Alert archive / Iowa / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 147, NWS Sioux Falls, SD

August 11, 20164 counties in Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 11, 2016, 3:15 AM CDT for 4 counties in Iowa. It was in force for 30 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 11, 2016, 3:15 AM CDT (08:15 UTC)
Expired
Aug 11, 2016, 3:45 AM CDT
In force
30 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Lyon County, IA, O'Brien County, IA, Osceola County, IA, Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 83 km from the middle of the area, began a volume at 08:14 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
Aug 11, 3:26 AM CDTTSTM WND DMGHull, IAMULTIPLE TREES DOWNED BLOCKING THE ROADWAY.

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

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 8.3 hours before the alert went out and 200 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 2016-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 812 joules per kilogram.LCLLFCEL10008507005003002001001 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 2016-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 157 square meters per square second.193958Sfc1 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
812 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
1483 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
157 m²/s²
0-3 km storm-relative helicity
311 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.8

Open this sounding in Storm Lab

The text

As transmitted.

932 
WUUS53 KFSD 110815
SVRFSD
IAC119-141-143-167-110845-
/O.NEW.KFSD.SV.W.0147.160811T0815Z-160811T0845Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
315 AM CDT THU AUG 11 2016

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN LYON COUNTY IN NORTHWESTERN IOWA...
  WESTERN O'BRIEN COUNTY IN NORTHWESTERN IOWA...
  NORTHEASTERN SIOUX COUNTY IN NORTHWESTERN IOWA...
  SOUTHWESTERN OSCEOLA COUNTY IN NORTHWESTERN IOWA...

* UNTIL 345 AM CDT

* AT 315 AM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
  EXTENDING FROM ALVORD TO NEAR ROCK VALLEY...MOVING EAST AT 40 MPH.

  HAZARD...60 MPH WIND GUSTS. 

  SOURCE...RADAR INDICATED. 

  IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

* SEVERE THUNDERSTORMS WILL BE NEAR... SIOUX CENTER...HULL AND DOON
  AROUND 325 AM CDT. GEORGE AROUND 335 AM CDT. ORANGE CITY AND
  BOYDEN AROUND 340 AM CDT. SHELDON...ALTON...HOSPERS...GRANVILLE
  AND MATLOCK AROUND 345 AM CDT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 4291 9576 4310 9639 4340 9640 4334 9575
      4291 9573
TIME...MOT...LOC 0815Z 285DEG 35KT 4332 9632 4316 9631 

HAIL...<.75IN
WIND...60MPH
 
$$

BT
2 follow-up statements
170 
WWUS53 KFSD 110829
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
329 AM CDT THU AUG 11 2016

IAC119-141-143-167-110845-
/O.CON.KFSD.SV.W.0147.000000T0000Z-160811T0845Z/
LYON IA-O'BRIEN IA-SIOUX IA-OSCEOLA IA-
329 AM CDT THU AUG 11 2016

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 AM CDT
FOR SOUTHEASTERN LYON...WESTERN O'BRIEN...NORTHEASTERN SIOUX AND
SOUTHWESTERN OSCEOLA COUNTIES...

AT 329 AM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM NEAR GEORGE TO NEAR HULL TO NEAR SIOUX CENTER...MOVING
EAST AT 40 MPH.

HAZARD...60 MPH WIND GUSTS. 

SOURCE...RADAR INDICATED. 

IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

THESE SEVERE STORMS WILL BE NEAR...
  ORANGE CITY AND BOYDEN AROUND 335 AM CDT. 
  ALTON AND MATLOCK AROUND 340 AM CDT. 
  SHELDON...HOSPERS...ASHTON AND GRANVILLE AROUND 345 AM CDT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 4291 9576 4306 9625 4332 9623 4334 9575
      4291 9573
TIME...MOT...LOC 0829Z 290DEG 35KT 4330 9609 4316 9610 4307 9613 

HAIL...<.75IN
WIND...60MPH
 
$$

BT
020 
WWUS53 KFSD 110845
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
345 AM CDT THU AUG 11 2016

IAC119-141-143-167-110855-
/O.EXP.KFSD.SV.W.0147.000000T0000Z-160811T0845Z/
LYON IA-O'BRIEN IA-SIOUX IA-OSCEOLA IA-
345 AM CDT THU AUG 11 2016

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LYON...WESTERN
O'BRIEN...NORTHEASTERN SIOUX AND SOUTHWESTERN OSCEOLA COUNTIES HAS
EXPIRED...
            
THE STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
THEREFORE...THE WARNING HAS BEEN ALLOWED TO EXPIRE.  HOWEVER GUSTY
WINDS ARE STILL POSSIBLE WITH THESE THUNDERSTORMS.

LAT...LON 4291 9576 4306 9625 4332 9623 4334 9575
      4291 9573
TIME...MOT...LOC 0843Z 285DEG 35KT 4330 9609 4316 9610 4307 9613 

$$

BT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 4:01 AM CDTFlash Flood WatchFSDBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more18 hr
Aug 11, 6:17 PM CDTSevere Thunderstorm WarningFSDWoodbury43 min
Aug 11, 6:37 PM CDTSevere Thunderstorm WarningFSDIda, Woodbury53 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2016Every severe thunderstorm warning in 2016

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.