Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 42, NWS Sioux Falls, SD

May 5, 2002Dickinson County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 5, 2002, 7:54 PM CDT for Dickinson County, Iowa. It was in force for 21 min. 3 reports 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 5, 2002, 7:54 PM CDT (00:54 UTC)
Expired: May 5, 2002, 8:15 PM CDT
In force: 21 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Dickinson County, IA

The radar

The Sioux Falls radar (KFSD), 129 km from the middle of the area, began a volume at 00:55 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
May 5, 7:55 PM CDT	Hail 1.75	Okoboji, IA
May 5, 8:05 PM CDT	Hail 1	Superior, IA
May 5, 8:08 PM CDT	Hail 1.75	Superior, 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 watch it was issued in

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

Issued	Product	Office	Lasted
May 5, 4:30 PM CDT	Tornado Watch	SPC	7 hr
May 5, 6:00 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.9 hours before the alert went out and 255 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: 1550 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1621 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KFSD 060054
SVRFSD
IAC059-060115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
754 PM CDT SUN MAY 5 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN DICKINSON COUNTY IN NORTHWEST IOWA

* UNTIL 815 PM CDT

* AT 752 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER OKOBOJI...OR ABOUT 2 MILES NORTH OF
  ARNOLDS PARK...MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SPIRIT LAKE AROUND 800 PM CDT
  SUPERIOR AROUND 810 PM CDT

THIS WARNING EXTENDS THE PREVIOUS WARNING FOR EASTERN PORTIONS OF 
DICKINSON COUNTY. THIS STORM WILL PRODUCE LARGE HAIL AND DAMAGING 
WIND TO 65 MILES AN HOUR. GO INSIDE A STURDY BUILDING AND STAY AWAY 
FROM WINDOWS.

A TORNADO WATCH IS ALSO IN EFFECT FOR THE AREA. SEVERE THUNDERSTORMS
CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. PREPARE TO
MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE SUCH AS A BASEMENT OR
SMALL INTERIOR ROOM IF A TORNADO IS SPOTTED.

LAT...LON 4347 9529 4333 9527 4335 9493 4350 9492

The office that day

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

Issued	Product	Office	Counties	Lasted
May 5, 7:33 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson, Ida, Osceola	27 min
May 5, 7:58 PM CDT	Severe Thunderstorm Warning	FSD	Clay	32 min
May 5, 8:02 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Ida	43 min
May 5, 8:18 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	42 min
May 5, 8:23 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	22 min
May 5, 8:33 PM CDT	Severe Thunderstorm Warning	FSD	Clay	27 min
May 5, 8:43 PM CDT	Severe Thunderstorm Warning	FSD	Ida	47 min
May 5, 8:48 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	27 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2002 Every severe thunderstorm warning in 2002

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.