Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1349
The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2021, 9:49 PM CDT for 12 counties in Minnesota; Ransom County, Richland County, Sargent County, North Dakota; Grant County, Marshall County, Roberts County, South Dakota. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Jul 25, 2021, 9:49 PM CDT (02:49 UTC)
- Expired
- Jul 25, 2021, 11:45 PM CDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Big Stone County, MN, Chippewa County, MN, Douglas County, MN, Grant County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Otter Tail County, MN, Pope County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Wilkin County, MN, Ransom County, ND, Richland County, ND, Sargent County, ND, Grant County, SD, Marshall County, SD, Roberts County, SD
The radar
The Aberdeen radar (KABR), 158 km from the middle of the area, began a volume at 02:52 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 nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 2.8 hours before the alert went out and 181 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
- 1771 J/kg
- Mixed-layer CIN
- -59 J/kg
- Mixed-layer LCL
- 2015 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 114 m²/s²
- 0-3 km storm-relative helicity
- 380 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 31.3
The text
As transmitted.
478
ACUS11 KWNS 260249
SWOMCD
SPC MCD 260249
MNZ000-SDZ000-NDZ000-260445-
Mesoscale Discussion 1349
NWS Storm Prediction Center Norman OK
0949 PM CDT Sun Jul 25 2021
Areas affected...southeast North Dakota...northeast South
Dakota...and western Minnesota
Concerning...Severe potential...Watch unlikely
Valid 260249Z - 260445Z
Probability of Watch Issuance...5 percent
SUMMARY...Thunderstorms should continue to increase in coverage this
evening. Isolated large hail and gusty thunderstorm winds will be
possible -- especially with initial development. Given the
isolated/disorganized nature of any severe threat, a watch is
currently not expected, but conditions will continue to be
monitored.
DISCUSSION...Showers and thunderstorms will continue to develop and
expand in coverage this evening into the overnight hours across
portions of southeast North Dakota, northeast South Dakota, and
western Minnesota. These thunderstorms are developing on the nose of
modest warm-air advection between 850 and 700 millibars. This
airmass being advected in remains largely unstable, with
most-unstable CAPE values between 1500-2500 J/kg across
north-central South Dakota. Although deep-layer shear is between 35
and 40 knots, effective-layer shear remains poor -- largely
remaining less than 20 knots. Given the degree of instability and
mid-level lapse rates around 8 C/km, isolated large hail and gusty
thunderstorm winds may occur with initial updraft pulses. However,
the lack of effective-layer shear should hinder thunderstorm
organization, and increasing thunderstorms coverage should result in
destructive interference to support a sustained/organized severe
weather threat. As such a watch is currently not anticipated, but
conditions will continue to be monitored.
..Marsh/Grams.. 07/26/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FGF...ABR...
LAT...LON 45999764 46529769 46819682 46369530 45659464 44889463
44579537 45019685 45619761 45999764SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 5:00 PM CDT | Mesoscale Discussion | SPC | Aitkin, Beltrami, Carlton, Cass, Clearwater, Crow Wing and 9 more | 2 hr |
| Jul 26, 5:22 PM CDT | Severe Thunderstorm Watch | SPC | Aitkin, Becker, Beltrami, Big Stone, Carlton, Cass and 22 more | 5 hr |
| Jul 26, 4:42 PM CDT | Mesoscale Discussion | SPC | Barnes, Burleigh, Cass, Dickey, Emmons, Foster and 9 more | 2 hr |
Nearby
Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in North Dakota, 2021Mesoscale Discussions in South 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.