Alert archive / South Dakota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 75, NWS Sioux Falls, SD

May 21, 2011Clay County, Turner County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 21, 2011, 7:05 PM CDT for Clay County, Turner County, South Dakota. It was in force for 25 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 21, 2011, 7:05 PM CDT (00:05 UTC)
Expired: May 21, 2011, 7:30 PM CDT
In force: 25 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 58.0 mph

Counties Clay County, SD, Turner County, SD

The radar

The Sioux Falls radar (KFSD), 83 km from the middle of the area, began a volume at 00:07 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.1 hours before the alert went out and 180 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: 1436 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1205 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 145 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

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

809 
WUUS53 KFSD 220005
SVRFSD
SDC027-125-220030-
/O.NEW.KFSD.SV.W.0075.110522T0005Z-110522T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
705 PM CDT SAT MAY 21 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLAY COUNTY IN SOUTHEAST SOUTH DAKOTA...
  SOUTHEASTERN TURNER COUNTY IN SOUTHEAST SOUTH DAKOTA...

* UNTIL 730 PM CDT

* AT 705 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
  HAIL.  THIS STORM WAS LOCATED NEAR MECKLING...OR 7 MILES WEST OF
  VERMILLION...AND MOVING NORTH AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MECKLING AROUND 710 PM CDT...
  WAKONDA AROUND 730 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4273 9696 4276 9698 4276 9703 4277 9708
      4276 9712 4278 9715 4315 9709 4312 9692
      4308 9692 4308 9681 4273 9692
TIME...MOT...LOC 0005Z 195DEG 27KT 4280 9705
WIND...HAIL <58MPH 1.00IN

$$

HANKO

1 follow-up statement

023 
WWUS53 KFSD 220021
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
721 PM CDT SAT MAY 21 2011

SDC027-125-220030-
/O.CON.KFSD.SV.W.0075.000000T0000Z-110522T0030Z/
CLAY SD-TURNER SD-
721 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
TURNER AND CLAY COUNTIES UNTIL 730 PM CDT...

AT 721 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
STORM WAS LOCATED 6 MILES NORTHEAST OF MECKLING...OR 10 MILES
NORTHWEST OF VERMILLION...MOVING NORTH AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  WAKONDA AROUND 730 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4273 9696 4276 9698 4276 9703 4277 9708
      4276 9712 4278 9715 4315 9709 4312 9692
      4308 9692 4308 9681 4273 9692
TIME...MOT...LOC 0021Z 195DEG 27KT 4292 9701
WIND...HAIL <58MPH 1.00IN

$$

HANKO

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 7:28 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Lincoln, Turner	32 min
May 21, 7:38 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	37 min
May 21, 7:49 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Union	26 min
May 21, 8:16 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	29 min
May 21, 8:39 PM CDT	Severe Thunderstorm Warning	FSD	Minnehaha, Moody	36 min
May 22, 10:52 AM CDT	River Flood Warning	FSD	Minnehaha, Moody	22 hr

Nearby

Severe Thunderstorm Warnings in South Dakota, 2011 Every severe thunderstorm warning in 2011

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.