Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 16, NWS Twin Cities, MN

May 15, 2021Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at May 15, 2021, 5:27 PM CDT for Saint Croix County, Wisconsin. It was in force for 33 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
May 15, 2021, 5:27 PM CDT (22:27 UTC)
Expired
May 15, 2021, 6:00 PM CDT
In force
33 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 94 km from the middle of the area, began a volume at 22:27 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 12:00Z, 10.5 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-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2021-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 12:00Z on 2021-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
894 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

948 
WUUS53 KMPX 152227
SVRMPX
WIC109-152300-
/O.NEW.KMPX.SV.W.0016.210515T2227Z-210515T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
527 PM CDT Sat May 15 2021

The National Weather Service in the Twin Cities has issued a

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

* Until 600 PM CDT.

* At 527 PM CDT, a severe thunderstorm was located over Hammond, or
  12 miles northeast of River Falls, moving southeast at 15 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will be near...
  Woodville around 545 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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


If on or near a lake or river, get away from the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4486 9242 4497 9247 4499 9233 4486 9221
TIME...MOT...LOC 2227Z 336DEG 14KT 4498 9243 

HAIL...1.00IN
WIND...<50MPH
 
$$

ETA
1 follow-up statement
899 
WWUS53 KMPX 152250
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
550 PM CDT Sat May 15 2021

WIC109-152300-
/O.CON.KMPX.SV.W.0016.000000T0000Z-210515T2300Z/
St. Croix WI-
550 PM CDT Sat May 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR SOUTHEASTERN ST. CROIX COUNTY...

At 549 PM CDT, a severe thunderstorm was located near Baldwin, or 11
miles east of River Falls, moving southeast at 15 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

This severe thunderstorm will remain over mainly rural areas of
southeastern St. Croix County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

If on or near a lake or river, get away from the water and move 
indoors or inside a vehicle. remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4486 9237 4490 9236 4491 9226 4489 9224
      4486 9222
TIME...MOT...LOC 2249Z 336DEG 14KT 4490 9238 

HAIL...1.00IN
WIND...<50MPH
 
$$

ETA

The office that day

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

IssuedProductOfficeCountiesLasted
May 15, 3:48 PM CDTSpecial Weather StatementMPXPolk27 min
May 15, 4:07 PM CDTSevere Thunderstorm WarningMPXPolk23 min
May 15, 4:29 PM CDTSevere Thunderstorm WarningMPXPolk22 min
May 15, 4:50 PM CDTSpecial Weather StatementMPXSaint Croix40 min
May 15, 5:07 PM CDTSevere Thunderstorm WarningMPXSaint Croix23 min
May 15, 5:44 PM CDTSevere Thunderstorm WarningMPXPierce46 min
May 15, 6:28 PM CDTSevere Thunderstorm WarningMPXPepin, Pierce62 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 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.