Alert archive / Iowa / Tornado Warnings in 2015

Tornado Warning 33, NWS Sioux Falls, SD

October 23, 2015O'Brien County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Oct 23, 2015, 6:42 PM CDT for O'Brien County, Iowa. It was in force for 14 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: Oct 23, 2015, 6:42 PM CDT (23:42 UTC)
Expired: Oct 23, 2015, 6:56 PM CDT
In force: 14 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), 124 km from the middle of the area, began a volume at 23:45 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 12:00Z, 11.7 hours before the alert went out and 199 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.

708 
WFUS53 KFSD 232342
TORFSD
IAC141-240015-
/O.NEW.KFSD.TO.W.0033.151023T2342Z-151024T0015Z/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

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

* UNTIL 715 PM CDT

* AT 641 PM CDT...A CONFIRMED TORNADO WAS LOCATED OVER SUTHERLAND...
  OR 12 MILES NORTH OF CHEROKEE...MOVING NORTHEAST AT 25 MPH.

  HAZARD...DAMAGING TORNADO. 

  SOURCE...LAW ENFORCEMENT 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. 

* THE TORNADO WILL BE NEAR...
  SUTHERLAND AROUND 650 PM CDT.

AT 639 PM CDT...DAMAGE TO A HOME WAS REPORTED TO A HOME ABOUT 2
MILES NORTH OF LARRABEE.

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
CALUMET.

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 4291 9544 4291 9557 4308 9549 4308 9539
      4296 9539
TIME...MOT...LOC 2341Z 215DEG 21KT 4294 9551 

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

$$

WEISSER

1 follow-up statement

230 
WWUS53 KFSD 232356
SVSFSD

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

IAC141-240005-
/O.CAN.KFSD.TO.W.0033.000000T0000Z-151024T0015Z/
O'BRIEN IA-
656 PM CDT FRI OCT 23 2015

...THE TORNADO WARNING FOR SOUTHEASTERN O'BRIEN COUNTY IS
CANCELLED...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO.
THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 4291 9544 4291 9557 4308 9549 4308 9539
      4296 9539
TIME...MOT...LOC 2354Z 215DEG 21KT 4301 9544 

$$

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, 6:08 PM CDT	Tornado Warning Tornado observed	FSD	O'Brien	37 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, 6:44 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.