Alert archive / Iowa / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 12, NWS Sioux Falls, SD

April 10, 20014 counties in Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 10, 2001, 6:00 PM CDT for 4 counties in Iowa. It was in force for 30 min. 1 report 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
Apr 10, 2001, 6:00 PM CDT (23:00 UTC)
Expired
Apr 10, 2001, 6:30 PM CDT
In force
30 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Clay County, IA, Dickinson County, IA, O'Brien County, IA, Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 94 km from the middle of the area, began a volume at 22:59 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

TimeReportWhereRemark
Apr 10, 6:15 PM CDTHail 0.75Boyden, IA

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 nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.0 hours before the alert went out and 220 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, Omaha, NE at 12:00Z on 2001-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Omaha, NE at 12:00Z on 2001-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.1939587897Sfc1 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
2400 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
219 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 KFSD 102303
SVRFSD
IAC041-059-141-167-102330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
600 PM CDT TUE APR 10 2001

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EXTREME NORTHWEST CLAY IN NORTHWEST IOWA
  DICKINSON COUNTY IN NORTHWEST IOWA
  NORTHERN OBRIEN COUNTY IN NORTHWEST IOWA
  NORTHEAST SIOUX COUNTY IN NORTHWEST IOWA

* UNTIL 630 PM CDT

* AT 600 PM CDT...WEATHER SPOTTERS REPORTED TWO SEVERE THUNDERSTORMS.
  ONE WAS 8 MILES SOUTHWEST OF SHELDON...OR 9 MILES NORTHEAST OF ORANGE
  CITY.  THE SECOND WAS 5 MILES NORTHEAST OF HARTLEY...OR 13 MILES WEST
  OF SPENCER. THE STORMS WERE MOVING NORTHEAST AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  SHELDON AROUND 605 PM CDT
  MELVIN...WEST OKOBOJI AROUND 615 PM CDT
  ASHTON...ARNOLDS PARK...OKOBOJI...WAHPETON AROUND 620 PM CDT
  ORLEANS...SPIRIT LAKE AROUND 625 PM CDT
  LAKE PARK AROUND 630 PM CDT

TRAINED WEATHER SPOTTERS REPORTED DIME SIZE HAIL NEAR ORANGE CITY AT
558 PM CDT.

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4303 9618 4317 9535 4349 9498 4344 9571

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 6:19 PM CDTSevere Thunderstorm WarningFSDOsceola26 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2001Every 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.