Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 15, NWS Twin Cities, MN

May 15, 2021Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at May 15, 2021, 5:07 PM CDT for Saint Croix County, Wisconsin. It was in force for 23 min. 1 report 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: May 15, 2021, 5:07 PM CDT (22:07 UTC)
Expired: May 15, 2021, 5:30 PM CDT
In force: 23 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), 96 km from the middle of the area, began a volume at 22:08 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
May 15, 5:20 PM CDT	HAIL 1.25	5 Ne Roberts, WI

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.1 hours before the alert went out and 98 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: 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.

622 
WUUS53 KMPX 152207
SVRMPX
WIC109-152230-
/O.NEW.KMPX.SV.W.0015.210515T2207Z-210515T2230Z/

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

The National Weather Service in the Twin Cities has issued a

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

* Until 530 PM CDT.

* At 506 PM CDT, a severe thunderstorm was located 8 miles north of
  Baldwin, or 19 miles northeast of River Falls, moving southeast at
  10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Baldwin and Hammond.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4508 9255 4518 9231 4507 9213 4494 9240
TIME...MOT...LOC 2206Z 334DEG 11KT 4509 9237 

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

Dye

1 follow-up statement

231 
WWUS53 KMPX 152218
SVSMPX

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

WIC109-152230-
/O.CON.KMPX.SV.W.0015.000000T0000Z-210515T2230Z/
St. Croix WI-
518 PM CDT Sat May 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM CDT
FOR EAST CENTRAL ST. CROIX COUNTY...

At 518 PM CDT, a severe thunderstorm was located 6 miles northeast of
Baldwin, or 18 miles northeast of River Falls, moving southeast at 15
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.

Locations impacted include...
Baldwin and Hammond. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4505 9252 4511 9239 4504 9219 4494 9240
TIME...MOT...LOC 2218Z 334DEG 11KT 4506 9235 

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

Dye

The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 3:48 PM CDT	Special Weather Statement	MPX	Polk	27 min
May 15, 4:07 PM CDT	Severe Thunderstorm Warning	MPX	Polk	23 min
May 15, 4:29 PM CDT	Severe Thunderstorm Warning	MPX	Polk	22 min
May 15, 4:50 PM CDT	Special Weather Statement	MPX	Saint Croix	40 min
May 15, 5:27 PM CDT	Severe Thunderstorm Warning	MPX	Saint Croix	33 min
May 15, 5:44 PM CDT	Severe Thunderstorm Warning	MPX	Pierce	46 min
May 15, 6:28 PM CDT	Severe Thunderstorm Warning	MPX	Pepin, Pierce	62 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.