Alert archive / Iowa / Tornado Warnings in 2023

Tornado Warning 3, NWS Sioux Falls, SD

May 12, 2023Plymouth County, Woodbury County, Iowa

NWS Sioux Falls, SD issued this tornado warning at May 12, 2023, 8:16 PM CDT for Plymouth County, Woodbury County, Iowa. It was in force for 29 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
May 12, 2023, 8:16 PM CDT (01:16 UTC)
Expired
May 12, 2023, 8:45 PM CDT
In force
29 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Plymouth County, IA, Woodbury County, IA

The radar

The Sioux Falls radar (KFSD), 125 km from the middle of the area, began a volume at 01:15 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 12, 1:09 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.3 hours before the alert went out and 130 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 2023-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1363 joules per kilogram.LCLEL10008507005003002001001 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 2023-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 square meters per square second.19395878Sfc1 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
1363 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
1536 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
331 m²/s²
Significant tornado parameter
0.6
Supercell composite
8.4

Open this sounding in Storm Lab

The text

As transmitted.

114 
WFUS53 KFSD 130116
TORFSD
IAC149-193-130145-
/O.NEW.KFSD.TO.W.0003.230513T0116Z-230513T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
816 PM CDT Fri May 12 2023

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Northwestern Woodbury County in west central Iowa...
  Southwestern Plymouth County in northwestern Iowa...

* Until 845 PM CDT.
    
* At 816 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Sergeant Bluff, or near Sioux City, moving north
  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 dangerous storm will be near...
  Sioux City around 820 PM CDT.
  Hinton around 840 PM CDT.

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 4244 9639 4247 9638 4249 9640 4249 9642
      4263 9651 4265 9614 4242 9625 4241 9637
TIME...MOT...LOC 0116Z 175DEG 23KT 4246 9631 

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

$$

SST
2 follow-up statements
677 
WWUS53 KFSD 130131 RRA
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
831 PM CDT Fri May 12 2023

IAC149-193-130145-
/O.CON.KFSD.TO.W.0003.000000T0000Z-230513T0145Z/
Woodbury IA-Plymouth IA-
831 PM CDT Fri May 12 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 PM CDT FOR
NORTHWESTERN WOODBURY AND SOUTH CENTRAL PLYMOUTH COUNTIES...
    
At 831 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Hinton, or near Sioux City, moving north 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.

Locations impacted include...
  Hinton.

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 4251 9635 4263 9645 4265 9614 4251 9624
TIME...MOT...LOC 0131Z 175DEG 23KT 4256 9632 

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

$$

SST
798 
WWUS53 KFSD 130141
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
841 PM CDT Fri May 12 2023

IAC149-193-130150-
/O.EXP.KFSD.TO.W.0003.000000T0000Z-230513T0145Z/
Woodbury IA-Plymouth IA-
841 PM CDT Fri May 12 2023

...THE TORNADO WARNING FOR NORTHWESTERN WOODBURY AND SOUTH CENTRAL
PLYMOUTH COUNTIES WILL EXPIRE AT 845 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

A Tornado Watch remains in effect until 900 PM CDT for northwestern
and west central Iowa.

Remember, a Severe Thunderstorm Warning still remains in effect for 
portions of Plymouth and Woodbbury County!

LAT...LON 4251 9635 4263 9645 4265 9614 4251 9624
TIME...MOT...LOC 0140Z 175DEG 23KT 4261 9633 

$$

SST

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 7:27 PM CDTSevere Thunderstorm WarningFSDWoodbury33 min
May 12, 7:46 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury44 min
May 12, 7:50 PM CDTSevere Thunderstorm WarningFSDWoodbury40 min
May 12, 7:55 PM CDTTornado WarningFSDWoodbury35 min
May 12, 8:17 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux28 min
May 12, 8:27 PM CDTSevere Thunderstorm WarningFSDPlymouth, Woodbury48 min
May 13, 11:02 AM CDTRiver Flood WarningFSDDickinson7 days
May 13, 1:48 PM CDTTornado WarningFSDBuena Vista27 min
May 13, 4:25 PM CDTTornado Warning Tornado observedFSDBuena Vista35 min
May 13, 4:36 PM CDTTornado WarningFSDBuena Vista24 min

Nearby

Tornado Warnings in Iowa, 2023Every tornado warning in 2023Tornadoes in 2023

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.