Alert archive / Montana / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 196

May 28, 201419 counties in Montana; 4 counties in Wyoming

The Storm Prediction Center issued this severe thunderstorm watch at May 28, 2014, 2:47 PM MDT for 19 counties in Montana; 4 counties in Wyoming. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 28, 2014, 2:47 PM MDT (20:47 UTC)
Expired: May 28, 2014, 8:21 PM MDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 65 kt

All 23 counties

Big Horn County, MT, Broadwater County, MT, Carbon County, MT, Cascade County, MT, Custer County, MT, Gallatin County, MT, Golden Valley County, MT, Jefferson County, MT, Lewis and Clark County, MT, Meagher County, MT, Musselshell County, MT, Park County, MT, Powder River County, MT, Rosebud County, MT, Stillwater County, MT, Sweet Grass County, MT, Treasure County, MT, Wheatland County, MT, Yellowstone County, MT, Big Horn County, WY, Johnson County, WY, Sheridan County, WY, Washakie County, WY

The radar

The Billings radar (KBLX), 88 km from the middle of the area, began a volume at 20:49 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: 10%
One or more EF2 to EF5 tornadoes: 10%
Ten or more severe wind reports: 40%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 60%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 28, 4:31 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Treasure, Yellowstone	59 min
May 28, 4:36 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau, Teton	39 min
May 28, 4:45 PM MDT	Severe Thunderstorm Warning	BYZ	Sheridan	30 min
May 28, 4:47 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	43 min
May 28, 5:24 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau, Liberty	51 min
May 28, 5:38 PM MDT	Severe Thunderstorm Warning	BYZ	Rosebud	67 min
May 28, 5:39 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau	51 min
May 28, 5:49 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau, Judith Basin	56 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

Great_falls, MT (KTFX), launched 12:00Z, 8.8 hours before the alert went out and 181 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 194 J/kg
Mixed-layer CIN: -319 J/kg
Mixed-layer LCL: 1098 m above ground
0-6 km bulk shear: 78 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 161 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 27, 6:12 PM MDT	Mesoscale Discussion	SPC	Broadwater, Cascade, Deer Lodge, Fergus, Golden Valley, Granite and 6 more	48 min
May 27, 10:58 PM MDT	Mesoscale Discussion	SPC	Custer, Fallon, Musselshell, Prairie, Rosebud, Treasure	62 min
May 28, 2:51 AM MDT	Mesoscale Discussion	SPC	Dawson, Prairie, Wibaux	114 min
May 28, 2:12 PM MDT	Mesoscale Discussion	SPC	Big Horn, Blaine, Broadwater, Carbon, Cascade, Chouteau and 17 more	2 hr
May 28, 4:59 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Chouteau, Daniels, Dawson, Fergus, Garfield and 12 more	7 hr
May 27, 6:06 PM MDT	Mesoscale Discussion	SPC	Campbell, Crook, Johnson, Washakie, Weston	54 min
May 28, 2:02 PM MDT	Mesoscale Discussion	SPC	Big Horn, Fremont, Hot Springs, Lincoln, Park, Sublette and 3 more	118 min

Nearby

Severe Thunderstorm Watches in Montana, 2014 Severe Thunderstorm Watches in Wyoming, 2014 Every severe thunderstorm watch in 2014

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.