Alert archive / Iowa / Tornado Warnings in 2013

Tornado Warning 21, NWS Sioux Falls, SD

October 4, 2013Plymouth County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Oct 4, 2013, 7:25 PM CDT for Plymouth County, Iowa. It was in force for 35 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 4, 2013, 7:25 PM CDT (00:25 UTC)
Expired: Oct 4, 2013, 8:00 PM CDT
In force: 35 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Observed
Hail: 1.5 in

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 105 km from the middle of the area, began a volume at 00:29 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.

Issued	Product	Office	Lasted
Oct 4, 2:38 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.4 hours before the alert went out and 156 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: 1572 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 1464 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 224 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.7

Open this sounding in Storm Lab

The text

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

682 
WFUS53 KFSD 050025
TORFSD
IAC149-050100-
/O.NEW.KFSD.TO.W.0021.131005T0025Z-131005T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
725 PM CDT FRI OCT 4 2013

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  PLYMOUTH COUNTY IN NORTHWEST IOWA...

* UNTIL 800 PM CDT

* AT 724 PM CDT...A CONFIRMED LARGE AND EXTREMELY DANGEROUS TORNADO
  WAS LOCATED NEAR HINTON...AND MOVING NORTHEAST AT 40 MPH.

  THIS IS A PARTICULARLY DANGEROUS SITUATION.

  HAZARD...DAMAGING TORNADO.

  SOURCE...WEATHER SPOTTERS CONFIRMED TORNADO.

  IMPACT...YOU ARE IN A LIFE THREATENING SITUATION. MOBILE HOMES WILL
           BE DESTROYED. CONSIDERABLE DAMAGE TO HOMES...BUSINESSES
           AND VEHICLES IS LIKELY AND COMPLETE DESTRUCTION POSSIBLE.
           FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS. EXPECT
           TREES TO BE UPROOTED OR SNAPPED.

* THE TORNADO WILL BE NEAR...
  LE MARS AROUND 740 PM CDT.
  REMSEN AROUND 750 PM CDT.

OTHER LOCATIONS IN THE WARNING INCLUDE OYENS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

&&

LAT...LON 4260 9642 4291 9617 4291 9614 4288 9588
      4256 9621 4256 9625
TIME...MOT...LOC 0026Z 217DEG 37KT 4266 9626

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
HAIL...1.50IN

$$

CHAPMAN

2 follow-up statements

509 
WWUS53 KFSD 050047
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
747 PM CDT FRI OCT 4 2013

IAC149-050100-
/O.CON.KFSD.TO.W.0021.000000T0000Z-131005T0100Z/
PLYMOUTH IA-
747 PM CDT FRI OCT 4 2013

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN PLYMOUTH
COUNTY UNTIL 800 PM CDT...

AT 746 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR LE MARS...AND MOVING NORTHEAST AT 35 MPH.

HAZARD...TORNADO.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE TO
         ROOFS...WINDOWS AND VEHICLES WILL OCCUR. FLYING DEBRIS WILL
         BE DEADLY TO PEOPLE AND ANIMALS. TREE DAMAGE IS LIKELY.

THIS DANGEROUS STORM WILL BE NEAR...
  REMSEN AROUND 755 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING TORNADOES. TAKE COVER IN A
BASEMENT OR STORM SHELTER NOW!

&&

LAT...LON 4268 9610 4270 9618 4284 9622 4291 9617
      4291 9614 4288 9588
TIME...MOT...LOC 0047Z 221DEG 32KT 4278 9608

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

$$

CHAPMAN

527 
WWUS53 KFSD 050058
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
758 PM CDT FRI OCT 4 2013

IAC149-050108-
/O.EXP.KFSD.TO.W.0021.000000T0000Z-131005T0100Z/
PLYMOUTH IA-
758 PM CDT FRI OCT 4 2013

...THE TORNADO WARNING FOR NORTHEASTERN PLYMOUTH COUNTY WILL EXPIRE
AT 800 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND MOVED OUT OF
THE WARNED AREA.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 10 PM CDT.

LAT...LON 4268 9610 4270 9618 4284 9622 4291 9617
      4291 9614 4288 9588
TIME...MOT...LOC 0058Z 219DEG 46KT 4291 9594

$$

CHAPMAN

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 4, 7:22 PM CDT	Tornado Warning Emergency	FSD	Cherokee	38 min
Oct 4, 7:54 PM CDT	Tornado Warning	FSD	Buena Vista, Cherokee	36 min
Oct 4, 8:27 PM CDT	Tornado Warning	FSD	Buena Vista, Clay	33 min
Oct 4, 8:33 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	42 min
Oct 4, 8:55 PM CDT	Tornado Warning	FSD	Clay	20 min

Nearby

Tornado Warnings in Iowa, 2013 Every tornado warning in 2013 Tornadoes in 2013

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.