Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 342, NWS Sioux Falls, SD

August 17, 2002Cherokee County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 17, 2002, 1:45 AM CDT for Cherokee County, Iowa. It was in force for 30 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, 1:45 AM CDT (06:45 UTC)
Expired: Aug 17, 2002, 2:15 AM CDT
In force: 30 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Cherokee County, IA

The radar

The Sioux Falls radar (KFSD), 134 km from the middle of the area, began a volume at 06:49 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, 6.8 hours before the alert went out and 159 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.

190 
WUUS53 KFSD 170645
SVRFSD
IAC035-170715-

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHEROKEE COUNTY IN NORTHWEST IOWA

* UNTIL 215 AM CDT

* AT 145 AM CDT...A SEVERE THUNDERSTORM WAS REPORTED 4 MILES WEST OF
  WASHTA...OR ABOUT 23 MILES SOUTHEAST OF LE MARS...MOVING EAST AT 15
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WASHTA AROUND 200 AM CDT
  QUIMBY 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 4271 9586 4257 9586 4258 9542 4269 9541

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, 1:35 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	40 min
Aug 17, 1:39 AM CDT	Severe Thunderstorm Warning	FSD	Ida, Woodbury	36 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.