Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 45, NWS Sioux Falls, SD

May 5, 2002Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 5, 2002, 8:18 PM CDT for Woodbury County, Iowa. It was in force for 42 min. 2 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, 8:18 PM CDT (01:18 UTC)
Expired: May 5, 2002, 9:00 PM CDT
In force: 42 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Woodbury County, IA

The radar

The Omaha radar (KOAX), 97 km from the middle of the area, began a volume at 01:21 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 5, 8:28 PM CDT	Thunderstorm Wind 52 E	Sloan, IA	Thunderstorm winds caused widespread tree damage, and tree limbs falling on power lines caused a power outage that lasted for several hours.
May 5, 8:45 PM CDT	Thunderstorm Wind 61 E	Danbury, IA	Thunderstorm winds caused widespread tree damage. Numerous trees were blown down, including a 3 inch diameter tree snapped off at its base.

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

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.3 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-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 060118
SVRFSD
IAC193-060200-

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN WOODBURY COUNTY IN NORTHWEST IOWA

* UNTIL 900 PM CDT

* AT 818 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 10 MILES SOUTHWEST OF SLOAN...OR ABOUT 3 MILES
  EAST OF MACY...MOVING NORTHEAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SLOAN AROUND 825 PM CDT
  DANBURY AROUND 900 PM CDT

THIS STORM WILL PRODUCE LARGE HAIL AND DAMAGING WIND. GO INSIDE A
STURDY BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4214 9648 4198 9638 4220 9563 4242 9576

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, 7:54 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson	21 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, 8:23 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.