Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 87, NWS Cheyenne, WY

July 9, 2021Dawes County, Sioux County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 9, 2021, 3:54 PM MDT for Dawes County, Sioux County, Nebraska. It was in force for 36 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: Jul 9, 2021, 3:54 PM MDT (21:54 UTC)
Expired: Jul 9, 2021, 4:30 PM MDT
In force: 36 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Possible
Hail: 1.5 in
Wind: 60.0 mph

Counties Dawes County, NE, Sioux County, NE

The radar

The Rapid City radar (KUDX), 181 km from the middle of the area, began a volume at 21:55 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, 4:00 PM MDT	HAIL 1.75	10 E Harrison, 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

Rapid City, SD (KUNR), launched 12:00Z, 9.9 hours before the alert went out and 174 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: 766 J/kg
Mixed-layer CIN: -307 J/kg
Mixed-layer LCL: 1363 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

754 
WUUS55 KCYS 092154
SVRCYS
NEC045-165-092230-
/O.NEW.KCYS.SV.W.0087.210709T2154Z-210709T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
354 PM MDT Fri Jul 9 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Southwestern Dawes County in the Panhandle of Nebraska...
  Central Sioux County in the Panhandle of Nebraska...

* Until 430 PM MDT.

* At 353 PM MDT, a severe thunderstorm was located 7 miles east of
  Harrison, or 36 miles east of Lusk, moving southeast at 35 mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* Locations impacted include...
  Fort Robinson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4267 10389 4279 10373 4256 10327 4237 10356
TIME...MOT...LOC 2153Z 313DEG 30KT 4268 10374 

TORNADO...POSSIBLE
HAIL...1.50IN
WIND...60MPH
 
$$

Brothers

1 follow-up statement

900 
WWUS55 KCYS 092209
SVSCYS

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

NEC045-165-092230-
/O.CON.KCYS.SV.W.0087.000000T0000Z-210709T2230Z/
Dawes NE-Sioux NE-
409 PM MDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR SOUTHWESTERN DAWES AND EAST CENTRAL SIOUX COUNTIES...

At 407 PM MDT, a severe thunderstorm was located 8 miles southwest of
Fort Robinson Campground, or 35 miles southwest of Chadron, moving 
southeast at 35 mph. Trained weather spotters reported golf ball 
size hail east of Harrison at 400 PM MDT. 

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
southwestern Dawes and east central Sioux Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4262 10381 4274 10366 4256 10327 4237 10356
TIME...MOT...LOC 2207Z 313DEG 30KT 4260 10362 

TORNADO...POSSIBLE
HAIL...1.75IN
WIND...60MPH
 
$$

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, 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
Jul 9, 5:58 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Morrill	47 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.