Alert archive / Wisconsin / Special Weather Statements in 2021

Special Weather Statement, NWS Milwaukee, WI

April 7, 2021Waukesha County, Wisconsin

NWS Milwaukee, WI issued this special weather statement at Apr 7, 2021, 3:45 PM CDT for Waukesha County, Wisconsin. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 7, 2021, 3:45 PM CDT (20:45 UTC)
Expired
Apr 7, 2021, 4:15 PM CDT
In force
30 min
Issued by
NWS Milwaukee, WI

County Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 22 km from the middle of the area, began a volume at 20:45 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 8.8 hours before the alert went out and 175 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 2021-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2021-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1411 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

809 
WWUS83 KMKX 072045
SPSMKX

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
345 PM CDT Wed Apr 7 2021

WIZ065-070-071-072115-
Walworth-Waukesha-Racine-

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN WALWORTH...
NORTHWESTERN RACINE AND CENTRAL WAUKESHA COUNTIES...

At 344 PM CDT, a strong thunderstorm was located near Vernon, or near
Mukwonago, moving north at 30 mph.

Winds of 30 to 40 mph and pea size hail are possible with this storm.

Locations impacted include...
Waukesha, New Berlin, Brookfield, Muskego, Pewaukee, Hartland,
Mukwonago, Delafield, Elm Grove, Wales, Vernon, North Prairie, Big
Bend, Potter Lake, Waterford North, Nashotah, Waterville, Oconomowoc
Lake, Genesee Depot and Genesee.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4277 8826 4285 8844 4309 8845 4309 8807
TIME...MOT...LOC 2044Z 193DEG 21KT 4293 8831 

$$

WAGNER

The office that day

Everything else NWS Milwaukee, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 7, 2:50 PM CDTSpecial Weather StatementMKXWalworth25 min
Apr 7, 3:14 PM CDTSpecial Weather StatementMKXWaukesha46 min
Apr 7, 3:36 PM CDTSpecial Weather StatementMKXDodge24 min
Apr 7, 3:59 PM CDTSpecial Weather StatementMKXDodge, Fond du Lac, Washington, Waukesha61 min
Apr 7, 4:13 PM CDTSpecial Weather StatementMKXKenosha32 min
Apr 7, 4:40 PM CDTSpecial Weather StatementMKXKenosha, Milwaukee, Racine35 min

Nearby

Special Weather Statements in Wisconsin, 2021Every special weather statement 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.