Alert archive / Wyoming / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 67, NWS Cheyenne, WY

June 25, 2012Converse County, Niobrara County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 25, 2012, 3:36 PM MDT for Converse County, Niobrara County, Wyoming. It was in force for 54 min. 2 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: Jun 25, 2012, 3:36 PM MDT (21:36 UTC)
Expired: Jun 25, 2012, 4:30 PM MDT
In force: 54 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 70.0 mph

Counties Converse County, WY, Niobrara County, WY

The radar

The Rapid City radar (KUDX), 191 km from the middle of the area, began a volume at 21:39 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
Jun 25, 3:43 PM MDT	HAIL 1	Bill, WY	RANGED FROM 3/4 INCH TO 1 INCH.
Jun 25, 4:00 PM MDT	HAIL 1	7 Nne Bill, WY	HAIL RANGED FROM 1/2 TO 1 INCH.

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
Jun 25, 3:07 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 9.6 hours before the alert went out and 185 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: 2066 J/kg
Mixed-layer CIN: -369 J/kg
Mixed-layer LCL: 611 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 56 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.

752 
WUUS55 KCYS 252136
SVRCYS
WYC009-027-252230-
/O.NEW.KCYS.SV.W.0067.120625T2136Z-120625T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
336 PM MDT MON JUN 25 2012

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CONVERSE COUNTY IN EAST CENTRAL WYOMING...
  NORTHWESTERN NIOBRARA COUNTY IN EAST CENTRAL WYOMING...

* UNTIL 430 PM MDT

* AT 332 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR
  BILL...OR 32 MILES NORTH OF DOUGLAS...AND MOVING NORTHEAST AT 25
  MPH.

* LOCATIONS IMPACTED INCLUDE...
  DULL CENTER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE
HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

&&

LAT...LON 4344 10460 4311 10526 4322 10545 4350 10515
      4351 10476
TIME...MOT...LOC 2136Z 221DEG 21KT 4324 10527
WIND...HAIL 70MPH 1.00IN

$$

CLAYCOMB

3 follow-up statements

363 
WWUS55 KCYS 252147
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
347 PM MDT MON JUN 25 2012

WYC009-027-252230-
/O.CON.KCYS.SV.W.0067.000000T0000Z-120625T2230Z/
NIOBRARA WY-CONVERSE WY-
347 PM MDT MON JUN 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHEASTERN
CONVERSE AND NORTHWESTERN NIOBRARA COUNTIES UNTIL 430 PM MDT...

AT 344 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR
BILL...OR 37 MILES NORTH OF DOUGLAS...MOVING NORTHEAST AT 25 MPH.

IN ADDITION...AT 343 PM...QUARTER SIZED HAIL WAS REPORTED AT BILL  
WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  DULL CENTER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DAMAGING WINDS IF YOU ARE IN
THE PATH OF THIS STORM. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

&&

LAT...LON 4344 10460 4311 10526 4322 10545 4350 10515
      4351 10476
TIME...MOT...LOC 2147Z 221DEG 21KT 4329 10521
WIND...HAIL 70MPH 1.00IN

$$

CLAYCOMB

910 
WWUS55 KCYS 252205
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
405 PM MDT MON JUN 25 2012

WYC009-027-252230-
/O.CON.KCYS.SV.W.0067.000000T0000Z-120625T2230Z/
NIOBRARA WY-CONVERSE WY-
405 PM MDT MON JUN 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHEASTERN
CONVERSE AND NORTHWESTERN NIOBRARA COUNTIES UNTIL 430 PM MDT...

AT 401 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED 10
MILES SOUTHWEST OF DULL CENTER...OR 43 MILES NORTH OF DOUGLAS...
MOVING NORTHEAST AT 25 MPH.

IN ADDITION...AT 4 PM QUARTER SIZED HAIL WAS REPORTED 7 MILES NORTH 
NORTHEAST OF BILL WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  DULL CENTER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DAMAGING WINDS IF YOU ARE IN
THE PATH OF THIS STORM. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

&&

LAT...LON 4344 10460 4323 10504 4333 10532 4350 10515
      4351 10476
TIME...MOT...LOC 2205Z 221DEG 21KT 4337 10511
WIND...HAIL 70MPH 1.00IN

$$

CLAYCOMB

480 
WWUS55 KCYS 252223
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
423 PM MDT MON JUN 25 2012

WYC009-027-252233-
/O.EXP.KCYS.SV.W.0067.000000T0000Z-120625T2230Z/
NIOBRARA WY-CONVERSE WY-
423 PM MDT MON JUN 25 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CONVERSE AND
NORTHWESTERN NIOBRARA COUNTIES WILL EXPIRE AT 430 PM MDT...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 11 PM THIS EVENING.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

LAT...LON 4344 10460 4323 10504 4333 10532 4350 10515
      4351 10476
TIME...MOT...LOC 2223Z 221DEG 21KT 4345 10501

$$

CLAYCOMB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 24, 6:57 PM MDT	Special Weather Statement	CYS	Niobrara	18 min
Jun 24, 7:35 PM MDT	Special Weather Statement	CYS	Laramie	25 min
Jun 24, 9:52 PM MDT	Special Weather Statement	CYS	Laramie	23 min
Jun 24, 11:00 PM MDT	Special Weather Statement	CYS	Laramie	15 min
Jun 25, 12:05 AM MDT	Special Weather Statement	CYS	Laramie	40 min
Jun 25, 12:24 AM MDT	Special Weather Statement	CYS	Laramie	66 min
Jun 25, 4:55 AM MDT	Red Flag Warning	CYS		4 days
Jun 25, 1:18 PM MDT	Special Weather Statement	CYS	Albany	57 min
Jun 25, 1:43 PM MDT	Severe Thunderstorm Warning	CYS	Albany, Platte	41 min
Jun 25, 2:42 PM MDT	Severe Thunderstorm Warning	CYS	Converse	36 min
Jun 25, 2:50 PM MDT	Severe Thunderstorm Warning	CYS	Converse	24 min
Jun 25, 3:11 PM MDT	Severe Thunderstorm Warning	CYS	Converse, Niobrara	64 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2012 Every severe thunderstorm warning in 2012

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.