Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1150
The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2021, 6:31 PM CDT for 11 counties in Minnesota; 7 counties in Wisconsin. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Jul 4, 2021, 6:31 PM CDT (23:31 UTC)
- Expired
- Jul 4, 2021, 8:00 PM CDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 40%
Counties Aitkin County, MN, Carlton County, MN, Cass County, MN, Cook County, MN, Crow Wing County, MN, Itasca County, MN, Kanabec County, MN, Koochiching County, MN, Lake County, MN, Pine County, MN, Saint Louis County, MN, Ashland County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Iron County, WI, Sawyer County, WI, Washburn County, WI
The radar
The Duluth radar (KDLH), 11 km from the middle of the area, began a volume at 23:31 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
International Fa, MN (KINL), launched 12:00Z, 11.5 hours before the alert went out and 201 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
- 324 J/kg
- Mixed-layer CIN
- -193 J/kg
- Mixed-layer LCL
- 1044 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 251 m²/s²
- 0-3 km storm-relative helicity
- 271 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 4.6
The text
As transmitted.
267
ACUS11 KWNS 042331
SWOMCD
SPC MCD 042331
MIZ000-MNZ000-WIZ000-050100-
Mesoscale Discussion 1150
NWS Storm Prediction Center Norman OK
0631 PM CDT Sun Jul 04 2021
Areas affected...North-Central Minnesota and far Northwest Wisconsin
Concerning...Severe potential...Watch possible
Valid 042331Z - 050100Z
Probability of Watch Issuance...40 percent
SUMMARY...Isolated convective development may increase in coverage,
posing a hail/wind threat. Watch possible.
DISCUSSION...Regional satellite shows a developing area of cumulus
from near International Falls, MN, southward into north-central
portions of Minnesota. This convective development is occurring
along a surface trough, with a concentrated area of dew point
temperatures at or near 70 F. RAP soundings indicate the presence of
a weak cap that is likely being breached by the zone of enhanced
low-level moisture along with weak ascent aloft from an approaching
mid-level short-wave trough. The broader ambient environment is
characterized by MLCAPE near 2500 J/kg and modest effective shear
near 20 kt.
There remains considerable uncertainty on storm coverage and
intensity in the next few hours. Short-term convection-allowing
guidance suggests storms coverage may remain mostly isolated.
However, if the aforementioned observational trends continue, the
environment should be supportive of organized convection, favoring
multicells, with a hail/wind threat. Thus, watch issuance remains
possible at this time pending short-term convective trends that will
continue to be monitored.
..Karstens/Hart.. 07/04/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...DLH...MPX...FGF...
LAT...LON 45829279 46249451 47669466 48529382 48199166 47628969
46389005 45639118 45829279Nearby
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; radar from the NEXRAD Level II archive.