Alert archive / North Dakota / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 248

June 8, 202111 counties in North Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jun 8, 2021, 5:15 PM MDT for 11 counties in North Dakota. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 8, 2021, 5:15 PM MDT (23:15 UTC)
Expired: Jun 8, 2021, 11:57 PM MDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 65 kt

Counties Adams County, ND, Billings County, ND, Bowman County, ND, Divide County, ND, Dunn County, ND, Golden Valley County, ND, Hettinger County, ND, McKenzie County, ND, Slope County, ND, Stark County, ND, Williams County, ND

The radar

The Minot AFB radar (KMBX), 177 km from the middle of the area, began a volume at 23:17 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: 5%
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: 40%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 8, 5:32 PM MDT	Severe Thunderstorm Warning	BIS	Golden Valley, McKenzie	58 min
Jun 8, 6:25 PM MDT	Severe Thunderstorm Warning	BIS	Golden Valley, McKenzie	65 min
Jun 8, 7:12 PM MDT	Severe Thunderstorm Warning	BIS	McKenzie	20 min
Jun 8, 7:22 PM MDT	Severe Thunderstorm Warning	BIS	Billings, Dunn, McKenzie	38 min
Jun 8, 10:14 PM MDT	Severe Thunderstorm Warning	BIS	McKenzie, Williams	61 min
Jun 8, 10:58 PM MDT	Severe Thunderstorm Warning	BIS	Adams, Grant, Hettinger, Sioux	47 min
Jun 8, 11:01 PM MDT	Severe Thunderstorm Warning	BIS	Grant, Hettinger, Morton, Stark	59 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.3 hours before the alert went out and 209 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: 534 J/kg
Mixed-layer CIN: -518 J/kg
Mixed-layer LCL: 1161 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 267 m²/s²
0-3 km storm-relative helicity: 165 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -1.5

Open this sounding in Storm Lab

The text

As transmitted.

575 
WWUS20 KWNS 082312
SEL8  
SPC WW 082312
NDZ000-090600-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 248
NWS Storm Prediction Center Norman OK
515 PM MDT Tue Jun 8 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Western North Dakota

* Effective this Tuesday afternoon from 515 PM until Midnight
  MDT.

* Primary threats include...
  Scattered damaging winds and isolated significant gusts to 75
    mph possible
  Scattered large hail and isolated very large hail events to 2.5
    inches in diameter possible
  A tornado or two possible

SUMMARY...Severe storms developing in eastern Montana will spread
northeastward into western North Dakota this evening, with an
attendant threat for large hail and damaging winds.  A tornado or
two may occur early this evening with storms near the west central
North Dakota border, where supercells will interact with a surface
warm front and outflow boundary.

The severe thunderstorm watch area is approximately along and 35
statute miles east and west of a line from 60 miles north northeast
of Williston ND to 65 miles south southwest of Dickinson ND. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 246...WW 247...

AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
21020.

...Thompson

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 7, 7:35 PM MDT	Mesoscale Discussion	SPC	Barnes, Cass, Dickey, LaMoure, Logan, McIntosh and 1 more	85 min
Jun 7, 10:33 PM MDT	Mesoscale Discussion	SPC	Dickey, LaMoure, Ransom, Richland, Sargent	87 min
Jun 8, 2:36 AM MDT	Mesoscale Discussion	SPC	Barnes, LaMoure, Ransom, Richland, Sargent, Stutsman	84 min
Jun 8, 12:06 PM MDT	Mesoscale Discussion	SPC	Burleigh, Emmons, McLean, Morton, Oliver, Sheridan and 1 more	84 min
Jun 8, 2:39 PM MDT	Mesoscale Discussion	SPC	Divide, Golden Valley, McKenzie, Williams	3 hr

Nearby

Severe Thunderstorm Watches in North Dakota, 2021 Every severe thunderstorm watch in 2021

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.