Alert archive / Wisconsin / Mesoscale Discussions in 2021
Mesoscale Discussion 1352
The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2021, 4:31 PM CDT for 9 counties in Wisconsin. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Jul 26, 2021, 4:31 PM CDT (21:31 UTC)
- Expired
- Jul 26, 2021, 6:00 PM CDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Brown County, WI, Calumet County, WI, Kewaunee County, WI, Manitowoc County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Outagamie County, WI, Shawano County, WI
The radar
The Green Bay radar (KGRB), 21 km from the middle of the area, began a volume at 21:31 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
Green Bay/Straub, WI (KGRB), launched 12:00Z, 9.5 hours before the alert went out and 22 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
- 2259 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 74 m²/s²
- 0-3 km storm-relative helicity
- 89 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
998
ACUS11 KWNS 262131
SWOMCD
SPC MCD 262131
WIZ000-MIZ000-262300-
Mesoscale Discussion 1352
NWS Storm Prediction Center Norman OK
0431 PM CDT Mon Jul 26 2021
Areas affected...Portions of northeast Wisconsin
Concerning...Severe potential...Watch unlikely
Valid 262131Z - 262300Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated severe storms may pose a large hail and damaging
wind threat over the next 1 to 2 hours.
DISCUSSION...Temperatures have warmed into the mid 80s with
dewpoints in the mid 60s across north central Wisconsin. This
destabilization has been sufficient to erode surface inhibition
according to SPC mesoanalysis with MLCAPE around 1500 J/kg. Flow is
less than 30kts in the lowest 5km, but strengthens to near 50 knots
above 8km per KGRB VWP. Given storm depth around 12km, and the
observations from the VWP, the effective shear is probably greater
than the 25 knots shown on SPC mesoanalysis. Stronger effective
shear would also explain the organization of the large supercell
north of Green Bay. This supercell currently shows MESH around 1.5
inches. This cell has turned right and may try to continue southward
along the instability gradient. However, expect this supercell to
eventually move eastward over Lake Michigan and into an airmass with
decreasing instability and increasing inhibition which should limit
storm intensity. Given the small temporal and areal threat from this
storm activity, no watch is anticipated, but some large hail and
damaging winds may be possible over the next 1 to 2 hours.
..Bentley/Grams.. 07/26/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...GRB...MKX...
LAT...LON 45698838 45478757 45258730 44958721 44488725 44238741
43798769 43838813 43978841 44148870 44428889 44798883
45698838SPC 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 | Douglas | 2 hr |
Nearby
Mesoscale 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.