Alert archive / Wisconsin / Tornado Warnings in 2021

Tornado Warning 15, NWS Twin Cities, MN

July 28, 2021Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Jul 28, 2021, 9:55 PM CDT for Saint Croix County, Wisconsin. It was in force for 35 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: Jul 28, 2021, 9:55 PM CDT (02:55 UTC)
Expired: Jul 28, 2021, 10:30 PM CDT
In force: 35 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 94 km from the middle of the area, began a volume at 03:00 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 watch it was issued in

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

Issued	Product	Office	Lasted
Jul 28, 7:17 PM CDT	Severe Thunderstorm Watch PDS	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.9 hours before the alert went out and 97 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: 4815 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 1185 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 374 m²/s²
0-3 km storm-relative helicity: 461 m²/s²
Significant tornado parameter: 8.9
Supercell composite: 48.1

Open this sounding in Storm Lab

The text

As transmitted.

726 
WFUS53 KMPX 290255
TORMPX
WIC109-290330-
/O.NEW.KMPX.TO.W.0015.210729T0255Z-210729T0330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Twin Cities/Chanhassen MN
955 PM CDT Wed Jul 28 2021

The National Weather Service in the Twin Cities has issued a

* Tornado Warning for...
  Southeastern St. Croix County in west central Wisconsin...

* Until 1030 PM CDT.
    
* At 955 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Hammond, or 15 miles northeast of River Falls,
  moving southeast at 20 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur. Tree 
           damage is likely.

* This dangerous storm will be near...
  Hammond around 1005 PM CDT.
  Baldwin around 1010 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Woodville.

# 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4506 9249 4511 9239 4497 9220 4489 9240
TIME...MOT...LOC 0255Z 324DEG 17KT 4504 9242 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Dye

1 follow-up statement

168 
WWUS53 KMPX 290322
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1022 PM CDT Wed Jul 28 2021

WIC109-290332-
/O.EXP.KMPX.TO.W.0015.000000T0000Z-210729T0330Z/
St. Croix WI-
1022 PM CDT Wed Jul 28 2021

...THE TORNADO WARNING FOR SOUTHEASTERN ST. CROIX COUNTY WILL EXPIRE
AT 1030 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
west central Wisconsin.

LAT...LON 4506 9249 4511 9239 4497 9220 4489 9240
TIME...MOT...LOC 0322Z 324DEG 17KT 4494 9232 

$$

Dye

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 7:19 PM CDT	Special Weather Statement	MPX	Rusk	26 min
Jul 28, 7:37 PM CDT	Severe Thunderstorm Warning	MPX	Rusk	23 min
Jul 28, 7:43 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Polk, Rusk	32 min
Jul 28, 8:01 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Chippewa, Rusk	44 min
Jul 28, 8:09 PM CDT	Tornado Warning	MPX	Polk	35 min
Jul 28, 8:46 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Chippewa, Rusk	59 min
Jul 28, 8:55 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Polk	50 min
Jul 28, 9:08 PM CDT	Tornado Warning	MPX	Chippewa	37 min
Jul 28, 9:25 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Saint Croix	65 min
Jul 28, 9:30 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Eau Claire	60 min
Jul 28, 9:36 PM CDT	Tornado Warning	MPX	Saint Croix	24 min
Jul 28, 9:37 PM CDT	Severe Thunderstorm Warning	MPX	Saint Croix	38 min
Jul 28, 10:09 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Pepin, Pierce, Saint Croix	51 min
Jul 28, 10:18 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Eau Claire, Pepin	42 min
Jul 28, 10:21 PM CDT	Severe Thunderstorm Warning	MPX	Saint Croix	24 min
Jul 28, 10:36 PM CDT	Severe Thunderstorm Warning	MPX	Pepin	39 min
Jul 28, 10:57 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Pepin, Pierce	48 min

Nearby

Tornado Warnings in Wisconsin, 2021 Every tornado warning in 2021 Tornadoes 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.