Alert archive / Nebraska / Tornado Warnings in 2011

Tornado Warning 84, NWS Omaha, NE

August 18, 20114 counties in Nebraska

NWS Omaha, NE issued this tornado warning at Aug 18, 2011, 7:45 PM CDT for 4 counties in Nebraska. It was in force for 30 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: Aug 18, 2011, 7:45 PM CDT (00:45 UTC)
Expired: Aug 18, 2011, 8:15 PM CDT
In force: 30 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon

Counties Boone County, NE, Butler County, NE, Madison County, NE, Platte County, NE

The radar

The Omaha radar (KOAX), 108 km from the middle of the area, began a volume at 00:48 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, 7:52 PM CDT	HAIL 1.5	Newman Grove, NE
Aug 18, 8:10 PM CDT	TSTM WND GST 60	8 Wnw Columbus, NE	WINDS ESTIMATED UP TO 60 MPH

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
Aug 18, 6:38 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.8 hours before the alert went out and 107 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: 1385 J/kg
Mixed-layer CIN: -135 J/kg
Mixed-layer LCL: 582 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 289 m²/s²
0-3 km storm-relative helicity: 636 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 47.4

Open this sounding in Storm Lab

The text

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

070 
WFUS53 KOAX 190045
TOROAX
NEC011-023-119-141-190115-
/O.NEW.KOAX.TO.W.0084.110819T0045Z-110819T0115Z/

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

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN BOONE COUNTY IN NORTHEAST NEBRASKA...
  NORTHWESTERN BUTLER COUNTY IN EAST CENTRAL NEBRASKA...
  SOUTHWESTERN MADISON COUNTY IN NORTHEAST NEBRASKA...
  PLATTE COUNTY IN NORTHEAST NEBRASKA...

* UNTIL 815 PM CDT

* AT 739 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR NEWMAN GROVE...OR 29 MILES SOUTHWEST OF
  NORFOLK...AND MOVING SOUTHEAST AT 35 MPH.

* LOCATIONS IMPACTED INCLUDE...
  NEWMAN GROVE...LINDSAY...ST. EDWARD...PLATTE CENTER...MONROE...    
  DUNCAN.  

THE WARNED AREA INCLUDES HIGHWAY 81 IN NEBRASKA BETWEEN MILE MARKERS
110 AND 137.

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.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR
THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 4192 9795 4182 9757 4161 9726 4138 9725
      4135 9737 4139 9738 4136 9746 4136 9752
      4133 9757 4134 9760 4139 9760 4140 9771
      4152 9771 4152 9788 4151 9789 4167 9804
TIME...MOT...LOC 0043Z 333DEG 43KT 4170 9780

$$

ZAPOTOCNY

2 follow-up statements

621 
WWUS53 KOAX 190058
SVSOAX

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

NEC011-023-119-141-190115-
/O.CON.KOAX.TO.W.0084.000000T0000Z-110819T0115Z/
BOONE NE-BUTLER NE-MADISON NE-PLATTE NE-
758 PM CDT THU AUG 18 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR PLATTE...SOUTHWESTERN
MADISON...BUTLER AND EASTERN BOONE COUNTIES UNTIL 815 PM CDT...

AT 753 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
DANGEROUS STORM WAS LOCATED 5 MILES NORTHEAST OF ST. EDWARD...OR 25 
MILES NORTHWEST OF COLUMBUS...MOVING SOUTHEAST AT 35 MPH.  PING PONG 
BALL SIZE HAIL WAS REPORTED IN NEWMAN GROVE AT 752 PM.  

LOCATIONS IMPACTED INCLUDE...
  ST EDWARD AND RURAL AREAS OF PLATTE COUNTY.  

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.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR
THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 4192 9795 4182 9757 4161 9726 4138 9725
      4135 9737 4139 9738 4136 9746 4136 9752
      4133 9757 4134 9760 4139 9760 4140 9771
      4152 9771 4152 9788 4151 9789 4167 9804
TIME...MOT...LOC 0057Z 333DEG 43KT 4156 9774

$$

ZAPOTOCNY

825 
WWUS53 KOAX 190104
SVSOAX

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

NEC119-190113-
/O.CAN.KOAX.TO.W.0084.000000T0000Z-110819T0115Z/
MADISON NE-
804 PM CDT THU AUG 18 2011

...THE TORNADO WARNING FOR SOUTHWESTERN MADISON COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED SOUTH OF OF THE 
WARNED AREA.

LAT...LON 4174 9791 4174 9754 4161 9726 4138 9725
      4138 9729 4140 9737 4136 9746 4136 9752
      4134 9757 4134 9760 4139 9760 4140 9771
      4152 9771 4152 9788 4151 9789 4160 9798
TIME...MOT...LOC 0103Z 333DEG 43KT 4150 9770

$$

NEC011-141-190115-
/O.CON.KOAX.TO.W.0084.000000T0000Z-110819T0115Z/
BOONE NE-PLATTE NE-
804 PM CDT THU AUG 18 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR PLATTE AND SOUTHEASTERN
BOONE COUNTIES UNTIL 815 PM CDT...

AT 802 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
DANGEROUS STORM WAS LOCATED NEAR GENOA...OR 19 MILES WEST OF
COLUMBUS...MOVING SOUTHEAST AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...
  COLUMBUS...PLATTE CENTER...MONROE AND DUNCAN.

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.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR
THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 4174 9791 4174 9754 4161 9726 4138 9725
      4138 9729 4140 9737 4136 9746 4136 9752
      4134 9757 4134 9760 4139 9760 4140 9771
      4152 9771 4152 9788 4151 9789 4160 9798
TIME...MOT...LOC 0103Z 333DEG 43KT 4150 9770

$$

ZAPOTOCNY

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 7:02 PM CDT	Tornado Warning	OAX	Knox	31 min
Aug 18, 7:15 PM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy, Washington	45 min
Aug 18, 7:21 PM CDT	Tornado Warning	OAX	Antelope, Boone, Madison	39 min
Aug 18, 7:25 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Madison, Stanton	35 min
Aug 18, 7:36 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Sarpy	39 min
Aug 18, 7:47 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Lancaster, Sarpy, Saunders	43 min
Aug 18, 8:11 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Lancaster, Otoe	49 min
Aug 18, 8:18 PM CDT	Severe Thunderstorm Warning	OAX	Boone, Butler, Colfax, Platte	42 min
Aug 18, 8:34 PM CDT	Flash Flood Warning	OAX	Cass, Otoe, Sarpy	6 hr
Aug 18, 8:40 PM CDT	Flash Flood Warning	OAX	Platte	77 min
Aug 18, 8:50 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Seward	40 min
Aug 18, 8:55 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Gage, Johnson, Lancaster, Nemaha, Otoe	38 min
Aug 18, 9:13 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Pawnee, Richardson	47 min
Aug 18, 9:20 PM CDT	Severe Thunderstorm Warning	OAX	Saline, Seward	40 min
Aug 18, 9:35 PM CDT	Areal Flood Advisory	OAX	Cass, Johnson, Lancaster, Nemaha, Otoe	3 hr
Aug 18, 9:49 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson, Lancaster, Otoe, Saline, Seward	41 min
Aug 18, 10:25 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Johnson, Pawnee, Saline	50 min
Aug 18, 11:19 PM CDT	Severe Thunderstorm Warning	OAX	Colfax, Madison, Platte, Stanton	41 min

Nearby

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