Alert archive / Wyoming / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 49, NWS Cheyenne, WY

June 27, 2017Albany County, Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 27, 2017, 5:40 PM MDT for Albany County, Laramie County, Platte County, Wyoming. It was in force for 42 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
Jun 27, 2017, 5:40 PM MDT (23:40 UTC)
Expired
Jun 27, 2017, 6:22 PM MDT
In force
42 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Albany County, WY, Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 66 km from the middle of the area, began a volume at 23:41 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 nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 11.7 hours before the alert went out and 258 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-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2017-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2017-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
34 J/kg
Mixed-layer CIN
-526 J/kg
Mixed-layer LCL
2742 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

861 
WUUS55 KCYS 272340
SVRCYS
WYC001-021-031-280045-
/O.NEW.KCYS.SV.W.0049.170627T2340Z-170628T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
540 PM MDT TUE JUN 27 2017

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Southeastern Albany County in southeastern Wyoming...
  Northwestern Laramie County in southeastern Wyoming...
  Southwestern Platte County in southeastern Wyoming...

* Until 645 PM MDT

* At 539 PM MDT, a severe thunderstorm was located near Horse Creek,
  or 15 miles east of Laramie, moving east at 40 mph.

  HAZARD...70 mph wind gusts. 

  SOURCE...Radar indicated. At 522 pm MDT...A peak wind gust to 90 
           mph was reported at the Laramie Airport. 

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings. 

* This severe thunderstorm will be near, 
  Horse Creek around 550 PM MDT. 

This includes Interstate 80 in Wyoming between mile markers 299 and
326.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4111 10583 4178 10579 4182 10505 4126 10505
TIME...MOT...LOC 2339Z 261DEG 34KT 4138 10530 

HAIL...<.75IN
WIND...70MPH
 
$$

Rubin
2 follow-up statements
364 
WWUS55 KCYS 272356
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
556 PM MDT TUE JUN 27 2017

WYC001-021-031-280045-
/O.CON.KCYS.SV.W.0049.000000T0000Z-170628T0045Z/
Albany WY-Laramie WY-Platte WY-
556 PM MDT TUE JUN 27 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR SOUTHEASTERN ALBANY...NORTHWESTERN LARAMIE AND SOUTHWESTERN
PLATTE COUNTIES...

At 556 PM MDT, a severe thunderstorm was located near Horse Creek, or
23 miles northwest of Cheyenne, moving east at 40 mph.

HAZARD...70 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

this severe thunderstorm will remain over mainly rural areas of
southeastern Albany...northwestern Laramie and southwestern Platte
Counties.

This includes Interstate 80 in Wyoming between mile markers 315 and
326.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4116 10559 4179 10551 4182 10505 4126 10505
TIME...MOT...LOC 2356Z 261DEG 34KT 4141 10508 

HAIL...<.75IN
WIND...70MPH
 
$$

Rubin
261 
WWUS55 KCYS 280022
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
622 PM MDT TUE JUN 27 2017

WYC001-021-031-280032-
/O.CAN.KCYS.SV.W.0049.000000T0000Z-170628T0045Z/
Albany WY-Laramie WY-Platte WY-
622 PM MDT TUE JUN 27 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ALBANY...
NORTHWESTERN LARAMIE AND SOUTHWESTERN PLATTE COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning has been cancelled.

LAT...LON 4116 10559 4179 10551 4182 10505 4126 10505
TIME...MOT...LOC 0020Z 261DEG 34KT 4145 10476 

$$

Rubin

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 27, 12:47 PM MDTRed Flag WarningCYS6 hr
Jun 27, 1:13 PM MDTSpecial Weather StatementCYSLaramie47 min
Jun 27, 2:40 PM MDTSpecial Weather StatementCYSConverse50 min
Jun 27, 3:14 PM MDTSpecial Weather StatementCYSNiobrara46 min
Jun 27, 3:35 PM MDTSpecial Weather StatementCYSNiobrara40 min
Jun 27, 3:57 PM MDTSpecial Weather StatementCYSNiobrara48 min
Jun 27, 4:54 PM MDTSpecial Weather StatementCYSConverse51 min
Jun 27, 5:24 PM MDTSpecial Weather StatementCYSAlbany51 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2017Every severe thunderstorm warning in 2017

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.