Alert archive / Wisconsin / Mesoscale Discussions in 2021

Mesoscale Discussion 1360

July 26, 2021Gogebic County, Michigan; Carlton County, Pine County, Minnesota; 12 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2021, 8:41 PM CDT for Gogebic County, Michigan; Carlton County, Pine County, Minnesota; 12 counties in Wisconsin. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Jul 26, 2021, 8:41 PM CDT (01:41 UTC)
Expired: Jul 26, 2021, 10:15 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 393...394

Counties Gogebic County, MI, Carlton County, MN, Pine County, MN, Ashland County, WI, Barron County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Iron County, WI, Oneida County, WI, Price County, WI, Rusk County, WI, Sawyer County, WI, Vilas County, WI, Washburn County, WI

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.7 hours before the alert went out and 263 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: 1670 J/kg
Mixed-layer CIN: -151 J/kg
Mixed-layer LCL: 1398 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 146 m²/s²
0-3 km storm-relative helicity: 187 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 5.9

Open this sounding in Storm Lab

The text

As transmitted.

446 
ACUS11 KWNS 270142
SWOMCD
SPC MCD 270141 
MIZ000-WIZ000-MNZ000-270315-

Mesoscale Discussion 1360
NWS Storm Prediction Center Norman OK
0841 PM CDT Mon Jul 26 2021

Areas affected...East-central MN...Northwest WI...Western Upper MI

Concerning...Severe Thunderstorm Watch 393...394...

Valid 270141Z - 270315Z

The severe weather threat for Severe Thunderstorm Watch 393, 394
continues.

SUMMARY...The threat for hail and damaging wind continues with
ongoing thunderstorm cluster. Watch issuance downstream is possible
by 02-03Z if the short-term intensity of this cluster is maintained.

DISCUSSION...At 0130Z, a long-lived thunderstorm cluster is
approaching northwest WI from northeast MN. While MLCINH will
increase with time across the region, the intensity of this cluster
may be maintained into a larger portion of northwest WI, where
somewhat stronger heating occurred earlier in the day and the
environment may still support near-surface-based updrafts for
another 2-3 hours. Even if the system becomes somewhat elevated,
MUCAPE in excess of 1500 J/kg and effective shear of 40+ kt will
continue to favor organized storm structures through the evening. 

Recent radar trends indicate that the cluster is taking on more of a
linear mode as the system accelerates southeastward. As a result,
the primary threat may be transitioning to damaging wind, though
some hail remains possible with the strongest embedded cores. New
watch issuance downstream is possible by 02-03Z if the short-term
intensity of the cluster is maintained this evening.

..Dean/Grams.. 07/27/2021

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

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

LAT...LON   46789311 46899175 46959037 46979017 46788936 46548900
            46198905 45478953 45249079 45379200 45859306 46789311

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 26, 11:50 PM CDT	Mesoscale Discussion	SPC	Antrim, Benzie, Charlevoix, Delta, Emmet, Grand Traverse and 5 more	55 min
Jul 26, 7:12 PM CDT	Mesoscale Discussion	SPC	Aitkin, Carlton, Cass, Crow Wing, Kanabec, Mille Lacs and 1 more	93 min
Jul 26, 7:40 PM CDT	Mesoscale Discussion	SPC	Becker, Big Stone, Clay, Douglas, Grant, Otter Tail and 6 more	95 min
Jul 27, 4:00 AM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Carver, Chisago, Dakota, Hennepin and 11 more	3 hr
Jul 27, 7:48 AM CDT	Mesoscale Discussion	SPC	Houston	117 min
Jul 26, 7:25 PM CDT	Severe Thunderstorm Watch	SPC	Ashland, Bayfield, Burnett, Douglas, Iron, Price and 2 more	3 hr

Nearby

Mesoscale Discussions in Wisconsin, 2021 Mesoscale Discussions in Minnesota, 2021 Mesoscale Discussions in Michigan, 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.