Alert archive / Wisconsin / Tornado Warnings in 2020

Tornado Warning 19, NWS Twin Cities, MN

July 18, 2020Washington County, Minnesota; Pierce County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Jul 18, 2020, 9:53 PM CDT for Washington County, Minnesota; Pierce County, Saint Croix County, Wisconsin. It was in force for 37 min. 3 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: Jul 18, 2020, 9:53 PM CDT (02:53 UTC)
Expired: Jul 18, 2020, 10:30 PM CDT
In force: 37 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Washington County, MN, Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 63 km from the middle of the area, began a volume at 02:57 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
Jul 18, 9:53 PM CDT	TORNADO	5 N Hastings, MN	AN EF1 TORNADO SPUN UP 5 MILES NORTH OF HASTINGS, MN. EXTENSIVE TREE DAMAGE ALONG THE PATH, MANY OF WHICH WERE SNAPPED ABOUT HALF WAY UP. THE HEAVIEST DAMAGE OCCURRED ON TOP OF A BLUFF AS THE TORNADO CROSSED THE ST. CROIX RIVER INTO WISCONSIN. A FEW FARM OUTBU
Jul 18, 9:54 PM CDT	TORNADO	5 N Hastings, MN	TORNADO DEBRIS SIGNATURE ON RADAR. MSP TDWR SAMPLED THE VORTEX WELL.
Jul 18, 10:07 PM CDT	TORNADO	5 Nne Prescott, WI	LARGE TREES DOWN ON ROADWAY. RADAR CONFIRMED TORNADO.

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
Jul 18, 3:53 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.9 hours before the alert went out and 66 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: 3128 J/kg
Mixed-layer CIN: -138 J/kg
Mixed-layer LCL: 1246 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 6.5

Open this sounding in Storm Lab

The text

As transmitted.

197 
WFUS53 KMPX 190253
TORMPX
MNC163-WIC093-109-190330-
/O.NEW.KMPX.TO.W.0019.200719T0253Z-200719T0330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Twin Cities/Chanhassen MN
953 PM CDT Sat Jul 18 2020

The National Weather Service in The Twin Cities has issued a

* Tornado Warning for...
  Southeastern Washington County in east central Minnesota...
  Northwestern Pierce County in west central Wisconsin...
  Southern St. Croix County in west central Wisconsin...

* Until 1030 PM CDT.
    
* At 953 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Cottage Grove, or 11 miles west of River Falls,
  moving east at 20 mph.

  HAZARD...Tornado.

  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...
  River Falls around 1030 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Kinnickinnic State Park and Afton State Park.

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 4480 9288 4484 9288 4492 9261 4476 9260
TIME...MOT...LOC 0253Z 263DEG 17KT 4482 9285 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

BORGHOFF

4 follow-up statements

086 
WWUS53 KMPX 190257
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
957 PM CDT Sat Jul 18 2020

MNC163-WIC093-109-190330-
/O.CON.KMPX.TO.W.0019.000000T0000Z-200719T0330Z/
Washington MN-Pierce WI-St. Croix WI-
957 PM CDT Sat Jul 18 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1030 PM CDT FOR
SOUTHEASTERN WASHINGTON...NORTHWESTERN PIERCE AND SOUTHERN ST. CROIX
COUNTIES...
        
At 956 PM CDT, a confirmed tornado was located near Prescott, or 10
miles west of River Falls, moving east at 25 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

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 tornado will be near...
  River Falls around 1025 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Kinnickinnic State Park and Afton State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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 4480 9288 4484 9288 4492 9261 4476 9260
TIME...MOT...LOC 0256Z 268DEG 20KT 4482 9281 

TORNADO...OBSERVED
HAIL...<.75IN

$$

BORGHOFF

785 
WWUS53 KMPX 190307
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1007 PM CDT Sat Jul 18 2020

MNC163-WIC109-190317-
/O.CAN.KMPX.TO.W.0019.000000T0000Z-200719T0330Z/
Washington MN-St. Croix WI-
1007 PM CDT Sat Jul 18 2020

...THE TORNADO WARNING FOR SOUTHEASTERN WASHINGTON AND SOUTHERN ST.
CROIX COUNTIES IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

LAT...LON 4480 9276 4484 9276 4486 9264 4486 9261
      4477 9261
TIME...MOT...LOC 0307Z 263DEG 19KT 4482 9274 

$$

WIC093-190330-
/O.CON.KMPX.TO.W.0019.000000T0000Z-200719T0330Z/
Pierce WI-
1007 PM CDT Sat Jul 18 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1030 PM CDT FOR
NORTHWESTERN PIERCE COUNTY...
        
At 1007 PM CDT, a confirmed tornado was located near Prescott, or
near River Falls, moving east at 20 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

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 tornado will be near...
  River Falls around 1030 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Kinnickinnic State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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 4480 9276 4484 9276 4486 9264 4486 9261
      4477 9261
TIME...MOT...LOC 0307Z 263DEG 19KT 4482 9274 

TORNADO...OBSERVED
HAIL...<.75IN

$$

BORGHOFF

096 
WWUS53 KMPX 190319
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1019 PM CDT Sat Jul 18 2020

WIC093-190330-
/O.CON.KMPX.TO.W.0019.000000T0000Z-200719T0330Z/
Pierce WI-
1019 PM CDT Sat Jul 18 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1030 PM CDT FOR
NORTHWESTERN PIERCE COUNTY...
    
At 1018 PM CDT, a severe thunderstorm capable of producing a tornado
was located near River Falls, moving east at 20 mph.

HAZARD...Tornado.

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...
  River Falls around 1030 PM CDT.

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 4481 9269 4485 9269 4486 9264 4486 9261
      4479 9261
TIME...MOT...LOC 0318Z 262DEG 19KT 4483 9266 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

BORGHOFF

557 
WWUS53 KMPX 190324
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1024 PM CDT Sat Jul 18 2020

WIC093-190333-
/O.EXP.KMPX.TO.W.0019.000000T0000Z-200719T0330Z/
Pierce WI-
1024 PM CDT Sat Jul 18 2020

...THE TORNADO WARNING FOR NORTHWESTERN PIERCE COUNTY WILL EXPIRE AT
1030 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
The Twin Cities.

LAT...LON 4481 9269 4485 9269 4486 9264 4486 9261
      4479 9261
TIME...MOT...LOC 0323Z 263DEG 17KT 4483 9264 

$$

BORGHOFF

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 7:07 PM CDT	Special Weather Statement	MPX	Polk	38 min
Jul 18, 10:29 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Rusk	31 min
Jul 19, 12:10 AM CDT	Special Weather Statement	MPX	Chippewa	35 min
Jul 19, 12:13 AM CDT	Special Weather Statement	MPX	Eau Claire	47 min
Jul 19, 12:35 AM CDT	Severe Thunderstorm Warning	MPX	Eau Claire	13 min
Jul 19, 1:03 AM CDT	Special Weather Statement	MPX	Eau Claire	27 min
Jul 19, 1:13 AM CDT	Special Weather Statement	MPX	Chippewa	17 min
Jul 19, 1:19 AM CDT	Severe Thunderstorm Warning	MPX	Chippewa	14 min

Nearby

Tornado Warnings in Wisconsin, 2020 Tornado Warnings in Minnesota, 2020 Every tornado warning in 2020 Tornadoes in 2020

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.