Alert archive / Iowa / Tornado Warnings in 2015

Tornado Warning 31, NWS Sioux Falls, SD

October 23, 2015Plymouth County, Sioux County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Oct 23, 2015, 6:12 PM CDT for Plymouth County, Sioux County, Iowa. It was in force for 33 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, 6:12 PM CDT (23:12 UTC)
Expired
Oct 23, 2015, 6:45 PM CDT
In force
33 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Plymouth County, IA, Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 98 km from the middle of the area, began a volume at 23:12 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
Oct 23, 6:36 PM CDTFUNNEL CLOUD6 S Alton, IA

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, 11.2 hours before the alert went out and 174 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 12:00Z on 2015-10-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 28 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 12:00Z on 2015-10-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 240 square meters per square second.1939587897Sfc1 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
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.

080 
WFUS53 KFSD 232312
TORFSD
IAC149-167-232345-
/O.NEW.KFSD.TO.W.0031.151023T2312Z-151023T2345Z/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN SIOUX COUNTY IN NORTHWESTERN IOWA...
  NORTHEASTERN PLYMOUTH COUNTY IN NORTHWESTERN IOWA...

* UNTIL 645 PM CDT
    
* AT 611 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED NEAR LE MARS...MOVING NORTHEAST AT 25 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 TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
  SOUTHEASTERN SIOUX AND NORTHEASTERN PLYMOUTH COUNTIES...INCLUDING
  THE FOLLOWING LOCATIONS...OYENS.

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 4280 9615 4290 9617 4298 9586 4285 9586
TIME...MOT...LOC 2311Z 241DEG 21KT 4285 9612 

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

$$

WEISSER
2 follow-up statements
702 
WWUS53 KFSD 232329 RRA
SVSFSD

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

IAC149-167-232345-
/O.CON.KFSD.TO.W.0031.000000T0000Z-151023T2345Z/
SIOUX IA-PLYMOUTH IA-
629 PM CDT FRI OCT 23 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR
SOUTHEASTERN SIOUX AND NORTHEASTERN PLYMOUTH COUNTIES...
    
AT 629 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR ALTON...OR 7 MILES SOUTHEAST OF ORANGE CITY...MOVING
NORTHEAST AT 25 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 TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
SOUTHEASTERN SIOUX AND NORTHEASTERN PLYMOUTH COUNTIES.

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 4283 9601 4292 9607 4298 9586 4285 9586
TIME...MOT...LOC 2329Z 241DEG 21KT 4290 9599 

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

$$

WEISSER
126 
WWUS53 KFSD 232345
SVSFSD

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

IAC149-167-232355-
/O.EXP.KFSD.TO.W.0031.000000T0000Z-151023T2345Z/
SIOUX IA-PLYMOUTH IA-
645 PM CDT FRI OCT 23 2015

...THE TORNADO WARNING FOR SOUTHEASTERN SIOUX AND NORTHEASTERN
PLYMOUTH COUNTIES HAS EXPIRED...
        
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE LIMITS
AND EXITED THE WARNED AREA. THEREFORE THE WARNING HAS BEEN ALLOWED TO
EXPIRE.

LAT...LON 4283 9601 4292 9607 4298 9586 4285 9586
TIME...MOT...LOC 2343Z 241DEG 21KT 4290 9599 

$$

WEISSER

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 23, 5:43 PM CDTTornado Warning Tornado observedFSDSioux32 min
Oct 23, 5:45 PM CDTTornado WarningFSDCherokee30 min
Oct 23, 5:47 PM CDTTornado WarningFSDPlymouth28 min
Oct 23, 6:08 PM CDTTornado Warning Tornado observedFSDO'Brien37 min
Oct 23, 6:16 PM CDTTornado WarningFSDCherokee, O'Brien29 min
Oct 23, 6:42 PM CDTTornado Warning Tornado observedFSDO'Brien14 min
Oct 23, 6:44 PM CDTTornado WarningFSDO'Brien, Osceola31 min

Nearby

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