Alert archive / Montana / Mesoscale Discussions in 2016

Mesoscale Discussion 895

June 13, 20168 counties in Montana; 6 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 13, 2016, 1:37 PM MDT for 8 counties in Montana; 6 counties in North Dakota. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Jun 13, 2016, 1:37 PM MDT (19:37 UTC)
Expired
Jun 13, 2016, 2:30 PM MDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Daniels County, MT, Dawson County, MT, Garfield County, MT, McCone County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Valley County, MT, Burke County, ND, Divide County, ND, Dunn County, ND, McKenzie County, ND, Mountrail County, ND, Williams County, ND

The radar

The Glasgow radar (KGGW), 115 km from the middle of the area, began a volume at 19:40 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 7.6 hours before the alert went out and 113 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-pSkew-T log-p diagram, Glasgow Intl Airport, MT at 12:00Z on 2016-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Glasgow Intl Airport, MT at 12:00Z on 2016-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
2468 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

371 
ACUS11 KWNS 131938
SWOMCD
SPC MCD 131937 
NDZ000-MTZ000-132030-

MESOSCALE DISCUSSION 0895
NWS STORM PREDICTION CENTER NORMAN OK
0237 PM CDT MON JUN 13 2016

AREAS AFFECTED...NERN MT...NWRN ND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 131937Z - 132030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...AN ISOLATED THREAT FOR SVR HAIL/WIND MAY ACCOMPANY
DEVELOPING TSTMS ACROSS NERN MT INTO NWRN ND THIS AFTERNOON. IT IS
UNCERTAIN WHETHER COVERAGE OF THESE THREATS WILL BE SUFFICIENT FOR
AREAL EXPANSION OF WATCH 249 OR ISSUANCE A NEW WW...BUT CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED.

DISCUSSION...RECENT SATELLITE/RADAR TRENDS SHOW AN INCREASE IN
RECENT TSTM DEVELOPMENT ACROSS FAR NERN MT...EVOLVING OUT OF
REMNANTS OF EARLIER CONVECTION FROM E-CNTRL MT. THIS ACTIVITY IS
OCCURRING ALONG THE NRN FRINGE OF RELATIVELY RICHER LOW-LEVEL
MOISTURE...WITH INFLOW AIR CHARACTERIZED BY MID-UPPER 50S F
DEWPOINTS OVER E-CNTRL MT. ADDITIONAL CONVECTION DEVELOPING OVER THE
HIGH TERRAIN OF N-CNTRL MT MAY CONTINUE STRENGTHENING THIS AFTERNOON
WITH EWD PROGRESSION INTO NERN MT AS IT ENTERS A MORE FAVORABLE AIR
MASS. 

STEEP MIDLEVEL LAPSE RATES COUPLED WITH MODERATELY STRONG MID-UPPER
LEVEL FLOW WILL SUPPORT THE POTENTIAL FOR ISOLATED LARGE HAIL
ACCOMPANYING ANY ORGANIZED TSTM THAT CAN DEVELOP.  ISOLATED STRONG
TO DMGG WIND GUSTS WILL ALSO BE POSSIBLE. THE RELATIVELY NARROW
LONGITUDINAL EXTENT OF RICHER LOW-LEVEL MOISTURE SHOULD LIMIT THE
POTENTIAL FOR STRONGER CONVECTION TO WRN PORTIONS OF ND. CONVECTIVE
TRENDS WILL BE MONITORED FOR INCREASING COVERAGE OF ANY POTENTIAL
SVR THREAT...FOR POSSIBLE AREAL EXPANSION OF SVR TSTM WATCH 249 OR
ISSUANCE OF A NEW WW.

..ROGERS/GUYER.. 06/13/2016

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

ATTN...WFO...BIS...GGW...

LAT...LON   49000428 48990223 48200208 47090204 47010520 46880659
            46910772 47420786 48250778 48990623 49000428

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 13, 12:00 PM MDTMesoscale DiscussionSPCBig Horn, Powder River60 min
Jun 13, 12:45 PM MDTSevere Thunderstorm WatchSPCBig Horn, Carter, Custer, Fallon, Powder River, Prairie and 3 more9 hr
Jun 13, 2:51 PM MDTMesoscale DiscussionSPCBig Horn, Carter, Custer, Fallon, Powder River, Rosebud and 2 more54 min
Jun 13, 3:40 PM MDTMesoscale DiscussionSPCDaniels, Dawson, Garfield, McCone, Richland, Roosevelt and 3 more95 min
Jun 13, 4:07 PM MDTSevere Thunderstorm WatchSPCDawson, Garfield, McCone, Prairie, Richland, Roosevelt and 2 more4 hr

Nearby

Mesoscale Discussions in Montana, 2016Mesoscale Discussions in North Dakota, 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.