Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 178, NWS Omaha, NE

August 30, 2021Knox County, Nebraska

NWS Omaha, NE issued this severe thunderstorm warning at Aug 30, 2021, 11:35 PM CDT for Knox County, Nebraska. It was in force for 40 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 30, 2021, 11:35 PM CDT (04:35 UTC)
Expired: Aug 31, 2021, 12:15 AM CDT
In force: 40 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Knox County, NE

The radar

The Sioux Falls radar (KFSD), 157 km from the middle of the area, began a volume at 04:36 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 30, 11:45 PM CDT	HAIL 1.75	Verdigre, NE	TRAINED SPOTTER REPORTED GOLF BALL SIZED HAIL IN VERDIGRE.
Aug 30, 11:50 PM CDT	HAIL 2.5	Verdigre, NE	PUBLIC REPORTED VIA SOCIAL TENNIS BALL SIZE HAIL.

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 30, 9:57 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.6 hours before the alert went out and 199 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: 1443 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 1305 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 143 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.5

Open this sounding in Storm Lab

The text

As transmitted.

698 
WUUS53 KOAX 310435
SVROAX
NEC107-310515-
/O.NEW.KOAX.SV.W.0178.210831T0435Z-210831T0515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Omaha/Valley Nebraska
1135 PM CDT Mon Aug 30 2021

The National Weather Service in Omaha has issued a

* Severe Thunderstorm Warning for...
  Southwestern Knox County in northeastern Nebraska...

* Until 1215 AM CDT.

* At 1134 PM CDT, a severe thunderstorm was located near Verdigre, or
  28 miles east of O'Neill, moving southeast at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Verdigre around 1145 PM CDT.

Other locations in the path of this severe thunderstorm include
Creighton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4271 9815 4259 9777 4244 9788 4244 9821
      4257 9831
TIME...MOT...LOC 0434Z 300DEG 18KT 4260 9812 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DeWald

1 follow-up statement

598 
WWUS53 KOAX 310449
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
1149 PM CDT Mon Aug 30 2021

NEC107-310515-
/O.CON.KOAX.SV.W.0178.000000T0000Z-210831T0515Z/
Knox NE-
1149 PM CDT Mon Aug 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT
FOR SOUTHWESTERN KNOX COUNTY...

At 1148 PM CDT, a severe thunderstorm was located over Verdigre, or
30 miles south of Tyndall, moving southeast at 20 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
  Creighton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4259 9777 4244 9788 4244 9821 4253 9828
      4269 9808
TIME...MOT...LOC 0448Z 300DEG 18KT 4256 9803 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DeWald

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 30, 10:29 PM CDT	Severe Thunderstorm Warning	OAX	Cedar, Knox, Pierce, Wayne	46 min
Aug 30, 10:31 PM CDT	Severe Thunderstorm Warning	OAX	Wayne	44 min
Aug 30, 10:54 PM CDT	Severe Thunderstorm Warning	OAX	Cedar	39 min
Aug 30, 11:01 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cuming, Stanton, Wayne	44 min
Aug 30, 11:06 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Pierce, Wayne	54 min
Aug 30, 11:22 PM CDT	Special Weather Statement	OAX	Pierce	23 min
Aug 30, 11:42 PM CDT	Severe Thunderstorm Warning	OAX	Cuming, Stanton, Wayne	48 min
Aug 30, 11:54 PM CDT	Severe Thunderstorm Warning	OAX	Madison, Pierce, Stanton, Wayne	24 min
Aug 31, 12:00 AM CDT	Severe Thunderstorm Warning	OAX	Colfax, Cuming, Dodge, Stanton	45 min
Aug 31, 12:04 AM CDT	Areal Flood Advisory	OAX	Cedar, Cuming, Knox, Pierce, Stanton, Thurston and 1 more	6 hr
Aug 31, 12:09 AM CDT	Severe Thunderstorm Warning	OAX	Antelope, Knox, Pierce	36 min
Aug 31, 12:15 AM CDT	Severe Thunderstorm Warning	OAX	Washington	26 min
Aug 31, 12:25 AM CDT	Areal Flood Advisory	OAX	Burt, Washington	5 hr
Aug 31, 12:31 AM CDT	Severe Thunderstorm Warning	OAX	Burt, Cuming, Dodge, Saunders, Washington	29 min
Aug 31, 12:47 AM CDT	Areal Flood Advisory	OAX	Knox	5 hr
Aug 31, 12:53 AM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Douglas, Saunders, Washington	37 min
Aug 31, 1:19 AM CDT	Areal Flood Advisory	OAX	Burt, Washington	4 hr
Aug 31, 1:22 AM CDT	Areal Flood Advisory	OAX	Burt, Colfax, Cuming, Dodge, Stanton, Thurston and 1 more	6 hr
Aug 31, 1:22 AM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Saunders, Washington	23 min
Aug 31, 1:35 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Douglas, Sarpy, Saunders	25 min
Aug 31, 1:36 AM CDT	Flash Flood Warning	OAX	Antelope, Knox, Pierce	4 hr
Aug 31, 1:46 AM CDT	Areal Flood Advisory	OAX	Dodge, Douglas, Sarpy, Washington	5 hr
Aug 31, 1:56 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Lancaster, Sarpy, Saunders	34 min
Aug 31, 2:14 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	31 min
Aug 31, 3:18 AM CDT	Special Weather Statement	OAX	Antelope	27 min
Aug 31, 5:02 AM CDT	Special Weather Statement	OAX	Butler	28 min
Aug 31, 5:26 AM CDT	Special Weather Statement	OAX	Butler	34 min
Aug 31, 5:35 AM CDT	Areal Flood Advisory	OAX	Butler, Cass, Colfax, Dodge, Douglas, Lancaster and 4 more	77 min
Aug 31, 5:41 AM CDT	Areal Flood Warning	OAX	Antelope, Burt, Cedar, Colfax, Cuming, Dodge and 7 more	9 hr
Aug 31, 5:56 AM CDT	Special Weather Statement	OAX	Seward	34 min
Aug 31, 6:18 AM CDT	Special Weather Statement	OAX	Cass, Lancaster, Otoe, Saline	27 min
Aug 31, 6:28 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Gage, Johnson, Lancaster, Nemaha, Otoe and 1 more	47 min
Aug 31, 6:43 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Johnson, Lancaster, Pawnee, Saline	32 min
Aug 31, 7:12 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Johnson, Nemaha, Otoe, Pawnee and 1 more	48 min
Aug 31, 7:58 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Johnson, Nemaha, Pawnee, Richardson	10 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2021 Every severe thunderstorm warning in 2021

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.