Alert archive / Wisconsin / Special Weather Statements in 2021

Special Weather Statement, NWS Milwaukee, WI

September 13, 20214 counties in Wisconsin

NWS Milwaukee, WI issued this special weather statement at Sep 13, 2021, 8:21 AM CDT for 4 counties in Wisconsin. It was in force for 39 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
Sep 13, 2021, 8:21 AM CDT (13:21 UTC)
Expired
Sep 13, 2021, 9:00 AM CDT
In force
39 min
Issued by
NWS Milwaukee, WI
Hail
0.75 in
Wind
30

Counties Milwaukee County, WI, Ozaukee County, WI, Washington County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 47 km from the middle of the area, began a volume at 13:24 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, 1.4 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 2021-09-13Temperature 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°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 2021-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.1939587897Sfc1 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
921 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

627 
WWUS83 KMKX 131321
SPSMKX

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
821 AM CDT Mon Sep 13 2021
 
WIZ059-060-065-066-131400-
Waukesha WI-Milwaukee WI-Washington WI-Ozaukee WI-
821 AM CDT Mon Sep 13 2021

...A strong thunderstorm will impact portions of Ozaukee, Milwaukee,
Waukesha and Washington Counties through 900 AM CDT...

At 820 AM CDT, Doppler radar was tracking a strong thunderstorm over
Hartland, moving east at 40 mph.

HAZARD...Winds in excess of 30 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Milwaukee, Waukesha, West Allis, Wauwatosa, New Berlin, Brookfield,
Greenfield, Menomonee Falls, Oak Creek, West Bend, Muskego, Mequon,
South Milwaukee, Cudahy, Hartford, Whitefish Bay, Greendale,
Pewaukee, Brown Deer and Grafton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4338 8787 4326 8791 4318 8788 4312 8790
      4307 8787 4302 8790 4296 8785 4288 8785
      4285 8782 4284 8854 4315 8854 4320 8853
      4320 8842 4354 8840 4354 8780 4349 8779
TIME...MOT...LOC 1320Z 262DEG 39KT 4311 8835 

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

$$

MRC

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 1:41 AM CDTSpecial Weather StatementMKXDane, Iowa34 min
Sep 13, 1:55 AM CDTSevere Thunderstorm WarningMKXDane, Jefferson50 min
Sep 13, 2:15 AM CDTSevere Thunderstorm WarningMKXDane, Iowa45 min
Sep 13, 2:38 AM CDTSevere Thunderstorm WarningMKXJefferson, Waukesha52 min
Sep 13, 2:45 AM CDTSevere Thunderstorm WarningMKXDane30 min
Sep 13, 3:15 AM CDTSpecial Weather StatementMKXJefferson30 min
Sep 13, 3:29 AM CDTSpecial Weather StatementMKXWaukesha31 min
Sep 13, 3:34 AM CDTSevere Thunderstorm WarningMKXMilwaukee, Waukesha41 min
Sep 13, 3:38 AM CDTSpecial Marine WarningMKX75 min
Sep 13, 6:11 AM CDTSevere Thunderstorm WarningMKXIowa, Sauk28 min
Sep 13, 7:43 AM CDTSpecial Weather StatementMKXJefferson32 min
Sep 13, 1:13 PM CDTSmall Craft AdvisoryMKX29 hr
Sep 13, 3:51 PM CDTSpecial Weather StatementMKXDodge39 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.