Alert archive / Nebraska / Tornado Warnings in 2011

Tornado Warning 78, NWS Omaha, NE

August 18, 2011Antelope County, Nebraska

NWS Omaha, NE issued this tornado warning at Aug 18, 2011, 5:25 PM CDT for Antelope County, Nebraska. It was in force for 50 min. 3 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
Aug 18, 2011, 5:25 PM CDT (22:25 UTC)
Expired
Aug 18, 2011, 6:15 PM CDT
In force
50 min
Issued by
NWS Omaha, NE
Area
Storm-based polygon

County Antelope County, NE

The radar

The Omaha radar (KOAX), 179 km from the middle of the area, began a volume at 22:26 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

TimeReportWhereRemark
Aug 18, 5:46 PM CDTTORNADO3 W Clearwater, NETORNADO ABOUT 3 MILES WEST OF CLEARWATER ON THE GROUND ABOUT ONE MILE. EVENT TIME ESTIMATED 546 PM TO 550 PM.
Aug 18, 5:48 PM CDTTORNADO3 Se Ewing, NELARGE TORNADO SPOTTED NEAR THE COUNTY LINE BECOMING RAIN WRAPPED.
Aug 18, 6:03 PM CDTTORNADOClearwater, NE

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

IssuedProductOfficeLasted
Aug 18, 1:27 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.4 hours before the alert went out and 179 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 12:00Z on 2011-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1181 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2011-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 234 square meters per square second.1939587897Sfc1 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
1181 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
683 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
234 m²/s²
0-3 km storm-relative helicity
385 m²/s²
Significant tornado parameter
0.0
Supercell composite
11.7

Open this sounding in Storm Lab

The text

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

768 
WFUS53 KOAX 182225
TOROAX
NEC003-182315-
/O.NEW.KOAX.TO.W.0078.110818T2225Z-110818T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
525 PM CDT THU AUG 18 2011

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL ANTELOPE COUNTY IN NORTHEAST NEBRASKA...

* UNTIL 615 PM CDT

* AT 521 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD
  NEAR EWING...OR 48 MILES WEST OF NORFOLK. A TORNADO MAY DEVELOP AT
  ANY TIME! DOPPLER RADAR SHOWED THIS TORNADIC STORM MOVING EAST AT
  30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  RURAL AREAS OF WEST CENTRAL ANTELOPE COUNTY.

THE WARNED AREA INCLUDES HIGHWAY 275 IN NEBRASKA BETWEEN MILE MARKERS
25 AND 53.

THE WARNED AREA INCLUDES HIGHWAY 20 IN NEBRASKA BETWEEN MILE MARKERS
329 AND 352.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4240 9830 4239 9784 4203 9783 4212 9831
TIME...MOT...LOC 2224Z 282DEG 26KT 4222 9829

$$

DP/CZ
2 follow-up statements
957 
WWUS53 KOAX 182250
SVSOAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
550 PM CDT THU AUG 18 2011

NEC003-182315-
/O.CON.KOAX.TO.W.0078.000000T0000Z-110818T2315Z/
ANTELOPE NE-
550 PM CDT THU AUG 18 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR CENTRAL ANTELOPE COUNTY
UNTIL 615 PM CDT...

AT 545 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS AND SPOTTERS
WERE TRACKING A CONFIRMED TORNADO.  THIS TORNADO WAS LOCATED 5 MILES
NORTHWEST OF NELIGH...OR 36 MILES WEST OF NORFOLK...MOVING EAST AT 30
MPH.

THIS TORNADO WILL BE NEAR...
  RURAL WEST CENTRAL ANTELOPE COUNTY INCLUDING CLEARWATER AND        
  NELIGH. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4240 9830 4239 9784 4203 9783 4212 9831
TIME...MOT...LOC 2248Z 282DEG 26KT 4218 9806

$$

ZAPOTOCNY
486 
WWUS53 KOAX 182257
SVSOAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
557 PM CDT THU AUG 18 2011

NEC003-182315-
/O.CON.KOAX.TO.W.0078.000000T0000Z-110818T2315Z/
ANTELOPE NE-
557 PM CDT THU AUG 18 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR CENTRAL ANTELOPE COUNTY
UNTIL 615 PM CDT...

AT 554 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO.  THIS
TORNADO WAS LOCATED NEAR CLEARWATER...OR 41 MILES WEST OF NORFOLK...
MOVING SOUTHEAST AT 30 MPH.

THE TORNADO IS APPROACHING...CLEARWATER AND NELIGH.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. TAKE COVER NOW. MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID
WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE
CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4240 9830 4239 9784 4203 9783 4212 9831
TIME...MOT...LOC 2256Z 293DEG 24KT 4218 9817

$$

ZAPOTOCNY

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 12:32 PM CDTSevere Thunderstorm WarningOAXKnox43 min
Aug 18, 12:56 PM CDTSevere Thunderstorm WarningOAXCedar, Knox, Pierce49 min
Aug 18, 1:22 PM CDTSevere Thunderstorm WarningOAXCedar, Knox, Wayne53 min
Aug 18, 3:14 PM CDTSevere Thunderstorm WarningOAXCedar46 min
Aug 18, 3:44 PM CDTSevere Thunderstorm WarningOAXBurt, Dodge, Washington46 min
Aug 18, 3:57 PM CDTSevere Thunderstorm WarningOAXPierce, Wayne63 min
Aug 18, 3:59 PM CDTSevere Thunderstorm WarningOAXCedar20 min
Aug 18, 4:17 PM CDTSevere Thunderstorm WarningOAXBurt, Washington43 min
Aug 18, 4:48 PM CDTSevere Thunderstorm WarningOAXAntelope, Knox57 min
Aug 18, 4:53 PM CDTSevere Thunderstorm WarningOAXThurston52 min
Aug 18, 4:56 PM CDTSevere Thunderstorm WarningOAXDouglas, Washington49 min
Aug 18, 5:20 PM CDTSevere Thunderstorm WarningOAXCass, Douglas, Sarpy40 min
Aug 18, 5:28 PM CDTSevere Thunderstorm WarningOAXCedar47 min
Aug 18, 5:37 PM CDTSevere Thunderstorm WarningOAXAntelope, Knox, Pierce38 min
Aug 18, 5:41 PM CDTFlash Flood WarningOAXDouglas, Washington5 hr
Aug 18, 5:43 PM CDTSevere Thunderstorm WarningOAXBurt, Thurston47 min
Aug 18, 5:50 PM CDTFlash Flood WarningOAXThurston6 hr
Aug 18, 6:01 PM CDTTornado WarningOAXAntelope, Knox44 min
Aug 18, 6:08 PM CDTTornado WarningOAXAntelope52 min
Aug 18, 6:15 PM CDTSevere Thunderstorm WarningOAXBurt, Cuming, Thurston, Wayne45 min
Aug 18, 6:25 PM CDTFlash Flood WarningOAXAntelope3 hr
Aug 18, 6:42 PM CDTSevere Thunderstorm WarningOAXBurt, Washington48 min
Aug 18, 6:56 PM CDTSevere Thunderstorm WarningOAXBurt, Cuming, Dodge, Thurston33 min
Aug 18, 6:57 PM CDTTornado WarningOAXAntelope, Boone, Madison32 min

Nearby

Tornado Warnings in Nebraska, 2011Every tornado warning in 2011Tornadoes in 2011

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.