Alert archive / Wisconsin / Mesoscale Discussions in 2021
Mesoscale Discussion 1163
The Storm Prediction Center issued this mesoscale discussion at Jul 6, 2021, 1:44 PM CDT for 20 counties in Wisconsin. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Jul 6, 2021, 1:44 PM CDT (18:44 UTC)
- Expired
- Jul 6, 2021, 2:45 PM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 80%
Counties Brown County, WI, Calumet County, WI, Columbia County, WI, Dodge County, WI, Fond du Lac County, WI, Green Lake County, WI, Kewaunee County, WI, Manitowoc County, WI, Marquette County, WI, Menominee County, WI, Oconto County, WI, Outagamie County, WI, Ozaukee County, WI, Portage County, WI, Shawano County, WI, Sheboygan County, WI, Washington County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI
The radar
The Green Bay radar (KGRB), 55 km from the middle of the area, began a volume at 18:47 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, 6.7 hours before the alert went out and 53 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
- 34 J/kg
- Mixed-layer CIN
- -188 J/kg
- Mixed-layer LCL
- 1667 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 49 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
639
ACUS11 KWNS 061845
SWOMCD
SPC MCD 061844
WIZ000-061945-
Mesoscale Discussion 1163
NWS Storm Prediction Center Norman OK
0144 PM CDT Tue Jul 06 2021
Areas affected...eastern Wisconsin
Concerning...Severe potential...Watch likely
Valid 061844Z - 061945Z
Probability of Watch Issuance...80 percent
SUMMARY...Isolated severe thunderstorms are possible along a
stationary front this afternoon. Damaging wind gusts and large hail
are expected. A watch may be needed.
DISCUSSION...Several thunderstorms have recently developed along the
intersection of the lake breeze and stationary front across eastern
Wisconsin. A recent wind gust to 56 mph near Manitowoc suggests
these storms are beginning to intensify. Daytime heating over a
broken cloud deck has allowed surface temperatures to warm into the
low to mid 80s with surface dewpoints in the mid 60s F. 1500-2000
J/kg of MLCAPE will support robust updraft development within a
weak/moderately sheared environment of 30-40 kts effective shear
along the front. Organized clusters/short line segments and a few
supercells appear likely to evolve through the early afternoon.
Somewhat enhanced flow ahead of a weak MCV may support a locally
stronger vertical shear and the risk for a brief tornado with a
stronger supercell where flow surface flow is backed along the
stationary front. Given the increasing convective
coverage/intensity, a weather watch may be needed shortly.
..Lyons/Guyer.. 07/06/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GRB...MKX...ARX...
LAT...LON 43058788 43068893 43528958 44218969 44908929 45118859
45038794 44798743 44118742 43608741 43058788SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 1:06 PM CDT | Mesoscale Discussion | SPC | Buffalo, Dunn, Eau Claire, Jackson, La Crosse, Monroe and 4 more | 114 min |
| Jul 6, 2:01 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Buffalo, Calumet, Clark, Columbia and 27 more | 8 hr |
| Jul 6, 5:22 PM CDT | Mesoscale Discussion | SPC | Adams, Calumet, Columbia, Crawford, Dane, Dodge and 20 more | 113 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.