Alert archive / Wyoming / Tornado Warnings in 2020

Tornado Warning 5, NWS Cheyenne, WY

July 19, 2020Niobrara County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jul 19, 2020, 7:57 PM MDT for Niobrara County, Wyoming. It was in force for 33 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 19, 2020, 7:57 PM MDT (01:57 UTC)
Expired: Jul 19, 2020, 8:30 PM MDT
In force: 33 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 2.5 in

County Niobrara County, WY

The radar

The Cheyenne radar (KCYS), 193 km from the middle of the area, began a volume at 01:59 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 19, 8:15 PM MDT	HAIL 1.75	Lusk 0.6 S, WY	DURATION OF EVENT 15 MINUTES. PLENTY OF SHREDDED LEAVES, CAR DENTS, SHINGLES DAMAGED, AND BROKEN HOUSE WINDOWS. LATE REPORT.
Jul 19, 8:37 PM MDT	HAIL 1.75	Lusk, WY	PING PONG BALL AND GOLF BALL SIZE HAIL.
Jul 19, 8:40 PM MDT	HAIL 2	Lusk, WY	1.75 TO 2.00 INCH HAIL FALLING.

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 19, 4:06 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 2.0 hours before the alert went out and 191 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: 31 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 1904 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

215 
WFUS55 KCYS 200157
TORCYS
WYC027-200230-
/O.NEW.KCYS.TO.W.0005.200720T0157Z-200720T0230Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
757 PM MDT Sun Jul 19 2020

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  Southwestern Niobrara County in east central Wyoming...

* Until 830 PM MDT.
    
* At 757 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Lance Creek, or 15 miles northwest of Lusk, moving
  south at 30 mph.

  HAZARD...Tornado and tennis ball 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 dangerous storm will be near...
  Manville around 820 PM MDT.
  Lusk around 825 PM MDT.

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 4297 10476 4304 10451 4278 10422 4265 10467
TIME...MOT...LOC 0157Z 337DEG 26KT 4296 10459 

TORNADO...RADAR INDICATED
HAIL...2.50IN

$$

Brothers

2 follow-up statements

641 
WWUS55 KCYS 200207
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
807 PM MDT Sun Jul 19 2020

WYC027-200230-
/O.CON.KCYS.TO.W.0005.000000T0000Z-200720T0230Z/
Niobrara WY-
807 PM MDT Sun Jul 19 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM MDT FOR
SOUTHWESTERN NIOBRARA COUNTY...
    
At 806 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Manville, or 8 miles northwest of Lusk, moving south
at 35 mph.

HAZARD...Tornado and tennis ball 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 dangerous storm will be near...
  Manville around 810 PM MDT.
  Lusk around 820 PM MDT.

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 4295 10475 4302 10449 4278 10422 4265 10467
TIME...MOT...LOC 0206Z 338DEG 32KT 4286 10454 

TORNADO...RADAR INDICATED
HAIL...2.50IN

$$

Brothers

501 
WWUS55 KCYS 200219
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
819 PM MDT Sun Jul 19 2020

WYC027-200230-
/O.CON.KCYS.TO.W.0005.000000T0000Z-200720T0230Z/
Niobrara WY-
819 PM MDT Sun Jul 19 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM MDT FOR SOUTH
CENTRAL NIOBRARA COUNTY...
    
At 819 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Lusk, moving southeast at 25 mph.

HAZARD...Tornado and softball 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 dangerous storm will be near...
  Lusk around 825 PM MDT.

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 4291 10466 4297 10444 4278 10422 4267 10461
TIME...MOT...LOC 0219Z 336DEG 24KT 4282 10448 

TORNADO...RADAR INDICATED
HAIL...4.00IN

$$

Brothers

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 6:02 PM MDT	Severe Thunderstorm Warning	CYS	Converse, Niobrara	58 min
Jul 19, 6:44 PM MDT	Tornado Warning	CYS	Converse, Niobrara	31 min
Jul 19, 7:14 PM MDT	Severe Thunderstorm Warning	CYS	Converse, Niobrara	46 min
Jul 19, 7:24 PM MDT	Tornado Warning	CYS	Niobrara	36 min
Jul 19, 8:03 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	42 min
Jul 19, 8:14 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Niobrara	46 min
Jul 19, 8:30 PM MDT	Tornado Warning	CYS	Goshen, Niobrara	17 min
Jul 19, 8:45 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Niobrara	45 min
Jul 19, 9:39 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	51 min
Jul 20, 12:04 PM MDT	Special Weather Statement	CYS	Platte	26 min
Jul 20, 12:51 PM MDT	Special Weather Statement	CYS	Platte	24 min
Jul 20, 1:15 PM MDT	Special Weather Statement	CYS	Albany	30 min
Jul 20, 1:27 PM MDT	Special Weather Statement	CYS	Niobrara	33 min
Jul 20, 2:27 PM MDT	Special Weather Statement	CYS	Niobrara	33 min
Jul 20, 2:53 PM MDT	Special Weather Statement	CYS	Converse, Niobrara	52 min
Jul 20, 3:45 PM MDT	Special Weather Statement	CYS	Converse	45 min
Jul 20, 4:27 PM MDT	Special Weather Statement	CYS	Converse	48 min
Jul 20, 4:52 PM MDT	Severe Thunderstorm Warning	CYS	Converse	18 min
Jul 20, 5:05 PM MDT	Special Weather Statement	CYS	Platte	40 min
Jul 20, 5:13 PM MDT	Special Weather Statement	CYS	Niobrara	47 min
Jul 20, 5:14 PM MDT	Special Weather Statement	CYS	Niobrara	46 min
Jul 20, 5:16 PM MDT	Special Weather Statement	CYS	Converse	44 min
Jul 20, 5:41 PM MDT	Special Weather Statement	CYS	Laramie	49 min

Nearby

Tornado Warnings in Wyoming, 2020 Every tornado warning in 2020 Tornadoes in 2020

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.