Alert archive / Nebraska / Tornado Warnings in 2012

Tornado Warning 8, NWS Omaha, NE

April 15, 2012Knox County, Nebraska

NWS Omaha, NE issued this tornado warning at Apr 15, 2012, 2:11 PM CDT for Knox County, Nebraska. It was in force for 49 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: Apr 15, 2012, 2:11 PM CDT (19:11 UTC)
Expired: Apr 15, 2012, 3:00 PM CDT
In force: 49 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon

County Knox County, NE

The radar

The Sioux Falls radar (KFSD), 165 km from the middle of the area, began a volume at 19:13 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, 7.2 hours before the alert went out and 197 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: 308 J/kg
Mixed-layer CIN: -118 J/kg
Mixed-layer LCL: 599 m above ground
0-6 km bulk shear: 92 kt
0-1 km storm-relative helicity: 262 m²/s²
0-3 km storm-relative helicity: 342 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

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

524 
WFUS53 KOAX 151911
TOROAX

NEC107-152000-
/O.NEW.KOAX.TO.W.0008.120415T1911Z-120415T2000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
211 PM CDT SUN APR 15 2012

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN KNOX COUNTY IN NORTHEASTERN NEBRASKA...

* UNTIL 300 PM CDT

* AT 210 PM CDT...LOCAL LAW ENFORCEMENT REPORTED A POSSIBLE TORNADO 
  9 MILES NORTHEAST OF ORCHARD...OR 26 MILES EAST OF ONEILL. DOPPLER 
  RADAR SHOWED THIS TORNADO MOVING NORTH AT 10 MPH.

* THIS TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS 
  OF SOUTHWESTERN KNOX COUNTY.

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 IN A MOBILE 
HOME OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND 
PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4261 9814 4256 9802 4243 9803 4243 9811
      4244 9819 4244 9820 4256 9823
TIME...MOT...LOC 1910Z 184DEG 8KT 4244 9812 

$$

DEWALD

1 follow-up statement

229 
WWUS53 KOAX 151923
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
223 PM CDT SUN APR 15 2012

NEC107-152000-
/O.CON.KOAX.TO.W.0008.000000T0000Z-120415T2000Z/
KNOX NE-
223 PM CDT SUN APR 15 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM CDT FOR 
SOUTHWESTERN KNOX COUNTY...

AT 219 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 
CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED 
SOUTHWEST OF VERDIGRE...OR 27 MILES EAST OF ONEILL...MOVING NORTH AT 
15 MPH. 

LOCATIONS IMPACTED INCLUDE...  
MAINLY RURAL AREAS OF SOUTHWESTERN KNOX COUNTY. 

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 IN A MOBILE 
HOME OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND 
PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4261 9814 4256 9802 4245 9804 4243 9811
      4245 9818 4256 9823
TIME...MOT...LOC 1919Z 179DEG 24KT 4252 9812 

$$

DEWALD

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 14, 7:02 PM CDT	Areal Flood Advisory	OAX	Douglas, Sarpy	58 min
Apr 14, 9:17 PM CDT	Wind Advisory	OAX	Antelope, Boone, Burt, Butler, Cass, Cedar and 24 more	31 hr
Apr 14, 9:25 PM CDT	Special Weather Statement	OAX	Platte	35 min
Apr 14, 9:49 PM CDT	Severe Thunderstorm Warning	OAX	Cedar, Pierce, Wayne	26 min
Apr 14, 10:51 PM CDT	Special Weather Statement	OAX	Cedar, Pierce	24 min
Apr 14, 11:01 PM CDT	Severe Thunderstorm Warning	OAX	Saline, Seward	29 min
Apr 14, 11:26 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Seward	34 min
Apr 14, 11:31 PM CDT	Tornado Warning	OAX	Lancaster, Seward	29 min
Apr 14, 11:52 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Lancaster, Sarpy, Saunders	38 min
Apr 15, 12:09 AM CDT	Special Weather Statement	OAX	Nemaha, Richardson	36 min
Apr 15, 12:12 AM CDT	Special Weather Statement	OAX	Douglas	33 min
Apr 15, 12:28 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Douglas, Sarpy	21 min
Apr 15, 12:41 AM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy	34 min
Apr 15, 2:05 AM CDT	Special Weather Statement	OAX	Johnson, Nemaha, Otoe, Pawnee, Richardson	85 min
Apr 15, 10:23 AM CDT	River Flood Warning	OAX	Nemaha	11 hr
Apr 15, 10:23 AM CDT	River Flood Warning	OAX	Richardson	21 hr
Apr 15, 1:53 PM CDT	Special Weather Statement	OAX	Knox	67 min
Apr 15, 2:06 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Knox	54 min
Apr 15, 2:30 PM CDT	Tornado Warning	OAX	Knox	39 min

Nearby

Tornado Warnings in Nebraska, 2012 Every tornado warning in 2012 Tornadoes in 2012

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.