Alert archive / North Dakota / Mesoscale Discussions in 2021

Mesoscale Discussion 858

June 6, 202120 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 6, 2021, 1:22 AM CDT for 20 counties in North Dakota. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued: Jun 6, 2021, 1:22 AM CDT (06:22 UTC)
Expired: Jun 6, 2021, 3:15 AM CDT
In force: 113 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 238

Counties Benson County, ND, Burleigh County, ND, Cavalier County, ND, Eddy County, ND, Emmons County, ND, Foster County, ND, Grant County, ND, Kidder County, ND, Morton County, ND, Nelson County, ND, Pembina County, ND, Pierce County, ND, Ramsey County, ND, Rolette County, ND, Sheridan County, ND, Sioux County, ND, Stutsman County, ND, Towner County, ND, Walsh County, ND, Wells County, ND

The radar

The Minot AFB radar (KMBX), 116 km from the middle of the area, began a volume at 06:22 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.

Severe Thunderstorm Watch 239Jun 6, 1:35 AM CDT

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 6.4 hours before the alert went out and 155 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: 1639 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 3032 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 118 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

As transmitted.

054 
ACUS11 KWNS 060622
SWOMCD
SPC MCD 060622 
NDZ000-SDZ000-060815-

Mesoscale Discussion 0858
NWS Storm Prediction Center Norman OK
0122 AM CDT Sun Jun 06 2021

Areas affected...Much of central into northeastern North Dakota

Concerning...Severe Thunderstorm Watch 238...

Valid 060622Z - 060815Z

The severe weather threat for Severe Thunderstorm Watch 238
continues.

SUMMARY...Strong to occasionally severe wind gusts likely will
continue to accompany thunderstorm activity spreading across much of
central through northeastern North Dakota by 2-4 AM CDT.  A new
severe thunderstorm watch probably will be issued for parts of
northeastern North Dakota shortly.

DISCUSSION...Large-scale forcing for ascent, aided by lower/mid
tropospheric warming advection, ahead of mid-level troughing
progressing northeastward across the northern Rockies, is
maintaining an ongoing cluster of thunderstorms.  Convection appears
mostly rooted above its associated conglomerate outflow, which has
been surging east-northeastward around 40 kts.  

Despite the elevated nature of the convection, a deep, remnant
sub-cloud mixed layer, above the shallow outflow, is still allowing
for substantive evaporative cooling/melting to contribute to strong
downdrafts beneath stronger storms, as well as downward mixing of
50+ kt rear inflow evident in Minot radar data.  This seems likely
to continue at least another several hours, with activity likely
spreading across and northeast of the Devils Lake area through
07-09Z.

..Kerr.. 06/06/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FGF...ABR...BIS...UNR...

LAT...LON   49089729 48019774 46519940 45720196 46080235 47780065
            49010024 49799854 49089729

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 5, 9:15 PM CDT	Mesoscale Discussion	SPC	Adams, Benson, Billings, Bowman, Burleigh, Dunn and 16 more	2 hr
Jun 5, 10:21 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Billings, Bowman, Burleigh, Dunn, Foster and 16 more	5 hr
Jun 5, 11:47 PM CDT	Mesoscale Discussion	SPC	Adams, Bowman, Dunn, Grant, Hettinger, McHenry and 8 more	88 min
Jun 6, 1:39 AM CDT	Severe Thunderstorm Watch	SPC	Benson, Cavalier, Eddy, Grand Forks, Griggs, Nelson and 6 more	3 hr
Jun 6, 2:52 AM CDT	Mesoscale Discussion	SPC	McLean, Oliver, Sheridan, Wells	53 min

Nearby

Mesoscale Discussions in North Dakota, 2021 Every mesoscale discussion 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.