Alert archive / Montana / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 271

June 18, 201620 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2016, 3:16 PM MDT for 20 counties in Montana. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jun 18, 2016, 3:16 PM MDT (21:16 UTC)
Expired
Jun 18, 2016, 11:40 PM MDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
70 kt

Counties Blaine County, MT, Cascade County, MT, Chouteau County, MT, Daniels County, MT, Dawson County, MT, Fergus County, MT, Garfield County, MT, Hill County, MT, Judith Basin County, MT, Liberty County, MT, McCone County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Toole County, MT, Valley County, MT, Wibaux County, MT

The radar

The Glasgow radar (KGGW), 131 km from the middle of the area, began a volume at 21:16 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 18, 5:36 PM MDTSevere Thunderstorm WarningTFXBlaine, Chouteau, Hill24 min
Jun 18, 5:54 PM MDTTornado WarningTFXBlaine36 min
Jun 18, 6:29 PM MDTSevere Thunderstorm WarningTFXBlaine31 min
Jun 18, 6:33 PM MDTSevere Thunderstorm WarningGGWPhillips57 min
Jun 18, 7:22 PM MDTSevere Thunderstorm WarningGGWPhillips, Valley53 min
Jun 18, 8:11 PM MDTSevere Thunderstorm WarningGGWDaniels, Roosevelt, Valley64 min
Jun 18, 8:21 PM MDTSevere Thunderstorm WarningGGWGarfield, McCone, Valley54 min
Jun 18, 8:45 PM MDTSevere Thunderstorm WarningGGWGarfield, McCone, Prairie60 min
Jun 18, 9:02 PM MDTSevere Thunderstorm WarningGGWDaniels, Dawson, McCone, Richland, Roosevelt, Sheridan and 1 more58 min
Jun 18, 9:45 PM MDTSevere Thunderstorm WarningGGWDawson, McCone, Prairie60 min
Jun 18, 9:54 PM MDTSevere Thunderstorm WarningGGWDaniels, Richland, Roosevelt, Sheridan66 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 9.3 hours before the alert went out and 133 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 2016-06-18Temperature 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 2016-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.19395878Sfc1 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
1606 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
279 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 18, 2:43 PM MDTMesoscale DiscussionSPCBlaine, Cascade, Chouteau, Daniels, Fergus, Garfield and 14 more92 min
Jun 18, 5:56 PM MDTMesoscale DiscussionSPCBlaine, Cascade, Chouteau, Daniels, Fergus, Garfield and 11 more2 hr

Nearby

Severe Thunderstorm Watches in Montana, 2016Every severe thunderstorm watch 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.