Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 143, NWS Twin Cities, MN

December 15, 20214 counties in Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Dec 15, 2021, 8:31 PM CST for 4 counties in Wisconsin. It was in force for 44 min. 4 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: Dec 15, 2021, 8:31 PM CST (02:31 UTC)
Expired: Dec 15, 2021, 9:15 PM CST
In force: 44 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Chippewa County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI

The radar

The La Crosse radar (KARX), 116 km from the middle of the area, began a volume at 02:33 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
Dec 15, 8:50 PM CST	TSTM WND DMG	3 S Eau Claire, WI	REPORT OF MULTIPLE BRANCHES DOWN, HARD TO DETERMINE SIZE IN THE DARKNESS.
Dec 15, 8:58 PM CST	TORNADO	5 W Fairchild, WI	NWS DAMAGE SURVEY FOUND A PRELIMINARY EF-0 TORNADO TRACK OF APPROXIMATELY 6 MILES TO THE NORTHEAST IN SOUTHEAST EAU CLAIRE COUNTY.
Dec 15, 9:00 PM CST	TSTM WND GST 67	4 Nne Eau Claire, WI	OFFICIAL WIND GUST OBSERVATION FROM KEAU.
Dec 15, 9:02 PM CST	TORNADO	5 E Chippewa Falls, WI	THE TORNADO UPROOTED OR BROKE HUNDREDS OF TREES. MANY TREES LANDED ON HOUSES. SHINGLES WERE ALSO REMOVED FROM PORTIONS OF TWO ROOFS. SOFFITS WERE TORN AWAY FROM THREE HOUSES. PATH LENGTH, 5.5 MILES, WIDTH 75 YARDS, RATING EF0, PEAK WIND ESTIMATED NEAR 85 MPH.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Dec 15, 5:30 PM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.5 hours before the alert went out and 167 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: 633 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 770 m above ground
0-6 km bulk shear: 75 kt
0-1 km storm-relative helicity: 443 m²/s²
0-3 km storm-relative helicity: 470 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.7

Open this sounding in Storm Lab

The text

As transmitted.

137 
WUUS53 KMPX 160231
SVRMPX
WIC017-033-035-091-160315-
/O.NEW.KMPX.SV.W.0143.211216T0231Z-211216T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
831 PM CST Wed Dec 15 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northeastern Pepin County in west central Wisconsin...
  Southeastern Dunn County in west central Wisconsin...
  Southern Chippewa County in west central Wisconsin...
  Eau Claire County in west central Wisconsin...

* Until 915 PM CST.

* At 830 PM CST, severe thunderstorms were located along a line
  extending from near Eau Galle to 9 miles west of Independence to
  near Galesville, moving northeast at 65 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Menomonie around 845 PM CST.
  Elk Mound around 850 PM CST.

Other locations in the path of these severe thunderstorms include
Colfax, Augusta, Fall Creek, Bloomer and Boyd.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM CST for west central
Wisconsin.

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

A Tornado Watch remains in effect until 1100 PM CST for west central
Wisconsin.

&&

LAT...LON 4460 9182 4487 9198 4519 9164 4516 9126
      4488 9091 4460 9093
TIME...MOT...LOC 0230Z 224DEG 58KT 4471 9205 4438 9162 4406 9131 

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

$$

Dye

1 follow-up statement

989 
WWUS53 KMPX 160249
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
849 PM CST Wed Dec 15 2021

WIC091-160258-
/O.CAN.KMPX.SV.W.0143.000000T0000Z-211216T0315Z/
Pepin WI-
849 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PEPIN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 1100 PM CST for west central
Wisconsin.

LAT...LON 4460 9158 4465 9165 4468 9165 4468 9170
      4487 9198 4519 9164 4516 9126 4488 9091
      4460 9094
TIME...MOT...LOC 0248Z 224DEG 58KT 4492 9177 4459 9134 4427 9103 

$$

WIC017-033-035-160315-
/O.CON.KMPX.SV.W.0143.000000T0000Z-211216T0315Z/
Dunn WI-Chippewa WI-Eau Claire WI-
849 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CST
FOR SOUTHEASTERN DUNN...SOUTHERN CHIPPEWA AND EAU CLAIRE COUNTIES...

At 848 PM CST, severe thunderstorms were located along a line
extending from 5 miles northwest of Elk Mound to near Strum to 9
miles west of Black River Falls, moving northeast at 65 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
  Augusta, Fall Creek, Bloomer and Boyd.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM CST for west central
Wisconsin.

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

&&

LAT...LON 4460 9158 4465 9165 4468 9165 4468 9170
      4487 9198 4519 9164 4516 9126 4488 9091
      4460 9094
TIME...MOT...LOC 0248Z 224DEG 58KT 4492 9177 4459 9134 4427 9103 

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

$$

Dye

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 15, 8:09 PM CST	Severe Thunderstorm Warning	MPX	Dunn, Pepin, Pierce, Saint Croix	36 min
Dec 15, 8:17 PM CST	Tornado Warning	MPX	Dunn, Pepin	28 min
Dec 15, 9:10 PM CST	Severe Thunderstorm Warning	MPX	Chippewa, Rusk	28 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.