Alert archive / Nebraska / Tornado Warnings in 2021

Tornado Warning 18, NWS Sioux Falls, SD

December 15, 2021Dakota County, Dixon County, Nebraska

NWS Sioux Falls, SD issued this tornado warning at Dec 15, 2021, 3:59 PM CST for Dakota County, Dixon County, Nebraska. It was in force for 31 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: Dec 15, 2021, 3:59 PM CST (21:59 UTC)
Expired: Dec 15, 2021, 4:30 PM CST
In force: 31 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Dakota County, NE, Dixon County, NE

The radar

The Sioux Falls radar (KFSD), 124 km from the middle of the area, began a volume at 22:01 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
Dec 15, 1:23 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.0 hours before the alert went out and 132 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2165 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 346 m²/s²
0-3 km storm-relative helicity: 384 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

606 
WFUS53 KFSD 152159
TORFSD
NEC043-051-152230-
/O.NEW.KFSD.TO.W.0018.211215T2159Z-211215T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
359 PM CST Wed Dec 15 2021

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Northwestern Dakota County in northeastern Nebraska...
  Southern Dixon County in northeastern Nebraska...

* Until 430 PM CST.

* At 359 PM CST, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located near
  Wakefield, or 20 miles southwest of Ponca, moving northeast at 80
  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.

* These dangerous storms will be near...
  Martinsburg around 410 PM CST.
  Ponca, Jackson In Dakota County and Ponca State Park around 415 PM 
  CST.

Other locations impacted by this tornadic thunderstorm include
Waterbury.

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.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4227 9702 4234 9702 4266 9671 4266 9669
      4265 9669 4261 9671 4255 9663 4252 9663
      4250 9660 4252 9655 4252 9653 4248 9650
      4226 9677 4226 9701
TIME...MOT...LOC 2159Z 218DEG 69KT 4230 9690 

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

$$

SG

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 15, 2:56 AM CST	Dense Fog Advisory	FSD	Dakota, Dixon	6 hr
Dec 15, 3:23 PM CST	Severe Thunderstorm Warning Considerable damage threat	FSD	Dakota, Dixon	67 min
Dec 15, 4:00 PM CST	Tornado Warning	FSD	Dakota	45 min
Dec 15, 4:26 PM CST	Severe Thunderstorm Warning Considerable damage threat	FSD	Dakota, Dixon	34 min

Nearby

Tornado Warnings in Nebraska, 2021 Every tornado warning in 2021 Tornadoes in 2021

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.