Alert archive / North Dakota / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 255

June 11, 202123 counties in North Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jun 11, 2021, 1:58 AM CDT for 23 counties in North Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jun 11, 2021, 1:58 AM CDT (06:58 UTC)
Expired
Jun 11, 2021, 7:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 23 counties

Barnes County, ND, Benson County, ND, Cass County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Nelson County, ND, Pembina County, ND, Ramsey County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Traill County, ND, Walsh County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 57 km from the middle of the area, began a volume at 06:58 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
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 11, 2:33 AM CDTSevere Thunderstorm WarningBISEmmons, Kidder, Logan, Stutsman57 min
Jun 11, 3:23 AM CDTSevere Thunderstorm WarningFGFBenson, Eddy, Griggs, Nelson, Ramsey, Steele67 min
Jun 11, 3:43 AM CDTSevere Thunderstorm WarningBISDickey, Foster, LaMoure, Logan, McIntosh, Stutsman47 min
Jun 11, 3:48 AM CDTSevere Thunderstorm WarningFGFBarnes, Cass, Griggs, Steele57 min
Jun 11, 4:07 AM CDTSevere Thunderstorm WarningFGFBarnes, Cass, Ransom, Richland, Sargent38 min
Jun 11, 4:19 AM CDTSevere Thunderstorm WarningFGFCass, Grand Forks, Nelson, Steele, Traill, Walsh56 min
Jun 11, 4:28 AM CDTSevere Thunderstorm WarningFGFBenson, Eddy, Griggs, Nelson, Ramsey, Steele62 min
Jun 11, 4:36 AM CDTSevere Thunderstorm WarningFGFCavalier, Nelson, Pembina, Ramsey, Towner, Walsh54 min
Jun 11, 4:42 AM CDTSevere Thunderstorm WarningFGFBarnes, Cass, Ransom, Richland, Sargent63 min
Jun 11, 4:47 AM CDTSevere Thunderstorm WarningFGFBarnes, Cass, Griggs, Steele28 min
Jun 11, 5:07 AM CDTSevere Thunderstorm WarningFGFCass, Grand Forks, Nelson, Steele, Traill, Walsh68 min
Jun 11, 5:39 AM CDTSevere Thunderstorm WarningFGFCass, Richland66 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 00:00Z, 7.0 hours before the alert went out and 230 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, Bismarck Municip, ND at 00:00Z on 2021-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1785 joules per kilogram.LCLLFCEL10008507005003002001001 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, Bismarck Municip, ND at 00:00Z on 2021-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 square meters per square second.193958Sfc1 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
1785 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
2484 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
210 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.8

Open this sounding in Storm Lab

The text

As transmitted.

089 
WWUS20 KWNS 110655
SEL5  
SPC WW 110655
MNZ000-NDZ000-111200-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 255
NWS Storm Prediction Center Norman OK
200 AM CDT Fri Jun 11 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  A small part of northwestern Minnesota
  Eastern North Dakota

* Effective this Friday morning from 200 AM until 700 AM CDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph possible
  Isolated large hail events to 1 inch in diameter possible

SUMMARY...A squall line in central North Dakota will continue to
move generally eastward through the early morning hours, with the
threat for occasional damaging gusts and marginally severe hail
before the storms weaken after moving into western Minnesota toward
sunrise.

The severe thunderstorm watch area is approximately along and 65
statute miles east and west of a line from 60 miles north northeast
of Devils Lake ND to 70 miles south southeast of Jamestown ND. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU5).

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 253...WW 254...

AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
25035.

...Thompson

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 10, 8:30 PM CDTMesoscale DiscussionSPCBillings, Burke, Divide, Golden Valley, McKenzie, Mountrail and 1 more2 hr
Jun 10, 9:54 PM CDTSevere Thunderstorm WatchSPCAdams, Billings, Bottineau, Bowman, Burke, Burleigh and 24 more5 hr
Jun 10, 11:07 PM CDTMesoscale DiscussionSPCAdams, Bowman, Grant, Hettinger, Slope, Stark83 min
Jun 10, 11:21 PM CDTMesoscale DiscussionSPCBottineau, Burke, Divide, McHenry, McKenzie, Mountrail and 3 more114 min
Jun 11, 12:52 AM CDTMesoscale DiscussionSPCBarnes, Benson, Cass, Cavalier, Dickey, Eddy and 17 more53 min
Jun 11, 4:37 AM CDTMesoscale DiscussionSPCBarnes, Cass, Cavalier, Grand Forks, Griggs, Nelson and 8 more83 min

Nearby

Severe Thunderstorm Watches in North Dakota, 2021Every 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.