENTRAL AND SOUTHERN MONTANA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 082039Z - 082315Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...THERE WILL BE AN INCREASE IN THE POTENTIAL FOR ISOLATED
SEVERE THUNDERSTORMS ACROSS PORTIONS OF CNTRL/SRN MT DURING THE NEXT
FEW HOURS...WITH THIS ACTIVITY CONTINUING THROUGH EARLY EVENING.
WHILE CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED...WW ISSUANCE
IS PRESENTLY UNLIKELY.
DISCUSSION...TOWERING CUMULUS AND ISOLATED TSTM DEVELOPMENT ARE
ONGOING ACROSS PARTS OF THE BITTERROOT RANGE WITH ADDITIONAL CUMULUS
DEVELOPMENT INTO/ACROSS THE SWRN MT MOUNTAINS. DIURNALLY ENHANCED
OROGRAPHIC CIRCULATIONS IN THE STEEP-LAPSE-RATE ENVIRONMENT WILL BE
THE PRIMARY MEANS FOR TSTM DEVELOPMENT DURING THE NEXT FEW
HOURS...WHILE STRONGER DEEP ASCENT RESIDES WELL TO THE W/NW OF THE
DISCUSSION AREA. FURTHERMORE...WITH STRONGER DEEP SHEAR RESIDING TO
THE W/NW OF THE DISCUSSION AREA...CONVECTION SPREADING GENERALLY
ENEWD/EWD ACROSS THE PLAINS OF CNTRL/SRN MT FOLLOWING INITIAL
DEVELOPMENT OVER THE MOUNTAINS MAY LACK OVERALL ORGANIZATION.
NEVERTHELESS...A FEW LOOSELY ORGANIZED MULTICELL CLUSTERS MAY EVOLVE
GIVEN LARGE TEMPERATURE-DEWPOINT SPREADS -- E.G. AROUND 30-40F --
REFLECTING THE DEEPLY MIXED BOUNDARY LAYER THAT SHOULD FOSTER AMPLE
SUB-CLOUD EVAPORATION AND STRONG COLD POOLS. WITH DCAPE ALREADY
REACHING 1000-1250 J/KG...ISOLATED SVR WIND GUSTS MAY OCCUR...AND
ISOLATED SVR HAIL CANNOT BE RULED OUT WITH THE MOST INTENSE CORES.
HOWEVER...THE LACK OF STRONGER DEEP SHEAR...THE OVERALL DEARTH OF
MOISTURE...AND THE PAUCITY OF LARGE-SCALE ASCENT...WILL TEND TO
MARGINALIZE THE SVR POTENTIAL/COVERAGE.
..COHEN/DIAL.. 06/08/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BYZ...GGW...TFX...MSO...
LAT...LON 46571343 47591213 47881036 47450886 46670840 45640983
45091211 45421322 46571343SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 2:16 PM MDT | Mesoscale Discussion | SPC | Flathead, Glacier, Lake, Lincoln, Mineral, Missoula and 4 more | 2 hr |
| Jun 8, 3:07 PM MDT | Severe Thunderstorm Watch | SPC | Flathead, Lake, Lincoln, Mineral, Missoula, Sanders | 6 hr |
| Jun 8, 5:48 PM MDT | Mesoscale Discussion | SPC | Flathead, Glacier, Lake, Lincoln, Mineral, Missoula and 3 more | 57 min |
Nearby
Mesoscale Discussions in Montana, 2016Every 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.