Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 90, NWS Cheyenne, WY

July 9, 2021Box Butte County, Morrill County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 9, 2021, 5:58 PM MDT for Box Butte County, Morrill County, Nebraska. It was in force for 47 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: Jul 9, 2021, 5:58 PM MDT (23:58 UTC)
Expired: Jul 9, 2021, 6:45 PM MDT
In force: 47 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Possible
Hail: 2.75 in
Wind: 60.0 mph

Counties Box Butte County, NE, Morrill County, NE

The radar

The Cheyenne radar (KCYS), 187 km from the middle of the area, began a volume at 00:02 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, 6:12 PM MDT	HAIL 3	11 Wsw Alliance, NE	LATE REPORT. HAIL DIAMETER OF 3.5 INCHES SOUTHWEST OF ALLIANCE.
Jul 9, 6:19 PM MDT	HAIL 3.3	9 Ne Angora, NE
Jul 9, 6:20 PM MDT	HAIL 2.5	12 Ssw 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 12:00Z, 12.0 hours before the alert went out and 216 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: 93 J/kg
Mixed-layer CIN: -824 J/kg
Mixed-layer LCL: 1724 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

766 
WUUS55 KCYS 092358
SVRCYS
NEC013-123-100045-
/O.NEW.KCYS.SV.W.0090.210709T2358Z-210710T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
558 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...
  Northeastern Morrill County in the Panhandle of Nebraska...

* Until 645 PM MDT.

* At 556 PM MDT, a severe thunderstorm was located over Alliance 
  Airport, or near Alliance, moving southeast at 25 mph. Additional 
  storms were located west of Alliance moving southeast, including a 
  Tornado Warned storm until 615 PM MDT.

  This is a very dangerous storm.

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

  SOURCE...Trained weather spotters.

  IMPACT...People and animals outdoors will be severely injured. 
           Expect shattered windows, extensive damage to roofs, 
           siding, and vehicles.

* Locations impacted include...
  Alliance, Hemingford, Kilpatrick Lake, Berea and Alliance Airport. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows!

&&

LAT...LON 4171 10288 4215 10336 4234 10335 4236 10313
      4214 10274 4210 10274 4209 10271 4201 10270
      4200 10267 4182 10268
TIME...MOT...LOC 2356Z 305DEG 23KT 4203 10278 

TORNADO...POSSIBLE
HAIL...2.75IN
WIND...60MPH
 
$$

Brothers

3 follow-up statements

289 
WWUS55 KCYS 100019
SVSCYS

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

NEC013-123-100045-
/O.CON.KCYS.SV.W.0090.000000T0000Z-210710T0045Z/
Box Butte NE-Morrill NE-
619 PM MDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR SOUTHEASTERN BOX BUTTE AND NORTHEASTERN MORRILL COUNTIES...

At 617 PM MDT, a severe thunderstorm was located 9 miles southwest of
Alliance Airport, or 9 miles southwest of Alliance, moving southeast 
at 30 mph. This includes the Tornado Warned storm moving into 
Morrill County. Trained spotters have reported hail greater than 
four inch diameter with these storms.

This is a very dangerous storm.

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

SOURCE...Trained weather spotters.

IMPACT...People and animals outdoors will be severely injured. 
         Expect shattered windows, extensive damage to roofs, 
         siding, and vehicles.

Locations impacted include...
Alliance and Alliance Airport. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 4201 10321 4222 10288 4214 10274 4210 10274
      4209 10271 4201 10270 4200 10267 4182 10268
      4171 10288
TIME...MOT...LOC 0017Z 313DEG 37KT 4197 10296 

TORNADO...POSSIBLE
HAIL...4.00IN
WIND...60MPH
 
$$

Brothers

755 
WWUS55 KCYS 100029
SVSCYS

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

NEC013-100037-
/O.CAN.KCYS.SV.W.0090.000000T0000Z-210710T0045Z/
Box Butte NE-
629 PM MDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BOX BUTTE 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 900 PM MDT for
the Panhandle of Nebraska.

LAT...LON 4171 10288 4184 10302 4200 10311 4200 10279
      4201 10278 4201 10269 4200 10267 4182 10268
TIME...MOT...LOC 0027Z 305DEG 23KT 4193 10289 

$$

NEC123-100045-
/O.CON.KCYS.SV.W.0090.000000T0000Z-210710T0045Z/
Morrill NE-
629 PM MDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR NORTHEASTERN MORRILL COUNTY...

At 627 PM MDT, a severe thunderstorm was located 9 miles southwest of
Alliance Airport, or 11 miles south of Alliance, moving southeast at 
25 mph. This includes the Tornado Warned Storm in Morril County. 
Tennis ball size hail was reported south of Alliance along US-385 
at 625 PM MDT. 

This is a very dangerous storm.

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

SOURCE...Trained weather spotters.

IMPACT...People and animals outdoors will be severely injured. 
         Expect shattered windows, extensive damage to roofs, 
         siding, and vehicles.

This severe thunderstorm will remain over mainly rural areas of
northeastern Morrill County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 4171 10288 4184 10302 4200 10311 4200 10279
      4201 10278 4201 10269 4200 10267 4182 10268
TIME...MOT...LOC 0027Z 305DEG 23KT 4193 10289 

TORNADO...POSSIBLE
HAIL...4.00IN
WIND...60MPH
 
$$

Brothers

654 
WWUS55 KCYS 100041
SVSCYS

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

NEC123-100051-
/O.EXP.KCYS.SV.W.0090.000000T0000Z-210710T0045Z/
Morrill NE-
641 PM MDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MORRILL COUNTY
WILL EXPIRE AT 645 PM MDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
the Panhandle of Nebraska.

LAT...LON 4171 10288 4184 10302 4200 10311 4200 10279
      4201 10278 4201 10269 4200 10267 4182 10268
TIME...MOT...LOC 0041Z 305DEG 23KT 4188 10280 

$$

Brothers

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 2:20 PM MDT	Severe Thunderstorm Warning	CYS	Kimball	40 min
Jul 9, 2:51 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Kimball	39 min
Jul 9, 2:58 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball, Morrill	47 min
Jul 9, 3:32 PM MDT	Special Weather Statement	CYS	Sioux	28 min
Jul 9, 3:37 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne, Kimball	42 min
Jul 9, 3:54 PM MDT	Severe Thunderstorm Warning	CYS	Dawes, Sioux	36 min
Jul 9, 4:30 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes, Sioux	45 min
Jul 9, 5:08 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes	52 min
Jul 9, 5:42 PM MDT	Tornado Warning	CYS	Box Butte	33 min
Jul 9, 5:49 PM MDT	Areal Flood Advisory	CYS	Box Butte, Morrill	3 hr

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.