Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 340, NWS Sioux Falls, SD

August 17, 2002Buena Vista County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 17, 2002, 1:35 AM CDT for Buena Vista County, Iowa. It was in force for 40 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: Aug 17, 2002, 1:35 AM CDT (06:35 UTC)
Expired: Aug 17, 2002, 2:15 AM CDT
In force: 40 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Buena Vista County, IA

The radar

The Sioux Falls radar (KFSD), 158 km from the middle of the area, began a volume at 06:39 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
Aug 17, 1:05 AM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.6 hours before the alert went out and 192 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: 3070 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 1356 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 229 m²/s²
0-3 km storm-relative helicity: 597 m²/s²
Significant tornado parameter: 3.9
Supercell composite: 18.4

Open this sounding in Storm Lab

The text

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

730 
WUUS53 KFSD 170635
SVRFSD
IAC021-170715-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
135 AM CDT SAT AUG 17 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BUENA VISTA COUNTY IN NORTHWEST IOWA

* UNTIL 215 AM CDT

* AT 135 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 4 MILES NORTHEAST OF LINN GROVE
  TO 8 MILES NORTHWEST OF ALTA...OR FROM 14 MILES SOUTH OF SPENCER TO
  14 MILES NORTHWEST OF STORM LAKE...MOVING SOUTHEAST AT 20 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  SIOUX RAPIDS AROUND 145 AM CDT
  ALTA AROUND 155 AM CDT
  TRUESDALE AROUND 200 AM CDT
  MARATHON AROUND 205 AM CDT
  STORM LAKE AROUND 210 AM CDT
  ALBERT CITY...NEWELL...LAKESIDE AROUND 215 AM CDT

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

LAT...LON 4291 9494 4289 9541 4258 9539 4258 9494

BOUSTEAD

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 16, 9:23 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	52 min
Aug 16, 9:45 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	45 min
Aug 16, 10:15 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	45 min
Aug 16, 11:03 PM CDT	Severe Thunderstorm Warning	FSD	O'Brien	37 min
Aug 16, 11:25 PM CDT	Severe Thunderstorm Warning	FSD	Clay	35 min
Aug 17, 12:49 AM CDT	Severe Thunderstorm Warning	FSD	Plymouth	26 min
Aug 17, 1:06 AM CDT	Severe Thunderstorm Warning	FSD	Woodbury	39 min
Aug 17, 1:08 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee	37 min
Aug 17, 1:13 AM CDT	Severe Thunderstorm Warning	FSD	Plymouth	32 min
Aug 17, 1:15 AM CDT	Severe Thunderstorm Warning	FSD	Clay, O'Brien	45 min
Aug 17, 1:39 AM CDT	Severe Thunderstorm Warning	FSD	Ida, Woodbury	36 min
Aug 17, 1:45 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee	30 min
Aug 17, 2:15 AM CDT	Severe Thunderstorm Warning	FSD	Ida	45 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.