Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 53, NWS Twin Cities, MN

July 24, 2021Polk County, Saint Croix County, Wisconsin; Chisago County, Washington County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 24, 2021, 2:03 AM CDT for Polk County, Saint Croix County, Wisconsin; Chisago County, Washington County, Minnesota. It was in force for 25 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 24, 2021, 2:03 AM CDT (07:03 UTC)
Expired
Jul 24, 2021, 2:28 AM CDT
In force
25 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Chisago County, MN, Washington County, MN, Polk County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 89 km from the middle of the area, began a volume at 07:03 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

Minneapolis, MN (KMPX), launched 00:00Z, 7.1 hours before the alert went out and 92 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, Minneapolis, MN at 00:00Z on 2021-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2540 joules per kilogram.LCLLFCEL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 2021-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 square meters per square second.19395878Sfc1 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
2540 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1098 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.4

Open this sounding in Storm Lab

The text

As transmitted.

510 
WUUS53 KMPX 240703
SVRMPX
MNC025-163-WIC095-109-240745-
/O.NEW.KMPX.SV.W.0053.210724T0703Z-210724T0745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
203 AM CDT Sat Jul 24 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Southeastern Chisago County in east central Minnesota...
  Northern Washington County in east central Minnesota...
  Northern St. Croix County in west central Wisconsin...
  South central Polk County in northwestern Wisconsin...

* Until 245 AM CDT.

* At 202 AM CDT, a severe thunderstorm was located near Hugo, or 20
  miles northeast of St. Paul, moving east at 40 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Scandia around 210 AM CDT.
  Somerset and Osceola around 215 AM CDT.
  New Richmond around 220 AM CDT.

Other locations in the path of this severe thunderstorm include Star
Prairie, Amery and Clear Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4515 9222 4511 9291 4523 9300 4549 9245
TIME...MOT...LOC 0702Z 255DEG 33KT 4518 9286 

HAIL...1.00IN
WIND...60MPH
 
$$

TDH
2 follow-up statements
545 
WWUS53 KMPX 240718
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
218 AM CDT Sat Jul 24 2021

MNC025-163-WIC095-109-240745-
/O.CON.KMPX.SV.W.0053.000000T0000Z-210724T0745Z/
Chisago MN-Washington MN-St. Croix WI-Polk WI-
218 AM CDT Sat Jul 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 AM CDT
FOR SOUTHEASTERN CHISAGO...NORTHEASTERN WASHINGTON...NORTHERN ST.
CROIX AND SOUTH CENTRAL POLK COUNTIES...

At 217 AM CDT, a severe thunderstorm was located 6 miles north of
Somerset, or 24 miles north of River Falls, moving east at 40 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
  Star Prairie, Amery and Clear Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4515 9222 4513 9267 4525 9295 4549 9245
TIME...MOT...LOC 0717Z 255DEG 33KT 4522 9266 

HAIL...0.75IN
WIND...60MPH
 
$$

TDH
465 
WWUS53 KMPX 240728
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
228 AM CDT Sat Jul 24 2021

MNC025-163-WIC095-109-240737-
/O.CAN.KMPX.SV.W.0053.000000T0000Z-210724T0745Z/
Chisago MN-Washington MN-St. Croix WI-Polk WI-
228 AM CDT Sat Jul 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CHISAGO...
NORTHEASTERN WASHINGTON...NORTHERN ST. CROIX AND SOUTH CENTRAL POLK
COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

LAT...LON 4515 9222 4513 9267 4525 9295 4549 9245
TIME...MOT...LOC 0726Z 255DEG 33KT 4524 9252 

$$

TDH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 2:32 AM CDTSpecial Weather StatementMPXPolk43 min
Jul 24, 12:03 AM CDTSpecial Weather StatementMPXStevens27 min
Jul 24, 12:36 AM CDTSpecial Weather StatementMPXSwift24 min
Jul 24, 1:07 AM CDTSpecial Weather StatementMPXPope23 min
Jul 24, 1:09 AM CDTSpecial Weather StatementMPXDouglas36 min
Jul 24, 1:37 AM CDTSevere Thunderstorm WarningMPXMorrison, Stearns, Todd38 min
Jul 24, 1:46 AM CDTSpecial Weather StatementMPXAnoka44 min
Jul 24, 1:50 AM CDTSpecial Weather StatementMPXDouglas, Todd40 min
Jul 24, 2:16 AM CDTSpecial Weather StatementMPXBenton, Mille Lacs44 min
Jul 24, 2:19 AM CDTSpecial Weather StatementMPXMorrison26 min
Jul 24, 2:27 AM CDTSpecial Weather StatementMPXChisago, Isanti33 min
Jul 24, 3:06 AM CDTSpecial Weather StatementMPXKanabec24 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021Severe Thunderstorm Warnings in Minnesota, 2021Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.