Alert archive / Nebraska / Tornado Warnings in 2012

Tornado Warning 9, NWS Omaha, NE

April 15, 2012Knox County, Nebraska

NWS Omaha, NE issued this tornado warning at Apr 15, 2012, 2:30 PM CDT for Knox County, Nebraska. It was in force for 39 min. 2 reports 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: Apr 15, 2012, 2:30 PM CDT (19:30 UTC)
Expired: Apr 15, 2012, 3:09 PM CDT
In force: 39 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon

County Knox County, NE

The radar

The Sioux Falls radar (KFSD), 147 km from the middle of the area, began a volume at 19:31 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

Time	Report	Where	Remark
Apr 15, 2:35 PM CDT	TORNADO	1 N Santee, NE	ROPE TORNADO. BRIEF TOUCHDOWN.
Apr 15, 2:38 PM CDT	FUNNEL CLOUD	3 Se Niobrara, NE

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, 7.5 hours before the alert went out and 208 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.

243 
WFUS53 KOAX 151930
TOROAX

NEC107-152030-
/O.NEW.KOAX.TO.W.0009.120415T1930Z-120415T2030Z/

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

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

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

* UNTIL 330 PM CDT

* AT 227 PM CDT...DOPPLER RADAR INDICATED A LINE OF SEVERE 
  THUNDERSTORMS CAPABLE OF PRODUCING TORNADOS. THESE STORMS WERE 
  LOCATED NEAR VERDIGRE...OR 31 MILES EAST OF ONEILL...AND MOVING 
  NORTH AT 25 MPH. SPOTTERS REPORTED A VERY BRIEF TORNADO TOUCHDOWN 
  1 MILE SOUTH OF VERDIGRE AT 227 PM. 

* LOCATIONS IMPACTED INCLUDE...
  VERDIGRE...NIOBRARA...SANTEE AND VERDEL. 

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 4283 9815 4276 9801 4277 9794 4280 9790
      4287 9786 4285 9776 4256 9795 4244 9809
      4244 9823 4244 9824 4259 9829 4288 9831
TIME...MOT...LOC 1927Z 176DEG 22KT 4261 9807 

$$

DEWALD

4 follow-up statements

666 
WWUS53 KOAX 151939
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
239 PM CDT SUN APR 15 2012

NEC107-152030-
/O.CON.KOAX.TO.W.0009.000000T0000Z-120415T2030Z/
KNOX NE-
239 PM CDT SUN APR 15 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR KNOX 
COUNTY...

AT 236 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD 
JUST EAST OF NIOBRARA. A TORNADO MAY DEVELOP AT ANY TIME. THIS 
DANGEROUS STORM WAS LOCATED NEAR NIOBRARA...OR 31 MILES WEST OF 
YANKTON...MOVING NORTHWEST AT 15 MPH. THUNDERSTORMS ALSO EXTEND 
SOUTHWARD TOWARD VERDIGRE AS WELL THAT COULD ALSO PRODUCE FUNNEL 
CLOUDS OR TORNADOES. 

LOCATIONS IMPACTED INCLUDE...
VERDIGRE...NIOBRARA...SANTEE AND VERDEL. 

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 4283 9815 4276 9801 4277 9794 4280 9790
      4287 9786 4285 9776 4256 9795 4244 9809
      4244 9823 4244 9824 4259 9829 4288 9831
TIME...MOT...LOC 1936Z 150DEG 11KT 4273 9797 

$$

DEWALD

332 
WWUS53 KOAX 151948
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
248 PM CDT SUN APR 15 2012

NEC107-152030-
/O.CON.KOAX.TO.W.0009.000000T0000Z-120415T2030Z/
KNOX NE-
248 PM CDT SUN APR 15 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR KNOX 
COUNTY...

AT 245 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 
CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED 
NEAR NIOBRARA...OR 31 MILES WEST OF YANKTON...MOVING NORTHWEST AT 
15 MPH. ADDITIONAL FUNNEL CLOUDS COULD STILL DEVELOP SOUTHWEST ALONG 
A LINE OF SHOWERS THAT EXTENDS INTO SOUTHWESTERN KNOX COUNTY. 

LOCATIONS IMPACTED INCLUDE...
VERDIGRE...NIOBRARA...SANTEE AND VERDEL. 

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 4283 9815 4277 9805 4276 9801 4277 9794
      4280 9790 4287 9786 4285 9781 4259 9800
      4248 9811 4247 9823 4259 9829 4288 9831
TIME...MOT...LOC 1945Z 150DEG 11KT 4275 9799 

$$

DEWALD

400 
WWUS53 KOAX 152000
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
300 PM CDT SUN APR 15 2012

NEC107-152030-
/O.CON.KOAX.TO.W.0009.000000T0000Z-120415T2030Z/
KNOX NE-
300 PM CDT SUN APR 15 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR WEST 
CENTRAL KNOX COUNTY...

AT 254 PM CDT...DOPPLER RADAR CONTINUED TO INDICATE AN AREA OF 
SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF WESTERN KNOX COUNTY. 
THIS AREA HAS REMAINED NEARLY STATIONARY. BRIEF TORNADO TOUCHDOWNS 
HAVE OCCURRED NEAR VERDIGRE AND SANTEE...AND A FUNNEL CLOUD WAS 
OBSERVED NEAR NIOBRARA. THIS CLUSTER OF SHOWERS MAY STILL PRODUCE AN 
ISOLATED FUNNEL CLOUD WHICH COULD BRIEFLY TOUCH DOWN. 

LOCATIONS IMPACTED INCLUDE...
VERDIGRE...NIOBRARA AND SANTEE. 

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 4285 9781 4259 9800 4248 9811 4247 9823
      4259 9828 4272 9820 4280 9811 4276 9803
      4277 9794 4280 9790 4287 9786
TIME...MOT...LOC 1954Z 176DEG 22KT 4280 9799 

$$

DEWALD

624 
WWUS53 KOAX 152009
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
309 PM CDT SUN APR 15 2012

NEC107-152040-
/O.CAN.KOAX.TO.W.0009.000000T0000Z-120415T2030Z/
KNOX NE-
309 PM CDT SUN APR 15 2012

...THE TORNADO WARNING FOR WEST CENTRAL KNOX COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND NO LONGER 
APPEARS CAPABLE OF PRODUCING A TORNADO. THEREFORE THE WARNING HAS 
BEEN CANCELLED. 

LAT...LON 4285 9781 4259 9800 4248 9811 4247 9823
      4259 9828 4272 9820 4280 9811 4276 9803
      4277 9794 4280 9790 4287 9786
TIME...MOT...LOC 2008Z 176DEG 22KT 4280 9799 

$$

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, 2:11 PM CDT	Tornado Warning	OAX	Knox	49 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.