Alert archive / Wyoming / Tornado Warnings in 2015

Tornado Warning 5, NWS Cheyenne, WY

May 15, 2015Goshen County, Wyoming; Sioux County, Nebraska

NWS Cheyenne, WY issued this tornado warning at May 15, 2015, 4:00 PM MDT for Goshen County, Wyoming; Sioux County, Nebraska. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 15, 2015, 4:00 PM MDT (22:00 UTC)
Expired: May 15, 2015, 4:45 PM MDT
In force: 45 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Observed
Hail: 1.0 in

Counties Sioux County, NE, Goshen County, WY

The radar

The Cheyenne radar (KCYS), 121 km from the middle of the area, began a volume at 22:01 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 15, 12:58 PM MDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 10.0 hours before the alert went out and 241 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 484 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

320 
WFUS55 KCYS 152200
TORCYS
NEC165-WYC015-152245-
/O.NEW.KCYS.TO.W.0005.150515T2200Z-150515T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
400 PM MDT FRI MAY 15 2015

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN SIOUX COUNTY IN THE PANHANDLE OF NEBRASKA...
  EAST CENTRAL GOSHEN COUNTY IN SOUTHEASTERN WYOMING...

* UNTIL 445 PM MDT
    
* AT 359 PM MDT...A TORNADO PRODUCING STORM WAS LOCATED NEAR
  TORRINGTON...MOVING NORTHEAST AT 30 MPH.

  HAZARD...DAMAGING TORNADO AND QUARTER SIZE HAIL. 

  SOURCE...EMERGENCY MANAGEMENT CONFIRMED TORNADO. 

  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
  SOUTHWESTERN SIOUX AND EAST CENTRAL GOSHEN COUNTIES.

THIS REPLACES THE PREVIOUS TORNADO WARNING ISSUED FOR GOSHEN COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4193 10407 4208 10431 4243 10403 4213 10351
      4204 10397 4202 10404 4198 10407
TIME...MOT...LOC 2159Z 217DEG 25KT 4203 10407 

TORNADO...OBSERVED
HAIL...1.00IN

$$

RUBIN/HAHN

3 follow-up statements

354 
WWUS55 KCYS 152214
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
414 PM MDT FRI MAY 15 2015

WYC015-152224-
/O.CAN.KCYS.TO.W.0005.000000T0000Z-150515T2245Z/
GOSHEN WY-
414 PM MDT FRI MAY 15 2015

...THE TORNADO WARNING FOR EAST CENTRAL GOSHEN COUNTY IS CANCELLED...
    
THE TORNADIC THUNDERSTORM WHICH PROMPTED THE WARNING HAS MOVED OUT 
OF THE WARNED AREA. THEREFORE THE WARNING HAS BEEN CANCELLED FOR 
EAST CENTRAL GOSHEN COUNTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM MDT FOR CENTRAL
NEBRASKA.

LAT...LON 4243 10403 4213 10351 4204 10397 4203 10405
      4241 10405
TIME...MOT...LOC 2214Z 211DEG 25KT 4213 10400 

$$

NEC165-152245-
/O.CON.KCYS.TO.W.0005.000000T0000Z-150515T2245Z/
SIOUX NE-
414 PM MDT FRI MAY 15 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM MDT FOR
SOUTHWESTERN SIOUX COUNTY...
    
AT 414 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 10 MILES NORTHEAST OF TORRINGTON...MOVING NORTHEAST AT 30
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
SOUTHWESTERN SIOUX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 4243 10403 4213 10351 4204 10397 4203 10405
      4241 10405
TIME...MOT...LOC 2214Z 211DEG 25KT 4213 10400 

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

$$

RUBIN

614 
WWUS55 KCYS 152229
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
429 PM MDT FRI MAY 15 2015

NEC165-152245-
/O.CON.KCYS.TO.W.0005.000000T0000Z-150515T2245Z/
SIOUX NE-
429 PM MDT FRI MAY 15 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM MDT FOR
SOUTHWESTERN SIOUX COUNTY...
    
AT 429 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 15 MILES SOUTHWEST OF AGATE BED NATIONAL MONUMENT...OR 17
MILES NORTHEAST OF TORRINGTON...MOVING NORTHEAST AT 30 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
SOUTHWESTERN SIOUX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 4243 10403 4213 10351 4204 10397 4203 10405
      4241 10405
TIME...MOT...LOC 2229Z 217DEG 25KT 4222 10391 

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

$$

RUBIN

504 
WWUS55 KCYS 152242
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
442 PM MDT FRI MAY 15 2015

NEC165-152251-
/O.EXP.KCYS.TO.W.0005.000000T0000Z-150515T2245Z/
SIOUX NE-
442 PM MDT FRI MAY 15 2015

...THE TORNADO WARNING FOR SOUTHWESTERN SIOUX COUNTY WILL EXPIRE AT
445 PM MDT...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.  HOWEVER SMALL
HAIL....GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS
THUNDERSTORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM MDT FOR CENTRAL
NEBRASKA.

LAT...LON 4243 10403 4213 10351 4204 10397 4203 10405
      4241 10405
TIME...MOT...LOC 2238Z 217DEG 25KT 4222 10391 

$$

RUBIN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 1:22 AM MDT	Special Weather Statement	CYS	Goshen	38 min
May 15, 1:02 PM MDT	Special Weather Statement	CYS	Albany	43 min
May 15, 1:58 PM MDT	Special Weather Statement	CYS	Albany	47 min
May 15, 2:31 PM MDT	Special Weather Statement	CYS	Goshen	44 min
May 15, 2:50 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	30 min
May 15, 2:55 PM MDT	Special Weather Statement	CYS	Converse	35 min
May 15, 3:13 PM MDT	Special Weather Statement	CYS	Laramie	47 min
May 15, 3:18 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	57 min
May 15, 3:27 PM MDT	Special Weather Statement	CYS	Laramie	63 min
May 15, 3:32 PM MDT	Tornado Warning	CYS	Goshen	43 min
May 15, 4:04 PM MDT	Special Weather Statement	CYS	Goshen	26 min
May 15, 5:28 PM MDT	Areal Flood Advisory	CYS	Goshen	5 hr
May 15, 1:11 AM MDT	Special Weather Statement	CYS	Cheyenne	49 min
May 15, 2:40 AM MDT	Special Weather Statement	CYS	Morrill	50 min
May 15, 1:45 PM MDT	Special Weather Statement	CYS	Cheyenne	45 min
May 15, 1:50 PM MDT	Special Weather Statement	CYS	Cheyenne	40 min
May 15, 2:14 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball, Morrill	61 min
May 15, 2:33 PM MDT	Tornado Warning	CYS	Cheyenne, Morrill	42 min
May 15, 2:36 PM MDT	Special Weather Statement	CYS	Box Butte	39 min
May 15, 2:44 PM MDT	Special Weather Statement	CYS	Scotts Bluff	46 min
May 15, 2:47 PM MDT	Special Weather Statement	CYS	Dawes	43 min
May 15, 2:54 PM MDT	Special Weather Statement	CYS	Box Butte	51 min
May 15, 3:02 PM MDT	Special Weather Statement	CYS	Dawes	43 min
May 15, 3:11 PM MDT	Special Weather Statement	CYS	Morrill	49 min
May 15, 3:25 PM MDT	Severe Thunderstorm Warning	CYS	Morrill	65 min
May 15, 3:29 PM MDT	Special Weather Statement	CYS	Sioux	46 min
May 15, 4:14 PM MDT	Special Weather Statement	CYS	Kimball	31 min
May 15, 4:38 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne, Morrill	67 min
May 15, 4:52 PM MDT	Special Weather Statement	CYS	Morrill	38 min
May 15, 4:56 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte	40 min
May 15, 5:11 PM MDT	Special Weather Statement	CYS	Dawes	49 min
May 15, 5:17 PM MDT	Severe Thunderstorm Warning	CYS	Morrill	32 min
May 15, 5:33 PM MDT	Severe Thunderstorm Warning	CYS	Morrill	57 min
May 15, 5:45 PM MDT	Special Weather Statement	CYS	Sioux	45 min

Nearby

Tornado Warnings in Wyoming, 2015 Tornado Warnings in Nebraska, 2015 Every tornado warning in 2015 Tornadoes in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.