Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 47, NWS Sioux Falls, SD

May 5, 2002Clay County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 5, 2002, 8:33 PM CDT for Clay County, Iowa. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 5, 2002, 8:33 PM CDT (01:33 UTC)
Expired: May 5, 2002, 9:00 PM CDT
In force: 27 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Clay County, IA

The radar

The Sioux Falls radar (KFSD), 162 km from the middle of the area, began a volume at 01:35 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.

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, 1.6 hours before the alert went out and 228 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 060133
SVRFSD
IAC041-060200-

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEAST CLAY COUNTY IN NORTHWEST IOWA

* UNTIL 900 PM CDT

* AT 833 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 4 MILES EAST OF GILLETT GROVE...OR ABOUT 13
  MILES NORTHWEST OF LAURENS...MOVING EAST AT 35 MPH.

HOWEVER THERE IS ALSO ADDITIONAL DEVELOPMENT IN NORTHEAST BUENA 
VISTA COUNTY...WHICH WILL MOVE INTO FAR SOUTHEAST CLAY COUNTY.

THIS CELLS WILL PRODUCE LARGE HAIL UP TO ONE INCH IN SIZE. GO INSIDE 
A STURDY BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4309 9507 4292 9503 4296 9456 4316 9460

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, 8:18 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	42 min
May 5, 8:23 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	22 min
May 5, 8:43 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.