Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 131, NWS Twin Cities, MN

September 17, 20214 counties in Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 17, 2021, 3:30 AM CDT for 4 counties in Wisconsin. It was in force for 30 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 17, 2021, 3:30 AM CDT (08:30 UTC)
Expired: Sep 17, 2021, 4:00 AM CDT
In force: 30 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Barron County, WI, Dunn County, WI, Polk County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 107 km from the middle of the area, began a volume at 08:31 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.

What was reported inside it

Time	Report	Where	Remark
Sep 17, 3:34 AM CDT	TSTM WND DMG	4 W Roberts, WI	TWITTER PICTURE OF 1/2 TO 1 INCH TREE LIMBS DOWN. TIME ESTIMATED BY RADAR.
Sep 17, 3:37 AM CDT	TSTM WND DMG	4 W Roberts, WI	APPROXIMATELY 10 INCH DIAMETER TREE SNAPPED NEAR BASE. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 8.5 hours before the alert went out and 342 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1604 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 161 m²/s²
0-3 km storm-relative helicity: 285 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

049 
WUUS53 KMPX 170830
SVRMPX
WIC005-033-095-109-170900-
/O.NEW.KMPX.SV.W.0131.210917T0830Z-210917T0900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
330 AM CDT Fri Sep 17 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northwestern Dunn County in west central Wisconsin...
  St. Croix County in west central Wisconsin...
  Western Barron County in northwestern Wisconsin...
  Southeastern Polk County in northwestern Wisconsin...

* Until 400 AM CDT.

* At 330 AM CDT, severe thunderstorms were located along a line
  extending from near Dresser to near Hudson, moving northeast at 75
  mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Amery and Balsam Lake around 335 AM CDT.
  New Richmond and Baldwin around 340 AM CDT.
  Turtle Lake around 345 AM CDT.
  Glenwood City and Almena around 350 AM CDT.

Other locations in the path of these severe thunderstorms include
Cumberland, Prairie Farm and Ridgeland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.
 
&&

LAT...LON 4515 9175 4489 9277 4494 9275 4500 9278
      4538 9267 4564 9203 4564 9201
TIME...MOT...LOC 0830Z 241DEG 66KT 4534 9255 4497 9268 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

TDH

2 follow-up statements

748 
WWUS53 KMPX 170845
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
345 AM CDT Fri Sep 17 2021

WIC005-033-095-109-170900-
/O.CON.KMPX.SV.W.0131.000000T0000Z-210917T0900Z/
Dunn WI-St. Croix WI-Barron WI-Polk WI-
345 AM CDT Fri Sep 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 AM CDT
FOR NORTHWESTERN DUNN...NORTHEASTERN ST. CROIX...WESTERN BARRON AND
SOUTHEASTERN POLK COUNTIES...

At 345 AM CDT, severe thunderstorms were located along a line
extending from 7 miles northwest of Turtle Lake to 7 miles east of
New Richmond, moving east at 70 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Turtle Lake around 350 AM CDT.

Other locations in the path of these severe thunderstorms include
Cumberland and Almena.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4515 9175 4503 9254 4543 9254 4564 9203
      4564 9201
TIME...MOT...LOC 0845Z 270DEG 66KT 4545 9225 4509 9239 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

TDH

210 
WWUS53 KMPX 170856
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
356 AM CDT Fri Sep 17 2021

WIC005-033-095-109-170906-
/O.EXP.KMPX.SV.W.0131.000000T0000Z-210917T0900Z/
Dunn WI-St. Croix WI-Barron WI-Polk WI-
356 AM CDT Fri Sep 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN DUNN...
NORTHEASTERN ST. CROIX...WESTERN BARRON AND SOUTHEASTERN POLK
COUNTIES WILL EXPIRE AT 400 AM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

LAT...LON 4515 9175 4503 9254 4543 9254 4564 9203
      4564 9201
TIME...MOT...LOC 0856Z 241DEG 66KT 4545 9225 4509 9239 

$$

TDH

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 17, 3:15 AM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Polk, Saint Croix	15 min
Sep 17, 3:18 AM CDT	Special Weather Statement	MPX	Pierce	27 min
Sep 17, 4:00 AM CDT	Special Weather Statement	MPX	Barron	30 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.