Alert archive / North Dakota / Mesoscale Discussions in 2021
Mesoscale Discussion 856
The Storm Prediction Center issued this mesoscale discussion at Jun 5, 2021, 8:15 PM MDT for 22 counties in North Dakota. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 5, 2021, 8:15 PM MDT (02:15 UTC)
- Expired
- Jun 5, 2021, 10:15 PM MDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 40%
All 22 counties
Adams County, ND, Benson County, ND, Billings County, ND, Bowman County, ND, Burleigh County, ND, Dunn County, ND, Eddy County, ND, Foster County, ND, Grant County, ND, Hettinger County, ND, Kidder County, ND, McHenry County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Oliver County, ND, Pierce County, ND, Ramsey County, ND, Sheridan County, ND, Slope County, ND, Stark County, ND, Wells County, ND
The radar
The Bismarck radar (KBIS), 70 km from the middle of the area, began a volume at 02:18 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.
The nearest sounding before it
Bismarck Municip, ND (KBIS), launched 00:00Z, 2.3 hours before the alert went out and 73 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.
- 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
The text
As transmitted.
377
ACUS11 KWNS 060216
SWOMCD
SPC MCD 060215
NDZ000-SDZ000-MTZ000-060415-
Mesoscale Discussion 0856
NWS Storm Prediction Center Norman OK
0915 PM CDT Sat Jun 05 2021
Areas affected...Portions of North Dakota
Concerning...Severe potential...Watch possible
Valid 060215Z - 060415Z
Probability of Watch Issuance...40 percent
SUMMARY...Thunderstorms are expected to increase in coverage and
intensity this evening across North Dakota. Damaging wind gusts will
be the primary threat. A Severe Thunderstorm Watch may be needed
over the next few hours.
DISCUSSION...While convection has generally struggled over the past
several hours across portions of Montana, very steep low-level lapse
rates have allowed for occasional strong wind gusts even from
relatively unorganized thunderstorms (e.g., most notably a recent
measured 70 mph wind gust in Prairie County Montana). Forecast
guidance continues to suggest this area of convection will become
better organized as it overspreads greater buoyancy across North
Dakota (e.g., 1000-2000 J/kg MLCAPE) over the next few hours.
Additionally, thunderstorm coverage/intensity should also increase
as a southerly low-level jet develops through the evening.
Damaging wind gusts will be the primary threat from any multicell
cluster or bowing segment, as deeply-mixed boundary layers (per 00Z
regional RAOBs) promote efficient thunderstorm downdrafts. Large
hail will also be possible with the strongest updrafts or with any
storms that can remain semi-discrete given the 30-40 knots of
effective bulk shear.
While the need for a Severe Thunderstorm Watch remains unclear,
owing to uncertainty regarding overall coverage of severe winds,
trends will continue to be monitored for possible watch issuance
over the next few hours.
..Elliott/Thompson.. 06/06/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...BIS...UNR...BYZ...
LAT...LON 47290338 48020181 48530015 48689912 48379844 47249831
46679980 46220146 45870324 45890394 46420408 47290338SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 5, 9:21 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Billings, Bowman, Burleigh, Dunn, Foster and 16 more | 5 hr |
| Jun 5, 10:47 PM MDT | Mesoscale Discussion | SPC | Adams, Bowman, Dunn, Grant, Hettinger, McHenry and 8 more | 88 min |
| Jun 6, 12:22 AM MDT | Mesoscale Discussion | SPC | Benson, Burleigh, Cavalier, Eddy, Emmons, Foster and 14 more | 113 min |
| Jun 6, 12:39 AM MDT | Severe Thunderstorm Watch | SPC | Benson, Cavalier, Eddy, Grand Forks, Griggs, Nelson and 6 more | 3 hr |
| Jun 6, 1:52 AM MDT | Mesoscale Discussion | SPC | McLean, Oliver, Sheridan, Wells | 53 min |
Nearby
Mesoscale Discussions in North Dakota, 2021Every 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.