Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 15, NWS Twin Cities, MN

May 1, 2001Pierce County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at May 1, 2001, 6:10 PM CDT for Pierce County, Saint Croix County, Wisconsin. It was in force for 50 min. 8 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: May 1, 2001, 6:10 PM CDT (23:10 UTC)
Expired: May 1, 2001, 7:00 PM CDT
In force: 50 min
Issued by: NWS Twin Cities, MN
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 83 km from the middle of the area, began a volume at 23:12 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 1, 6:30 PM CDT	Hail 1.25	River Falls, WI
May 1, 6:30 PM CDT	Hail 1.25	River Falls, WI
May 1, 6:40 PM CDT	Thunderstorm Wind 60 M	River Falls, WI	Measured at Rocky Branch School. Numerous trees down.
May 1, 6:40 PM CDT	Hail 2.75	River Falls, WI	Wind driven baseball size hail damaged houses and vehicles, and knocked out hundreds of windows on the south side of town. The local University was particularly hard hit, including a greenhouse that was destroyed.
May 1, 6:40 PM CDT	Hail 1.75	River Falls, WI	Wind driven hail damaged numerous homes and vehicles on the north side of River Falls.
May 1, 6:40 PM CDT	Thunderstorm Wind 55 E	River Falls, WI	Trees down.
May 1, 6:58 PM CDT	Tornado F0	Ellsworth, WI	Dropped down onto farmland, no damage reported.
May 1, 7:04 PM CDT	Hail 1.75	Baldwin, WI

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

Issued	Product	Office	Lasted
May 1, 3:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.2 hours before the alert went out and 86 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: 771 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS53 KMPX 012310
SVRMSP
WIC093-109-020000-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
610 PM CDT TUE MAY 1 2001

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ST. CROIX COUNTY IN WISCONSIN
  PIERCE COUNTY IN WISCONSIN

* UNTIL 700 PM CDT

* AT 610 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH LARGE
  HAIL 7 MILES NORTHWEST OF RIVER FALLS...MOVING NORTHEAST AT 20 MPH.

* SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...
  RIVER FALLS.
  NEW RICHMOND.
  ELLSWORTH.

THIS IS A DANGEROUS STORM...STAY INDOORS AWAY FROM WINDOWS. SEVERE
THUNDERSTORMS CAN PROD/UCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING.

LAT...LON 4520 9273 4480 9273 4461 9252 4458 9219
          4520 9222

The office that day

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

Issued	Product	Office	Counties	Lasted
May 1, 6:07 PM CDT	Severe Thunderstorm Warning	MPX	Polk	38 min
May 1, 6:47 PM CDT	Tornado Warning	MPX	Pierce	28 min
May 1, 6:54 PM CDT	Severe Thunderstorm Warning	MPX	Barron	51 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.