Alert archive / North Dakota / Mesoscale Discussions in 2018
Mesoscale Discussion 920
The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 1:06 PM CDT for 14 counties in North Dakota. It was in force for 114 min.
The area
The outline as issued.
The facts
- Issued
- Jun 28, 2018, 1:06 PM CDT (18:06 UTC)
- Expired
- Jun 28, 2018, 3:00 PM CDT
- In force
- 114 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
Counties Benson County, ND, Burleigh County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, McLean County, ND, Mercer County, ND, Nelson County, ND, Oliver County, ND, Sheridan County, ND, Steele County, ND, Traill County, ND, Wells County, ND
The radar
The Bismarck radar (KBIS), 108 km from the middle of the area, began a volume at 18:09 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 12:00Z, 6.1 hours before the alert went out and 106 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
- 1855 J/kg
- Mixed-layer CIN
- -101 J/kg
- Mixed-layer LCL
- 945 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 90 m²/s²
- 0-3 km storm-relative helicity
- 86 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.1
The text
As transmitted.
427
ACUS11 KWNS 281806
SWOMCD
SPC MCD 281806
NDZ000-282000-
Mesoscale Discussion 0920
NWS Storm Prediction Center Norman OK
0106 PM CDT Thu Jun 28 2018
Areas affected...Central North Dakota
Concerning...Severe potential...Watch likely
Valid 281806Z - 282000Z
Probability of Watch Issuance...80 percent
SUMMARY...A few supercells are expected to form this afternoon with
large hail, damaging winds, and a few tornadoes possible.
DISCUSSION...A cu field north of Bismark has shown some deeper
growth on GOES-16 1 minute mesosector. Modifying the 12Z Bismark
sounding for 17Z surface conditions (86/70 at KHZE) yields a nearly
uncapped mixed-layer parcel. Despite weak subsidence from building
heights aloft, and warming 700mb temps due to an advecting EML,
expect a few storms to develop in the next hour or two. With 50 to
60 knots of effective shear and SBCAPE of 5000 J/kg south of this
boundary, storms will quickly evolve into supercells. In addition,
already steep mid-level lapse rates will continue to steepen through
the afternoon. This kinematic and thermodynamic environment will be
supportive of very large hail and damaging winds. In addition,
backed surface winds and a veering wind profile between the surface
and 3 km will support a few tornadoes, however, limited speed shear
will be the primary limiting factor for a more significant tornado
threat this afternoon. A watch is likely in the next hour or two.
..Bentley/Hart.. 06/28/2018
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...BIS...
LAT...LON 47520270 47790259 47970225 48140127 48259981 48249918
48139829 47939743 47619713 47359701 47159729 47089834
47079950 46960047 47010120 47180233 47520270SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 28, 3:52 AM CDT | Mesoscale Discussion | SPC | Barnes, Burleigh, Cass, Dickey, Emmons, Foster and 12 more | 83 min |
| Jun 28, 7:40 AM CDT | Mesoscale Discussion | SPC | Adams, Barnes, Burleigh, Cass, Dickey, Emmons and 18 more | 3 hr |
| Jun 28, 1:33 PM CDT | Severe Thunderstorm Watch | SPC | Cass, Grand Forks, Steele, Traill | 6 hr |
| Jun 28, 3:16 PM CDT | Tornado Watch | SPC | Adams, Barnes, Benson, Billings, Bowman, Burleigh and 31 more | 8 hr |
| Jun 28, 3:35 PM CDT | Mesoscale Discussion | SPC | Billings, Bowman, Golden Valley, McKenzie, Slope | 2 hr |
| Jun 28, 3:53 PM CDT | Mesoscale Discussion | SPC | Cass, Grand Forks, Steele, Traill | 97 min |
| Jun 28, 5:23 PM CDT | Mesoscale Discussion | SPC | Grand Forks, Traill | 97 min |
| Jun 28, 6:59 PM CDT | Mesoscale Discussion | SPC | Adams, Benson, Billings, Bowman, Burleigh, Dunn and 22 more | 91 min |
Nearby
Mesoscale Discussions in North Dakota, 2018Every mesoscale discussion in 2018
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.