Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 96, NWS Cheyenne, WY

July 9, 20214 counties in Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 9, 2021, 9:33 PM MDT for 4 counties in Nebraska. It was in force for 57 min. 8 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: Jul 9, 2021, 9:33 PM MDT (03:33 UTC)
Expired: Jul 9, 2021, 10:30 PM MDT
In force: 57 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.75 in
Wind: 80.0 mph

Counties Box Butte County, NE, Dawes County, NE, Morrill County, NE, Sioux County, NE

The radar

The Cheyenne radar (KCYS), 182 km from the middle of the area, began a volume at 03:34 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
Jul 9, 9:38 PM MDT	HAIL 1	6 W Hemingford, NE
Jul 9, 9:56 PM MDT	TSTM WND GST 60	1 Nw Alliance, NE	FROM CWOP SENSOR NORTHWEST OF ALLIANCE
Jul 9, 10:00 PM MDT	TSTM WND GST 68	Alliance, NE
Jul 9, 10:06 PM MDT	TSTM WND DMG	4 Ssw Alliance, NE	STORM CHASER SOUTH OF ALLIANCE ON HIGHWAY 385 REPORTED WIND DRIVEN GOLF BALL SIZED HAIL. DAMAGED VEHICLES. 2 TO 3 INCH TREE LIMBS ON ROAD. STORM CHASER ALSO REPORTED CONSTRUCTION FENCING WRAPPED AROUND VEHICLES ALONG WITH CONTRUCTION DEBRIS ON ROAD. RESULTED I
Jul 9, 10:06 PM MDT	TSTM WND DMG	4 Ssw Alliance, NE	STORM CHASERS SOUTH OF ALLIANCE ON HIGHWAY 385 REPORTED WIND DRIVEN GOLF BALL SIZED HAIL. ROAD SIGNS TOSSED AROUND NEAR THE SIDE OF THE HIGHWAY. DAMAGED VEHICLES. 2 TO 3 INCH TREE LIMBS ON ROAD.
Jul 9, 10:07 PM MDT	TSTM WND GST 86	5 Se Alliance, NE
Jul 9, 10:07 PM MDT	TSTM WND GST 86	Alliance, NE
Jul 9, 10:07 PM MDT	TSTM WND GST 88	Alliance, 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
Jul 9, 2:16 PM MDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 3.6 hours before the alert went out and 214 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: 2799 J/kg
Mixed-layer CIN: -162 J/kg
Mixed-layer LCL: 1859 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.9

Open this sounding in Storm Lab

The text

As transmitted.

802 
WUUS55 KCYS 100333
SVRCYS
NEC013-045-123-165-100430-
/O.NEW.KCYS.SV.W.0096.210710T0333Z-210710T0430Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
933 PM MDT Fri Jul 9 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Box Butte County in the Panhandle of Nebraska...
  Northern Morrill County in the Panhandle of Nebraska...
  South central Dawes County in the Panhandle of Nebraska...
  Southeastern Sioux County in the Panhandle of Nebraska...

* Until 1030 PM MDT.

THIS INCLUDES THE CITY OF ALLIANCE! 

* At 932 PM MDT, a severe thunderstorm was located 9 miles east of
  Flahertys Corner, or 23 miles northwest of Alliance, moving
  southeast at 65 mph.

  This is a very dangerous storm. Seek shelter immediately inside a 
  sturdy structure! 

  HAZARD...80 mph wind gusts and golf ball size hail.

  SOURCE...Radar indicated.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be heavily damaged. Expect 
           considerable damage to roofs, windows, and vehicles. 
           Extensive tree damage and power outages are likely.

* Locations impacted include...
  Alliance, Hemingford, Wild Horse Butte, Kilpatrick Lake, Alliance
  Airport, Box Butte Campground, Berea, Flahertys Corner, Angora, Box
  Butte Dam and Marsland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

&&

LAT...LON 4165 10292 4200 10337 4200 10339 4222 10369
      4260 10323 4234 10275 4210 10274 4209 10271
      4201 10270 4200 10267 4179 10268 4174 10266
      4174 10264 4164 10265
TIME...MOT...LOC 0332Z 308DEG 55KT 4227 10327 

HAIL...1.75IN
WIND...80MPH
 
$$

Hammer

4 follow-up statements

678 
WWUS55 KCYS 100347
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
947 PM MDT Fri Jul 9 2021

NEC165-100355-
/O.CAN.KCYS.SV.W.0096.000000T0000Z-210710T0430Z/
Sioux NE-
947 PM MDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SIOUX COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
the Panhandle of Nebraska.

LAT...LON 4164 10265 4165 10292 4202 10341 4209 10340
      4209 10345 4225 10344 4229 10336 4249 10330
      4253 10311 4234 10275 4210 10274 4209 10271
      4201 10270 4200 10267 4179 10268 4174 10264
TIME...MOT...LOC 0345Z 308DEG 55KT 4214 10305 

$$

NEC013-045-123-100430-
/O.CON.KCYS.SV.W.0096.000000T0000Z-210710T0430Z/
Box Butte NE-Morrill NE-Dawes NE-
947 PM MDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT
FOR BOX BUTTE...NORTHERN MORRILL AND SOUTH CENTRAL DAWES COUNTIES...

At 945 PM MDT, a severe thunderstorm was located near Berea, or 9 
miles west of Alliance, moving southeast at 65 mph.

THIS INCLUDES THE CITY OF ALLIANCE! Clean up may be underway from 
earlier intense thunderstorms. SEEK SHELTER IMMEDIATELY inside a 
sturdy structure and away from windows!

This is a very dangerous storm.

HAZARD...80 mph wind gusts and golf ball size hail.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

This severe storm will be near...
  Alliance around 955 PM MDT.
  Alliance Airport around 1000 PM MDT.

Other locations impacted by this severe thunderstorm include
Marsland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

&&

LAT...LON 4164 10265 4165 10292 4202 10341 4209 10340
      4209 10345 4225 10344 4229 10336 4249 10330
      4253 10311 4234 10275 4210 10274 4209 10271
      4201 10270 4200 10267 4179 10268 4174 10264
TIME...MOT...LOC 0345Z 308DEG 55KT 4214 10305 

HAIL...1.75IN
WIND...80MPH
 
$$

Hammer

144 
WWUS55 KCYS 100404
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
1004 PM MDT Fri Jul 9 2021

NEC045-100412-
/O.CAN.KCYS.SV.W.0096.000000T0000Z-210710T0430Z/
Dawes NE-
1004 PM MDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL DAWES COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
the Panhandle of Nebraska.

LAT...LON 4164 10265 4165 10292 4204 10329 4216 10330
      4219 10310 4229 10295 4243 10292 4234 10275
      4210 10274 4209 10271 4201 10270 4200 10267
      4179 10268 4174 10264
TIME...MOT...LOC 0402Z 306DEG 50KT 4205 10286 

$$

NEC013-123-100430-
/O.CON.KCYS.SV.W.0096.000000T0000Z-210710T0430Z/
Box Butte NE-Morrill NE-
1004 PM MDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT
FOR SOUTHEASTERN BOX BUTTE AND NORTHEASTERN MORRILL COUNTIES...

At 1002 PM MDT, a severe thunderstorm was located over Alliance
Airport, or near Alliance, moving southeast at 60 mph.

This is a very dangerous storm.

HAZARD...80 mph wind gusts and golf ball size hail.

SOURCE...Trained weather spotters. 70 to 80 MPH winds have been 
         confirmed in and around Alliance with this storm! 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

This severe thunderstorm will continue to impact the city of 
Alliance. Other locations impacted include...Angora.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

&&

LAT...LON 4164 10265 4165 10292 4204 10329 4216 10330
      4219 10310 4229 10295 4243 10292 4234 10275
      4210 10274 4209 10271 4201 10270 4200 10267
      4179 10268 4174 10264
TIME...MOT...LOC 0402Z 306DEG 50KT 4205 10286 

HAIL...1.75IN
WIND...80MPH
 
$$

Hammer

714 
WWUS55 KCYS 100409
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
1009 PM MDT Fri Jul 9 2021

NEC013-123-100430-
/O.CON.KCYS.SV.W.0096.000000T0000Z-210710T0430Z/
Box Butte NE-Morrill NE-
1009 PM MDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT
FOR EASTERN BOX BUTTE AND NORTHEASTERN MORRILL COUNTIES...

At 1008 PM MDT, a severe thunderstorm was located near Alliance
Airport, or 7 miles southeast of Alliance, moving southeast at 60
mph.

This is an extremely dangerous storm capable of substantial damage! 

HAZARD...90 mph wind gusts and golf ball size hail.

SOURCE...Trained weather spotters and automated sensors confirmed. 
         An 86 MPH wind gust was reported in Alliance with this 
         storm! 

IMPACT...You are in a life-threatening situation. Flying debris may 
         be deadly to those caught without shelter. Mobile homes 
         will be heavily damaged or destroyed. Homes and businesses 
         will have substantial roof and window damage. Expect 
         extensive tree damage and power outages.

Locations impacted include...
Alliance, Alliance Airport and Wild Horse Butte. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. This storm has the potential to cause
serious injury and significant property damage.

&&

LAT...LON 4164 10265 4165 10292 4205 10323 4213 10304
      4221 10289 4238 10284 4234 10275 4210 10274
      4209 10271 4201 10270 4200 10267 4179 10268
      4174 10264
TIME...MOT...LOC 0408Z 307DEG 54KT 4201 10279 

HAIL...1.75IN
WIND...90MPH
 
$$

Hammer

219 
WWUS55 KCYS 100425
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
1025 PM MDT Fri Jul 9 2021

NEC013-123-100435-
/O.EXP.KCYS.SV.W.0096.000000T0000Z-210710T0430Z/
Box Butte NE-Morrill NE-
1025 PM MDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN BOX BUTTE AND
NORTHEASTERN MORRILL COUNTIES WILL EXPIRE AT 1030 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
the Panhandle of Nebraska.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Cheyenne.

LAT...LON 4164 10265 4165 10292 4205 10323 4213 10304
      4221 10289 4238 10284 4234 10275 4210 10274
      4209 10271 4201 10270 4200 10267 4179 10268
      4174 10264
TIME...MOT...LOC 0425Z 308DEG 55KT 4186 10254 

$$

Hammer

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 9, 6:07 PM MDT	Tornado Warning	CYS	Morrill	26 min
Jul 9, 8:04 PM MDT	Severe Thunderstorm Warning	CYS	Sioux	41 min
Jul 9, 8:31 PM MDT	Tornado Warning	CYS	Sioux	44 min
Jul 9, 8:47 PM MDT	Severe Thunderstorm Warning	CYS	Dawes	43 min
Jul 9, 9:01 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes, Sioux	44 min
Jul 9, 9:22 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes	38 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.