Alert archive / South Dakota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 211, NWS Sioux Falls, SD

September 4, 2012Lyon County, Sioux County, Iowa; 4 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 4, 2012, 8:14 PM CDT for Lyon County, Sioux County, Iowa; 4 counties in South Dakota. It was in force for 46 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
Sep 4, 2012, 8:14 PM CDT (01:14 UTC)
Expired
Sep 4, 2012, 9:00 PM CDT
In force
46 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Lyon County, IA, Sioux County, IA, Clay County, SD, Lincoln County, SD, Turner County, SD, Union County, SD

The radar

The Sioux Falls radar (KFSD), 40 km from the middle of the area, began a volume at 01:15 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

TimeReportWhereRemark
Sep 4, 8:14 PM CDTHAIL 14 Sse Davis, SD

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 4, 7:45 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.2 hours before the alert went out and 215 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-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2012-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2236 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2012-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
2236 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
2432 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.2

Open this sounding in Storm Lab

The text

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

239 
WUUS53 KFSD 050114
SVRFSD
IAC119-167-SDC027-083-125-127-050200-
/O.NEW.KFSD.SV.W.0211.120905T0114Z-120905T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
814 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN LYON COUNTY IN NORTHWEST IOWA...
  WESTERN SIOUX COUNTY IN NORTHWEST IOWA...
  NORTHEASTERN CLAY COUNTY IN SOUTHEAST SOUTH DAKOTA...
  LINCOLN COUNTY IN SOUTHEAST SOUTH DAKOTA...
  SOUTHEASTERN TURNER COUNTY IN SOUTHEAST SOUTH DAKOTA...
  NORTHERN UNION COUNTY IN SOUTHEAST SOUTH DAKOTA...

* UNTIL 900 PM CDT

* AT 815 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
  QUARTER SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE
  STORMS WERE LOCATED ALONG A LINE EXTENDING FROM WORTHING TO 7 MILES
  SOUTH OF CENTERVILLE...AND MOVING NORTHEAST AT 50 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  BERESFORD AROUND 820 PM CDT...
  HARRISBURG...ALCESTER AND CANTON AROUND 825 PM CDT...
  NEWTON HILLS STATE PARK AROUND 830 PM CDT...
  HAWARDEN AND FAIRVIEW AROUND 835 PM CDT...
  LARCHWOOD...INWOOD AND HUDSON AROUND 840 PM CDT...
  LESTER AND ALVORD AROUND 845 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 4350 9627 4293 9635 4291 9702 4341 9692
TIME...MOT...LOC 0115Z 246DEG 43KT 4329 9675 4304 9684
WIND...HAIL 60MPH 1.00IN

$$

CHENARD
2 follow-up statements
299 
WWUS53 KFSD 050142
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
842 PM CDT TUE SEP 4 2012

SDC027-125-050152-
/O.CAN.KFSD.SV.W.0211.000000T0000Z-120905T0200Z/
CLAY SD-TURNER SD-
842 PM CDT TUE SEP 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN TURNER AND
NORTHEASTERN CLAY COUNTIES IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE 
WARNED AREA.

LAT...LON 4301 9681 4345 9661 4350 9627 4294 9635
      4292 9680
TIME...MOT...LOC 0142Z 253DEG 39KT 4332 9638 4295 9653

$$

IAC119-167-SDC083-127-050200-
/O.CON.KFSD.SV.W.0211.000000T0000Z-120905T0200Z/
SIOUX IA-LYON IA-LINCOLN SD-UNION SD-
842 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN
UNION...EASTERN LINCOLN...WESTERN LYON AND WESTERN SIOUX COUNTIES
UNTIL 900 PM CDT...

AT 842 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM INWOOD TO 6 MILES SOUTHWEST OF
HAWARDEN...MOVING EAST AT 45 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  LESTER AROUND 850 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 4301 9681 4345 9661 4350 9627 4294 9635
      4292 9680
TIME...MOT...LOC 0142Z 253DEG 39KT 4332 9638 4295 9653
WIND...HAIL 60MPH 1.00IN

$$

CHENARD
144 
WWUS53 KFSD 050201
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
901 PM CDT TUE SEP 4 2012

IAC119-167-SDC083-127-050210-
/O.EXP.KFSD.SV.W.0211.000000T0000Z-120905T0200Z/
SIOUX IA-LYON IA-LINCOLN SD-UNION SD-
901 PM CDT TUE SEP 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN UNION...EASTERN
LINCOLN...WESTERN LYON AND WESTERN SIOUX COUNTIES HAS EXPIRED...

THE WORST OF THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE 
MOVED OUT OF THE WARNED AREA...HOWEVER SMALL HAIL AND GUSTY WINDS 
ARE STILL POSSIBLE WITH THESE THUNDERSTORMS. ANOTHER WARNING HAS 
BEEN ISSUED TO THE EAST.

LAT...LON 4301 9681 4345 9661 4350 9627 4294 9635
      4292 9680
TIME...MOT...LOC 0142Z 253DEG 39KT 4332 9638 4295 9653

$$

CHENARD

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 8:55 PM CDTSevere Thunderstorm WarningFSDLyon, O'Brien, Osceola, Sioux50 min
Sep 4, 8:57 PM CDTSevere Thunderstorm WarningFSDCherokee, Plymouth, Sioux, Woodbury48 min
Sep 4, 9:32 PM CDTSevere Thunderstorm WarningFSDClay, Dickinson, O'Brien, Osceola58 min
Sep 4, 9:44 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Cherokee, Clay, Ida, O'Brien, Plymouth and 1 more61 min
Sep 4, 10:15 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux45 min
Sep 4, 10:28 PM CDTSevere Thunderstorm WarningFSDClay, Dickinson, O'Brien, Osceola47 min
Sep 4, 10:45 PM CDTSevere Thunderstorm WarningFSDCherokee, O'Brien, Plymouth, Sioux45 min
Sep 4, 11:27 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Cherokee, Ida, Plymouth, Woodbury48 min
Sep 4, 7:13 PM CDTSevere Thunderstorm WarningFSDAurora, Davison, Hanson, Sanborn47 min
Sep 4, 7:37 PM CDTSevere Thunderstorm WarningFSDAurora, Jerauld38 min
Sep 4, 7:49 PM CDTSevere Thunderstorm WarningFSDHanson, Lake, McCook, Miner41 min
Sep 4, 7:59 PM CDTSevere Thunderstorm WarningFSDDavison, Hanson31 min
Sep 4, 8:27 PM CDTSevere Thunderstorm WarningFSDHanson, McCook, Miner33 min
Sep 4, 8:52 PM CDTSevere Thunderstorm WarningFSDLake, Lincoln, McCook, Minnehaha, Moody, Turner38 min
Sep 4, 9:28 PM CDTSevere Thunderstorm WarningFSDMinnehaha, Moody47 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2012Severe Thunderstorm Warnings in Iowa, 2012Every severe thunderstorm warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.