Alert archive / Nebraska / Tornado Warnings in 2016

Tornado Warning 18, NWS Cheyenne, WY

September 23, 2016Sioux County, Nebraska

NWS Cheyenne, WY issued this tornado warning at Sep 23, 2016, 5:17 PM MDT for Sioux County, Nebraska. It was in force for 28 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: Sep 23, 2016, 5:17 PM MDT (23:17 UTC)
Expired: Sep 23, 2016, 5:45 PM MDT
In force: 28 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Sioux County, NE

The radar

The Rapid City radar (KUDX), 178 km from the middle of the area, began a volume at 23:17 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
Sep 23, 5:25 PM MDT	TSTM WND GST 60	Harrison, NE	AT LEAST 60 MPH WIND GUSTS AND DIME SIZED HAIL. VERY STRONG ROTATION OBSERVED WITH A POSSIBLE FUNNEL CLOUD SOUTH OF HARRISON A FEW MINUTES EARLIER.
Sep 23, 5:30 PM MDT	HAIL 1	4 Ne Harrison, NE
Sep 23, 5:35 PM MDT	HAIL 1.75	9 Ne Harrison, NE	PEA TO GOLFBALL SIZED HAIL COVERING GROUND. POWER OUT FOR ABOUT 4 HOURS DURING THE AFTERNOON.

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
Sep 23, 2:21 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 11.3 hours before the alert went out and 171 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: 3 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 468 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

As transmitted.

998 
WFUS55 KCYS 232317
TORCYS
NEC165-232345-
/O.NEW.KCYS.TO.W.0018.160923T2317Z-160923T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
517 PM MDT FRI SEP 23 2016

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN SIOUX COUNTY IN THE PANHANDLE OF NEBRASKA...

* UNTIL 545 PM MDT
    
* AT 517 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED OVER HARRISON...OR 27 MILES EAST OF
  LUSK...MOVING NORTHEAST AT 35 MPH.

  HAZARD...TORNADO AND QUARTER SIZE HAIL. 

  SOURCE...RADAR INDICATED ROTATION. 

  IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
           SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED.
           DAMAGE TO ROOFS...WINDOWS...AND VEHICLES WILL OCCUR. TREE
           DAMAGE IS LIKELY. 

* THIS TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
  NORTHWESTERN SIOUX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF YOU ARE OUTDOORS...IN
A MOBILE HOME...OR IN A VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4259 10391 4264 10401 4291 10388 4283 10364
TIME...MOT...LOC 2317Z 209DEG 32KT 4267 10392 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

HAMMER

2 follow-up statements

956 
WWUS55 KCYS 232331
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
531 PM MDT FRI SEP 23 2016

NEC165-232345-
/O.CON.KCYS.TO.W.0018.000000T0000Z-160923T2345Z/
SIOUX NE-
531 PM MDT FRI SEP 23 2016

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 545 PM MDT FOR
NORTHWESTERN SIOUX COUNTY...
    
AT 530 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 7 MILES NORTH OF HARRISON...OR 30 MILES EAST OF LUSK...
MOVING NORTHEAST AT 35 MPH.

HAZARD...TORNADO AND QUARTER SIZE HAIL. 

SOURCE...RADAR INDICATED ROTATION. THIS STORM HAS A HISTORY OF
         PRODUCING FUNNEL CLOUDS. A TORNADO MAY DEVELOP AT ANY TIME. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE
         TO ROOFS...WINDOWS...AND VEHICLES WILL OCCUR.  TREE DAMAGE
         IS LIKELY. 

THIS TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
NORTHWESTERN SIOUX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF YOU ARE OUTDOORS...IN
A MOBILE HOME...OR IN A VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4268 10381 4274 10396 4291 10388 4283 10364
TIME...MOT...LOC 2330Z 206DEG 32KT 4280 10386 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

HAMMER

862 
WWUS55 KCYS 232340
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
540 PM MDT FRI SEP 23 2016

NEC165-232350-
/O.EXP.KCYS.TO.W.0018.000000T0000Z-160923T2345Z/
SIOUX NE-
540 PM MDT FRI SEP 23 2016

...THE TORNADO WARNING FOR NORTHWESTERN SIOUX COUNTY WILL EXPIRE AT
545 PM MDT...
    
THE TORNADO THREAT HAS DIMINISHED AND THE TORNADO WARNING HAS BEEN
CANCELLED. HOWEVER...LARGE HAIL AND DAMAGING WINDS REMAIN LIKELY AND
A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR THE AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 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 4268 10381 4274 10396 4291 10388 4283 10364
TIME...MOT...LOC 2339Z 209DEG 32KT 4280 10386 

$$

HAMMER

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 23, 3:27 PM MDT	Special Weather Statement	CYS	Sioux	48 min
Sep 23, 3:43 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes, Sioux	47 min
Sep 23, 4:20 PM MDT	Severe Thunderstorm Warning	CYS	Dawes	38 min
Sep 23, 5:01 PM MDT	Severe Thunderstorm Warning	CYS	Dawes, Sioux	44 min
Sep 23, 5:06 PM MDT	Special Weather Statement	CYS	Banner, Box Butte, Kimball, Scotts Bluff	39 min

Nearby

Tornado Warnings in Nebraska, 2016 Every tornado warning in 2016 Tornadoes in 2016

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.