Alert archive / Iowa / Tornado Warnings in 2017

Tornado Warning 21, NWS Sioux Falls, SD

June 29, 2017Woodbury County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Jun 29, 2017, 5:30 PM CDT for Woodbury County, 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: Jun 29, 2017, 5:30 PM CDT (22:30 UTC)
Expired: Jun 29, 2017, 6:00 PM CDT
In force: 30 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Woodbury County, IA

The radar

The Omaha radar (KOAX), 112 km from the middle of the area, began a volume at 22:31 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
Jun 29, 6:00 PM CDT	HAIL 1	1 Nw Smithland, IA

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.

Issued	Product	Office	Lasted
Jun 29, 3:42 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.5 hours before the alert went out and 113 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: 712 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 1324 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

198 
WFUS53 KFSD 292230
TORFSD
IAC193-292300-
/O.NEW.KFSD.TO.W.0021.170629T2230Z-170629T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
530 PM CDT THU JUN 29 2017

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Southeastern Woodbury County in west central Iowa...

* Until 600 PM CDT
    
* At 530 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Hornick, or 25 miles southeast of Sioux City,
  moving east at 20 mph.

  HAZARD...Tornado. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* This dangerous storm will be near...
  Smithland around 550 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Oto.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4230 9607 4237 9570 4221 9569 4221 9612
TIME...MOT...LOC 2230Z 254DEG 17KT 4223 9606 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Weisser

2 follow-up statements

564 
WWUS53 KFSD 292234
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
534 PM CDT THU JUN 29 2017

IAC193-292300-
/O.CON.KFSD.TO.W.0021.000000T0000Z-170629T2300Z/
Woodbury IA-
534 PM CDT THU JUN 29 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 600 PM CDT FOR
SOUTHEASTERN WOODBURY COUNTY...
        
At 534 PM CDT, a confirmed tornado was located near Hornick, or 25
miles southeast of Sioux City, moving east at 20 mph.

HAZARD...Damaging tornado. 

SOURCE...Radar confirmed tornado. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This tornado will be near...
  Smithland around 550 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Oto.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4230 9607 4237 9570 4221 9569 4221 9612
TIME...MOT...LOC 2234Z 254DEG 17KT 4224 9603 

TORNADO...OBSERVED
HAIL...<.75IN

$$

Weisser

437 
WWUS53 KFSD 292248
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
548 PM CDT THU JUN 29 2017

IAC193-292300-
/O.CON.KFSD.TO.W.0021.000000T0000Z-170629T2300Z/
Woodbury IA-
548 PM CDT THU JUN 29 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 600 PM CDT FOR
SOUTHEASTERN WOODBURY COUNTY...
    
At 548 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Smithland, or 25 miles west of Ida Grove, moving
east at 20 mph.

HAZARD...Tornado and golf ball size hail. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This tornadic thunderstorm will remain over mainly rural areas of
southeastern Woodbury County, including the following locations: Oto.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4230 9607 4237 9570 4221 9569 4221 9612
TIME...MOT...LOC 2248Z 259DEG 16KT 4222 9595 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

Weisser

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 3:48 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	42 min
Jun 29, 4:08 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	52 min
Jun 29, 4:23 PM CDT	Tornado Warning	FSD	Woodbury	37 min
Jun 29, 4:26 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	49 min
Jun 29, 4:46 PM CDT	Tornado Warning	FSD	Woodbury	29 min
Jun 29, 4:47 PM CDT	Flash Flood Warning	FSD	Plymouth, Woodbury	3 hr
Jun 29, 4:54 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	51 min
Jun 29, 5:10 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	35 min
Jun 29, 5:29 PM CDT	Severe Thunderstorm Warning	FSD	Clay	33 min
Jun 29, 5:43 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, Sioux	18 min
Jun 29, 5:59 PM CDT	Severe Thunderstorm Warning	FSD	Ida, Woodbury	22 min
Jun 29, 6:27 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Sioux	33 min

Nearby

Tornado Warnings in Iowa, 2017 Every tornado warning in 2017 Tornadoes in 2017

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.