Alert archive / Wisconsin / Mesoscale Discussions in 2022

Mesoscale Discussion 708

May 10, 202232 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 10, 2022, 12:45 PM CDT for 32 counties in Wisconsin. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
May 10, 2022, 12:45 PM CDT (17:45 UTC)
Expired
May 10, 2022, 3:15 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
80%
All 32 counties

Adams County, WI, Brown County, WI, Calumet County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Grant County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, La Crosse County, WI, Langlade County, WI, Marathon County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oconto County, WI, Outagamie County, WI, Portage County, WI, Richland County, WI, Sauk County, WI, Shawano County, WI, Vernon County, WI, Washington County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 120 km from the middle of the area, began a volume at 17:46 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 5.8 hours before the alert went out and 145 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-pSkew-T log-p diagram, Green Bay/Straub, WI at 12:00Z on 2022-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 495 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 12:00Z on 2022-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
495 J/kg
Mixed-layer CIN
-361 J/kg
Mixed-layer LCL
875 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

208 
ACUS11 KWNS 101745
SWOMCD
SPC MCD 101745 
WIZ000-IAZ000-MNZ000-102015-

Mesoscale Discussion 0708
NWS Storm Prediction Center Norman OK
1245 PM CDT Tue May 10 2022

Areas affected...Parts of far northeast Iowa into central and
southern Wisconsin

Concerning...Severe potential...Watch likely 

Valid 101745Z - 102015Z

Probability of Watch Issuance...80 percent

SUMMARY...The risk of widely scattered thunderstorms capable of
large to very large hail, damaging gusts, and a couple tornadoes
will increase between 19Z-21Z. A watch will likely be needed for
parts of the area this afternoon.

DISCUSSION...Latest surface analysis shows a
northeast/southwest-oriented quasi-stationary baroclinic zone
extending across central WI. Along and south of the boundary, strong
diurnal heating of an increasingly moist boundary layer (upper
60s/lower 70s surface dewpoints) beneath steep midlevel lapse rates
is contributing to a strongly unstable airmass. While southerly
surface winds will generally be weak across the warm sector, the
eventual development of a weak frontal wave along the boundary could
support subtle warm advection and slightly backed surface flow
across the warm sector. 

Despite negligible large-scale ascent characterized by neutral to
slight midlevel height rises across the area, water vapor imagery
shows a belt of strong west-southwesterly flow aloft -- supporting
30-45 kt of effective shear amid the destabilizing airmass. Isolated
to widely scattered thunderstorms should develop along the
baroclinic zone and spread east-northeastward this afternoon.
Initially, discrete to semi-discrete supercell structures will be
capable of isolated large to very large hail and damaging wind
gusts, though small, clockwise-turning low-level hodographs could
support a tornado or two with the more organized/discrete
supercells. With time, storms should gradually grow upscale with
eastward extent amid minimal CINH, when damaging winds and sporadic
large hail will be the primary concerns. A watch will likely be
needed this afternoon.

..Weinman/Mosier.. 05/10/2022

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

ATTN...WFO...GRB...MKX...DVN...ARX...

LAT...LON   43699125 44269094 44999018 45278965 45468866 45298818
            44638798 44078795 43288820 42988858 42818899 42709004
            42659077 42749114 43259139 43699125

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 7:48 PM CDTMesoscale DiscussionSPCBuffalo, Chippewa, Clark, Dunn, Eau Claire, Jackson and 10 more87 min
May 9, 8:17 PM CDTSevere Thunderstorm WatchSPCClark, Crawford, Jackson, La Crosse, Monroe, Richland and 2 more5 hr
May 9, 9:05 PM CDTMesoscale DiscussionSPCCrawford, Richland85 min
May 9, 11:07 PM CDTMesoscale DiscussionSPCAdams, Crawford, Grant, Iowa, Juneau, Marquette and 6 more113 min
May 10, 2:19 PM CDTTornado WatchSPCAdams, Brown, Calumet, Clark, Columbia, Crawford and 37 more7 hr
May 10, 6:45 PM CDTMesoscale DiscussionSPCAdams, Brown, Calumet, Clark, Columbia, Dodge and 24 more90 min

Nearby

Mesoscale Discussions in Wisconsin, 2022Every mesoscale discussion in 2022

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.