Alert archive / Wisconsin / Mesoscale Discussions in 2021

Mesoscale Discussion 1078

June 24, 20216 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jun 24, 2021, 3:03 PM CDT for 6 counties in Wisconsin. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: Jun 24, 2021, 3:03 PM CDT (20:03 UTC)
Expired: Jun 24, 2021, 4:30 PM CDT
In force: 87 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

Counties Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Taylor County, WI

The radar

The La Crosse radar (KARX), 120 km from the middle of the area, began a volume at 20:04 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

Minneapolis, MN (KMPX), launched 12:00Z, 8.1 hours before the alert went out and 195 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1586 J/kg
Mixed-layer CIN: -257 J/kg
Mixed-layer LCL: 1372 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 216 m²/s²
0-3 km storm-relative helicity: 126 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

492 
ACUS11 KWNS 242003
SWOMCD
SPC MCD 242003 
WIZ000-242130-

Mesoscale Discussion 1078
NWS Storm Prediction Center Norman OK
0303 PM CDT Thu Jun 24 2021

Areas affected...northwest and north-central WI

Concerning...Severe potential...Watch possible 

Valid 242003Z - 242130Z

Probability of Watch Issuance...40 percent

SUMMARY...Storms will likely continue to develop over the next 1-2
hours along the front.  The stronger storms will be capable of a
risk for large hail and isolated damaging gusts.

DISCUSSION...Visible-satellite imagery shows convection developing
on the cold front over northwest WI.  Considerable cloudiness has
limited heating over southern WI and much of central WI where
temperatures are in the 60s to lower 70s deg F.  However, cloud
breaks over west-central WI has led to temperatures warming into the
upper 70s over north-central WI to the upper 80s near La Crosse.

Forecast soundings over northwest into north-central WI show
moderate buoyancy with adequate deep-layer shear for organized
storms.  Several stronger storms will likely be capable of at least
some risk for large hail and damaging gusts.  As this activity moves
east this evening into northeast WI, the combination of the loss of
heating and a cooler boundary layer, will probably result in storms
weakening by mid evening.

..Smith/Hart.. 06/24/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GRB...DLH...ARX...MPX...

LAT...LON   45249179 45509079 45308998 44718994 44399036 44349124
            44569197 44809223 45249179

Nearby

Mesoscale Discussions in Wisconsin, 2021 Every 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.