Alert archive / Iowa / Tornado Warnings in 2015

Tornado Warning 30, NWS Sioux Falls, SD

October 23, 2015O'Brien County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Oct 23, 2015, 6:08 PM CDT for O'Brien County, Iowa. It was in force for 37 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: Oct 23, 2015, 6:08 PM CDT (23:08 UTC)
Expired: Oct 23, 2015, 6:45 PM CDT
In force: 37 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Observed
Hail: 0.75 in

County O'Brien County, IA

The radar

The Sioux Falls radar (KFSD), 90 km from the middle of the area, began a volume at 23:07 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.

What was reported inside it

Time	Report	Where	Remark
Oct 23, 6:18 PM CDT	TORNADO	3 E Hospers, IA	ON THE GROUND FOR 3 MINUTES

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 12:00Z, 11.1 hours before the alert went out and 211 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: 28 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 554 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 240 m²/s²
0-3 km storm-relative helicity: 233 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

024 
WFUS53 KFSD 232308
TORFSD
IAC141-232345-
/O.NEW.KFSD.TO.W.0030.151023T2308Z-151023T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
608 PM CDT FRI OCT 23 2015

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN O'BRIEN COUNTY IN NORTHWESTERN IOWA...

* UNTIL 645 PM CDT
    
* AT 608 PM CDT...A TORNADO PRODUCING STORM WAS LOCATED NEAR
  HOSPERS...OR NEAR SHELDON...MOVING NORTHEAST 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 TORNADIC STORM WILL BE NEAR...
  SHELDON AROUND 620 PM CDT.
  SANBORN AROUND 640 PM CDT.

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 4306 9586 4319 9586 4326 9580 4325 9551
TIME...MOT...LOC 2308Z 221DEG 19KT 4311 9586 

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

$$

WEISSER

1 follow-up statement

087 
WWUS53 KFSD 232325
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
625 PM CDT FRI OCT 23 2015

IAC141-232345-
/O.CON.KFSD.TO.W.0030.000000T0000Z-151023T2345Z/
O'BRIEN IA-
625 PM CDT FRI OCT 23 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR
NORTHWESTERN O'BRIEN COUNTY...
        
AT 624 PM CDT...A CONFIRMED TORNADO WAS LOCATED SOUTHEAST OF
SHELDON...MOVING NORTHEAST 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...
  SANBORN AROUND 640 PM CDT.

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 4306 9586 4319 9586 4326 9580 4325 9551
TIME...MOT...LOC 2324Z 220DEG 18KT 4316 9580 

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

$$

WEISSER

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 23, 5:43 PM CDT	Tornado Warning Tornado observed	FSD	Sioux	32 min
Oct 23, 5:45 PM CDT	Tornado Warning	FSD	Cherokee	30 min
Oct 23, 5:47 PM CDT	Tornado Warning	FSD	Plymouth	28 min
Oct 23, 6:12 PM CDT	Tornado Warning	FSD	Plymouth, Sioux	33 min
Oct 23, 6:16 PM CDT	Tornado Warning	FSD	Cherokee, O'Brien	29 min
Oct 23, 6:42 PM CDT	Tornado Warning Tornado observed	FSD	O'Brien	14 min
Oct 23, 6:44 PM CDT	Tornado Warning	FSD	O'Brien, Osceola	31 min

Nearby

Tornado Warnings in Iowa, 2015 Every tornado warning in 2015 Tornadoes in 2015

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.