Alert archive / Montana / Mesoscale Discussions in 2016
Mesoscale Discussion 920
The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2016, 4:03 PM MDT for 6 counties in Montana. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 14, 2016, 4:03 PM MDT (22:03 UTC)
- Expired
- Jun 14, 2016, 6:30 PM MDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Blaine County, MT, Daniels County, MT, McCone County, MT, Phillips County, MT, Roosevelt County, MT, Valley County, MT
The radar
The Glasgow radar (KGGW), 35 km from the middle of the area, began a volume at 22:05 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 12:00Z, 10.1 hours before the alert went out and 37 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1312 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 78 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
108
ACUS11 KWNS 142203
SWOMCD
SPC MCD 142203
MTZ000-150030-
MESOSCALE DISCUSSION 0920
NWS STORM PREDICTION CENTER NORMAN OK
0503 PM CDT TUE JUN 14 2016
AREAS AFFECTED...PORTIONS OF NERN MT
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 142203Z - 150030Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED SVR POTENTIAL WILL ACCOMPANY TSTMS SPREADING
ACROSS PARTS OF NERN MT THROUGH THE LATE AFTERNOON/EARLY EVENING
HOURS. WHILE CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED...WW
ISSUANCE IS PRESENTLY UNLIKELY.
DISCUSSION...A FORWARD-PROPAGATING CONVECTIVE CLUSTER BETWEEN HAVRE
AND LEWISTOWN WILL CONTINUE SPREADING EWD/NEWD ACROSS PARTS OF NERN
MT. THIS ACTIVITY LIES WITHIN THE PERIPHERY OF ASCENT ACCOMPANYING A
MID-LEVEL SHORTWAVE IMPULSE GLANCING THE AREA...WHICH IS ORBITING
THE ERN SEMI-CIRCLE OF A DEEP CYCLONE ANCHORED OVER SWRN BRITISH
COLUMBIA PER WATER VAPOR LOOPS. INFLOW FOR THE ONGOING CONVECTION
REMAINS MODERATELY UNSTABLE...AS MIDDLE 50S DEWPOINTS ARE SAMPLED
ACROSS NERN MT PER SFC OBS -- WHICH ARE RELATIVELY MOIST FOR THESE
ELEVATIONS. WITH STEEP TROPOSPHERIC LAPSE RATES IN PLACE...COUPLED
WITH 30-45 KT OF EFFECTIVE BULK SHEAR...MAINTAINED ORGANIZED
CONVECTIVE CLUSTERS WITH LOCALLY/MARGINALLY SVR WIND/HAIL MAY OCCUR.
HOWEVER...GIVEN THE ONLY GLANCING INFLUENCE OF STRONGER ASCENT...AND
GIVEN THE TENDENCY FOR PREFERENTIAL CELL DEVELOPMENT/PROPAGATION TO
CARRY THE CONVECTION INTO PROGRESSIVELY WEAKER DEEP SHEAR EWD IN
MT...ANY SVR RISK SHOULD BE ISOLATED.
..COHEN/CORFIDI.. 06/14/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GGW...TFX...
LAT...LON 47990907 48910908 48910503 48420434 47500503 47500803
47990907SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 13, 6:00 PM MDT | Mesoscale Discussion | SPC | Carter, Custer, Dawson, Fallon, McCone, Powder River and 5 more | 90 min |
| Jun 14, 1:00 PM MDT | Mesoscale Discussion | SPC | Blaine, Broadwater, Cascade, Chouteau, Fergus, Gallatin and 6 more | 2 hr |
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.