Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 334, NWS Sioux Falls, SD

August 17, 2002Plymouth County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 17, 2002, 12:49 AM CDT for Plymouth County, Iowa. It was in force for 26 min. 1 report 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: Aug 17, 2002, 12:49 AM CDT (05:49 UTC)
Expired: Aug 17, 2002, 1:15 AM CDT
In force: 26 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 104 km from the middle of the area, began a volume at 05:49 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.

What was reported inside it

Time	Report	Where	Remark
Aug 17, 1:22 AM CDT	Hail 1	Le Mars, 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 5.8 hours before the alert went out and 162 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.

703 
WUUS53 KFSD 170549
SVRFSD
IAC149-170615-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1249 AM CDT SAT AUG 17 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

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

* UNTIL 115 AM CDT

* AT 1249 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 4 MILES NORTHWEST OF LE MARS TO
  10 MILES WEST OF HINTON...OR FROM 4 MILES NORTHWEST OF LE MARS TO 9
  MILES NORTHWEST OF SIOUX CITY...MOVING EAST AT 55 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  REMSEN AROUND 100 AM CDT
  KINGSLEY AROUND 110 AM CDT

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

LAT...LON 4289 9620 4258 9649 4257 9588 4289 9588

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, 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, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.