Alert archive / Wisconsin / Mesoscale Discussions in 2026
Mesoscale Discussion 430
The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2026, 6:07 PM CDT for Jefferson County, Waukesha County, Wisconsin. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Apr 14, 2026, 6:07 PM CDT (23:07 UTC)
- Expired
- Apr 14, 2026, 7:00 PM CDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 109
Counties Jefferson County, WI, Waukesha County, WI
The radar
The Milwaukee radar (KMKX), 19 km from the middle of the area, began a volume at 23:11 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
Lincoln, IL (KILX), launched 12:00Z, 11.1 hours before the alert went out and 333 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
- 277 J/kg
- Mixed-layer CIN
- -96 J/kg
- Mixed-layer LCL
- 1325 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 316 m²/s²
- 0-3 km storm-relative helicity
- 312 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted.
056
ACUS11 KWNS 142307
SWOMCD
SPC MCD 142307
WIZ000-150000-
Mesoscale Discussion 0430
NWS Storm Prediction Center Norman OK
0607 PM CDT Tue Apr 14 2026
Areas affected...Southeast Wisconsin
Concerning...Tornado Watch 109...
Valid 142307Z - 150000Z
The severe weather threat for Tornado Watch 109 continues.
SUMMARY...The risk for tornadoes (possibly strong) and destructive
hail will continue with two supercells moving towards the Milwaukee
metro region.
DISCUSSION...Two supercells are tracking eastward toward Milwaukee
and nearby suburbs. These supercells have a history of producing
large to very-large hail in Madison. The KMKX VAD shows ample
low-level shear and near 50 kts of 0-6 km shear. With steep
mid-level lapse rates, large to very-large hail will remain
possible. The tornado threat is greatest with the lead supercell
with KMKX showing periodic increases in low-level
inflow/organization. Tornadoes, potentially strong, are also
possible.
..Wendt.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MKX...
LAT...LON 43078912 43328901 43408795 43178773 42988780 42978895
43078912
MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 INSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 13, 7:57 PM CDT | Mesoscale Discussion | SPC | Adams, Clark, Green Lake, Jackson, Juneau, Marquette and 4 more | 93 min |
| Apr 13, 9:15 PM CDT | Mesoscale Discussion | SPC | Adams, Columbia, Crawford, Dane, Dodge, Fond du Lac and 23 more | 60 min |
| Apr 13, 9:42 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Calumet, Columbia, Crawford, Dane and 31 more | 5 hr |
| Apr 13, 11:43 PM CDT | Mesoscale Discussion | SPC | Columbia, Dane, Dodge, Fond du Lac, Iowa, Jefferson and 5 more | 92 min |
| Apr 14, 1:50 AM CDT | Mesoscale Discussion | SPC | Kenosha, Milwaukee, Ozaukee, Racine | 85 min |
| Apr 14, 12:56 PM CDT | Mesoscale Discussion | SPC | Columbia, Crawford, Dane, Grant, Green, Iowa and 6 more | 2 hr |
| Apr 14, 2:33 PM CDT | Tornado Watch | SPC | Adams, Calumet, Columbia, Crawford, Dane, Dodge and 26 more | 9 hr |
| Apr 14, 3:42 PM CDT | Mesoscale Discussion | SPC | Grant, Iowa, Lafayette | 93 min |
| Apr 14, 6:36 PM CDT | Mesoscale Discussion | SPC | Dane, Grant, Green, Iowa, Lafayette, Rock | 114 min |
Nearby
Mesoscale Discussions in Wisconsin, 2026Every mesoscale discussion in 2026
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.