Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1355
The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2021, 5:00 PM CDT for 15 counties in Minnesota; Douglas County, Wisconsin. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 26, 2021, 5:00 PM CDT (22:00 UTC)
- Expired
- Jul 26, 2021, 7:00 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...severe thunderstorm watch likely
- Chance of a watch
- 80%
Counties Aitkin County, MN, Beltrami County, MN, Carlton County, MN, Cass County, MN, Clearwater County, MN, Crow Wing County, MN, Hubbard County, MN, Itasca County, MN, Kanabec County, MN, Koochiching County, MN, Mille Lacs County, MN, Morrison County, MN, Pine County, MN, Saint Louis County, MN, Wadena County, MN, Douglas County, WI
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
International Fa, MN (KINL), launched 12:00Z, 10.0 hours before the alert went out and 141 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2151 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 86 m²/s²
- 0-3 km storm-relative helicity
- 234 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
756
ACUS11 KWNS 262201
SWOMCD
SPC MCD 262200
MNZ000-WIZ000-270000-
Mesoscale Discussion 1355
NWS Storm Prediction Center Norman OK
0500 PM CDT Mon Jul 26 2021
Areas affected...north-central and northeast Minnesota
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 262200Z - 270000Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorms capable of very large hail, gusty
thunderstorm winds, and a tornado or two will be possible across the
area this afternoon and evening. A watch will likely be needed for
portions of the area later today.
DISCUSSION...A cluster of thunderstorms persist across north-central
Minnesota this afternoon associated with modest warm-air advection
along a west-northwest to east-southeast warm-front draped across
northern Minnesota. Although temperatures have warmed into the
mid-to-upper-80s F along both sides of the warm front, surface
moisture, as measured by dewpoints, dramatically increases to the
south, rising from mid 50s F north to mid 60s F south. The result is
a strongly unstable airmass along and south of the warm front.
Strong deep-layer shear across the region will likely sustain
thunderstorm intensity and organization into he evening hours, with
supercell thunderstorms possible.
Warm-air advection is expected to continue through the evening
hours, even strengthening after 00Z. The result should be one or
more rounds of thunderstorms across the region. Given the degree of
instability and strong shear, very large hail and gusty thunderstorm
winds will be likely with any intense thunderstorm. Additionally,
the presence of a warm-front across the area will result in the
potential for a tornado or two with any surface-based or
near-surface-based supercell that interacts with the warm front.
A watch will likely be needed this afternoon or evening across
portions of the area.
..Marsh/Grams.. 07/26/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...MPX...FGF...
LAT...LON 47809584 48309571 48549430 48319312 47879203 47279165
46519166 45699292 46009468 47069564 47809584SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 25, 9:49 PM CDT | Mesoscale Discussion | SPC | Big Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 6 more | 116 min |
| Jul 26, 5:22 PM CDT | Severe Thunderstorm Watch | SPC | Aitkin, Becker, Beltrami, Big Stone, Carlton, Cass and 22 more | 5 hr |
| Jul 26, 4:31 PM CDT | Mesoscale Discussion | SPC | Brown, Calumet, Kewaunee, Manitowoc, Marinette, Menominee and 3 more | 89 min |
Nearby
Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in Wisconsin, 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.