Alert archive / Nebraska / Tornado Warnings in 2011
Tornado Warning 79, NWS Omaha, NE
NWS Omaha, NE issued this tornado warning at Aug 18, 2011, 6:01 PM CDT for Antelope County, Knox County, Nebraska. It was in force for 44 min. 1 report 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, 6:01 PM CDT (23:01 UTC)
- Expired
- Aug 18, 2011, 6:45 PM CDT
- In force
- 44 min
- Issued by
- NWS Omaha, NE
- Area
- Storm-based polygon
Counties Antelope County, NE, Knox County, NE
The radar
The Sioux Falls radar (KFSD), 172 km from the middle of the area, began a volume at 23:03 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 |
|---|---|---|---|
| Aug 18, 6:20 PM CDT | HAIL 1.75 | 9 N Orchard, 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 18, 1:27 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 11.0 hours before the alert went out and 190 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
823 WFUS53 KOAX 182301 TOROAX NEC003-107-182345- /O.NEW.KOAX.TO.W.0079.110818T2301Z-110818T2345Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA 601 PM CDT THU AUG 18 2011 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * TORNADO WARNING FOR... NORTHERN ANTELOPE COUNTY IN NORTHEAST NEBRASKA... SOUTHWESTERN KNOX COUNTY IN NORTHEAST NEBRASKA... * UNTIL 645 PM CDT * AT 559 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A CONFIRMED TORNADO 9 MILES NORTHWEST OF ORCHARD...OR 55 MILES NORTHWEST OF NORFOLK. DOPPLER RADAR SHOWED THIS TORNADO MOVING SOUTHEAST AT 35 MPH. * LOCATIONS IMPACTED INCLUDE... ORCHARD...CREIGHTON...ASHFALL FOSSIL BEDS STATE HISTORICAL PARK... THE HIGHWAY 14 AND 59 JUNCTION...ROYAL AND BRUNSWICK. THE WARNED AREA INCLUDES HIGHWAY 20 IN NEBRASKA BETWEEN MILE MARKERS 329 AND 347. 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 4254 9831 4250 9786 4223 9786 4230 9830 TIME...MOT...LOC 2300Z 306DEG 30KT 4245 9832 $$ ZAPOTOCNY
2 follow-up statements
890 WWUS53 KOAX 182322 SVSOAX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA 622 PM CDT THU AUG 18 2011 NEC003-107-182345- /O.CON.KOAX.TO.W.0079.000000T0000Z-110818T2345Z/ KNOX NE-ANTELOPE NE- 622 PM CDT THU AUG 18 2011 ...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHERN ANTELOPE AND SOUTHWESTERN KNOX COUNTIES UNTIL 645 PM CDT... AT 618 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED NEAR ORCHARD...OR 49 MILES NORTHWEST OF NORFOLK...MOVING SOUTHEAST AT 35 MPH. LOCATIONS IMPACTED INCLUDE... ORCHARD...CREIGHTON...ASHFALL FOSSIL BEDS STATE HISTORICAL PARK...THE HIGHWAY 14 AND 59 JUNCTION...ROYAL AND BRUNSWICK. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS. && LAT...LON 4254 9831 4250 9786 4223 9786 4230 9830 TIME...MOT...LOC 2321Z 306DEG 30KT 4235 9824 $$ ZAPOTOCNY
915 WWUS53 KOAX 182342 SVSOAX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA 642 PM CDT THU AUG 18 2011 NEC003-107-182350- /O.EXP.KOAX.TO.W.0079.000000T0000Z-110818T2345Z/ KNOX NE-ANTELOPE NE- 642 PM CDT THU AUG 18 2011 ...THE TORNADO WARNING FOR NORTHERN ANTELOPE AND SOUTHWESTERN KNOX COUNTIES WILL EXPIRE AT 645 PM CDT... THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE LIMITS. HOWEVER...A TORNADO WARNING IS STILL IN EFFECT FOR PARTS OF ANTELOPE COUNTY UNTIL 7 PM. HEAVY RAIN AND INTENSE LIGHTNING WILL CONTINUE ACROSS PARTS OF NORTH AND CENTRAL ANTELOPE COUNTY THROUGH 730 PM. LAT...LON 4254 9831 4250 9786 4223 9786 4230 9830 TIME...MOT...LOC 2340Z 306DEG 30KT 4226 9807 $$ ZAPOTOCNY
The office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 12:32 PM CDT | Severe Thunderstorm Warning | OAX | Knox | 43 min |
| Aug 18, 12:56 PM CDT | Severe Thunderstorm Warning | OAX | Cedar, Knox, Pierce | 49 min |
| Aug 18, 1:22 PM CDT | Severe Thunderstorm Warning | OAX | Cedar, Knox, Wayne | 53 min |
| Aug 18, 3:14 PM CDT | Severe Thunderstorm Warning | OAX | Cedar | 46 min |
| Aug 18, 3:44 PM CDT | Severe Thunderstorm Warning | OAX | Burt, Dodge, Washington | 46 min |
| Aug 18, 3:57 PM CDT | Severe Thunderstorm Warning | OAX | Pierce, Wayne | 63 min |
| Aug 18, 3:59 PM CDT | Severe Thunderstorm Warning | OAX | Cedar | 20 min |
| Aug 18, 4:17 PM CDT | Severe Thunderstorm Warning | OAX | Burt, Washington | 43 min |
| Aug 18, 4:48 PM CDT | Severe Thunderstorm Warning | OAX | Antelope, Knox | 57 min |
| Aug 18, 4:53 PM CDT | Severe Thunderstorm Warning | OAX | Thurston | 52 min |
| Aug 18, 4:56 PM CDT | Severe Thunderstorm Warning | OAX | Douglas, Washington | 49 min |
| Aug 18, 5:20 PM CDT | Severe Thunderstorm Warning | OAX | Cass, Douglas, Sarpy | 40 min |
| Aug 18, 5:25 PM CDT | Tornado Warning | OAX | Antelope | 50 min |
| Aug 18, 5:28 PM CDT | Severe Thunderstorm Warning | OAX | Cedar | 47 min |
| Aug 18, 5:37 PM CDT | Severe Thunderstorm Warning | OAX | Antelope, Knox, Pierce | 38 min |
| Aug 18, 5:41 PM CDT | Flash Flood Warning | OAX | Douglas, Washington | 5 hr |
| Aug 18, 5:43 PM CDT | Severe Thunderstorm Warning | OAX | Burt, Thurston | 47 min |
| Aug 18, 5:50 PM CDT | Flash Flood Warning | OAX | Thurston | 6 hr |
| Aug 18, 6:08 PM CDT | Tornado Warning | OAX | Antelope | 52 min |
| Aug 18, 6:15 PM CDT | Severe Thunderstorm Warning | OAX | Burt, Cuming, Thurston, Wayne | 45 min |
| Aug 18, 6:25 PM CDT | Flash Flood Warning | OAX | Antelope | 3 hr |
| Aug 18, 6:42 PM CDT | Severe Thunderstorm Warning | OAX | Burt, Washington | 48 min |
| Aug 18, 6:56 PM CDT | Severe Thunderstorm Warning | OAX | Burt, Cuming, Dodge, Thurston | 33 min |
| Aug 18, 6:57 PM CDT | Tornado Warning | OAX | Antelope, Boone, Madison | 32 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.