Alert archive / Wisconsin / Mesoscale Discussions in 2021
Mesoscale Discussion 1443
The Storm Prediction Center issued this mesoscale discussion at Aug 8, 2021, 12:57 PM CDT for 28 counties in Wisconsin. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- Aug 8, 2021, 12:57 PM CDT (17:57 UTC)
- Expired
- Aug 8, 2021, 2:30 PM CDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 28 counties
Adams County, WI, Brown County, WI, Calumet County, WI, Columbia County, WI, Crawford County, WI, Dodge County, WI, Fond du Lac County, WI, Green Lake County, WI, Juneau County, WI, Kewaunee County, WI, La Crosse County, WI, Manitowoc County, WI, Marathon County, WI, Marquette County, WI, Monroe County, WI, Outagamie County, WI, Ozaukee County, WI, Portage County, WI, Richland County, WI, Sauk County, WI, Shawano County, WI, Sheboygan County, WI, Vernon County, WI, Washington County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI
The radar
The Milwaukee radar (KMKX), 116 km from the middle of the area, began a volume at 17:57 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, 6.0 hours before the alert went out and 126 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
- 445 J/kg
- Mixed-layer CIN
- -23 J/kg
- Mixed-layer LCL
- 568 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 108 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
561
ACUS11 KWNS 081758
SWOMCD
SPC MCD 081757
WIZ000-IAZ000-081930-
Mesoscale Discussion 1443
NWS Storm Prediction Center Norman OK
1257 PM CDT Sun Aug 08 2021
Areas affected...Portions of southern and central Wisconsin.
Concerning...Severe potential...Watch possible
Valid 081757Z - 081930Z
Probability of Watch Issuance...60 percent
SUMMARY...The severe weather potential is expected to increase
through the afternoon.
DISCUSSION...An MCV can be seen on visible satellite and
intermittently in surface wind observations in far southeast
Minnesota at 18Z. This feature is will continue to lift northeast
through the day. Extending east from this MCV is a warm front from
near the MN/IA/WI border to just south of Green Bay. This warm front
is expected to lift north through the afternoon with the MCV. SPC
mesoanalysis suggests areas across southern Wisconsin have
destabilized (~1500 J/kg MLCAPE) with surface based inhibition
mostly eroded. Consequently, visible satellite now shows surface
based cumulus development east of the MCV from western Wisconsin
into eastern Iowa and western Illinois. Therefore, anticipate storm
development within the next 1 to 2 hours across portions of
southwest Wisconsin. Area VWPs have sampled around 50 knots of flow
around 6 km which should provide ample shear for some storm
organization including some embedded supercell structures. The
primary hazards are expected to be damaging winds and severe hail,
but a tornado or two cannot be ruled out in close proximity to the
warm front where low-level vorticity should be enhanced. A watch is
possible within the next 1 to 2 hours once increasing storm
coverage/intensity appears imminent.
..Bentley/Thompson.. 08/08/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GRB...MKX...ARX...
LAT...LON 43998759 43268771 43288955 43179067 43129118 43649122
44009112 44998998 44758726 43998759SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 1:59 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Calumet, Clark, Columbia, Dodge and 20 more | 6 hr |
| Aug 8, 3:53 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calumet, Clark, Columbia, Dodge and 22 more | 97 min |
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.