Alert archive / Wyoming / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 68, NWS Cheyenne, WY

June 26, 2020Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 26, 2020, 4:43 PM MDT for Laramie County, Wyoming. It was in force for 47 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: Jun 26, 2020, 4:43 PM MDT (22:43 UTC)
Expired: Jun 26, 2020, 5:30 PM MDT
In force: 47 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 2.5 in
Wind: 60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 43 km from the middle of the area, began a volume at 22:44 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
Jun 26, 4:45 PM MDT	HAIL 1	2 Wnw Carpenter, WY
Jun 26, 4:45 PM MDT	HAIL 1.25	5 S Burns, WY
Jun 26, 4:56 PM MDT	HAIL 1.25	Carpenter, WY

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this severe thunderstorm warning; the first came 2 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.7 hours before the alert went out and 160 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: 108 J/kg
Mixed-layer CIN: -365 J/kg
Mixed-layer LCL: 1341 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

512 
WUUS55 KCYS 262243
SVRCYS
WYC021-262330-
/O.NEW.KCYS.SV.W.0068.200626T2243Z-200626T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
443 PM MDT Fri Jun 26 2020

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Southeastern Laramie County in southeastern Wyoming...

* Until 530 PM MDT.

* At 442 PM MDT, a severe thunderstorm was located near Carpenter, or
  20 miles east of Cheyenne, moving southeast at 25 mph.

  HAZARD...Tennis ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Carpenter around 455 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4104 10449 4113 10444 4107 10406 4100 10406
      4100 10437
TIME...MOT...LOC 2242Z 291DEG 21KT 4107 10440 

HAIL...2.50IN
WIND...60MPH
 
$$

Rubin

2 follow-up statements

383 
WWUS55 KCYS 262255
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
455 PM MDT Fri Jun 26 2020

WYC021-262330-
/O.CON.KCYS.SV.W.0068.000000T0000Z-200626T2330Z/
Laramie WY-
455 PM MDT Fri Jun 26 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM MDT
FOR SOUTHEASTERN LARAMIE COUNTY...

At 455 PM MDT, a severe thunderstorm was located just north of 
Carpenter, or 23 miles east of Cheyenne, moving southeast at 15 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
southeastern Laramie County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4102 10442 4112 10437 4107 10406 4100 10406
      4100 10437
TIME...MOT...LOC 2255Z 288DEG 15KT 4106 10435 

HAIL...1.75IN
WIND...60MPH
 
$$

Rubin

154 
WWUS55 KCYS 262330
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
530 PM MDT Fri Jun 26 2020

WYC021-262339-
/O.EXP.KCYS.SV.W.0068.000000T0000Z-200626T2330Z/
Laramie WY-
530 PM MDT Fri Jun 26 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LARAMIE COUNTY
WILL EXPIRE AT 530 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small
hail, gusty winds and heavy rain are still possible with this
thunderstorm.

LAT...LON 4102 10442 4112 10437 4107 10406 4100 10406
      4100 10437
TIME...MOT...LOC 2329Z 291DEG 21KT 4099 10411 

$$

Rubin

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Cheyenne, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 26, 1:35 PM MDT, 3 hours 8 minutes earlier.

Area forecast discussion, Jun 26, 1:35 PM MDT, 3 hours 8 minutes before

Area Forecast Discussion
National Weather Service Cheyenne WY
135 PM MDT Fri Jun 26 2020

.SHORT TERM...(This evening through Sunday night)
Issued at 135 PM MDT Fri Jun 26 2020

Tonight...The Storm Prediction Center outlook for marginal to slight
risk across our southeastern counties looks good through early
evening based on instability and shear parameters as well as the
HRRR prognosis. Though, the strongest storm development will likely
be across Colorado where better shear will exist. Will maintain a
chance of thunderstorms through this evening, with the greatest
chances across the southern Nebraska Panhandle.

Saturday...Thunderstorm chances should decrease as mid level
temperatures warm, leading to a stronger cap and limiting
thunderstorm chances. Still though, will forecast isolated
thunderstorms in the afternoon south of a Laramie to Alliance line.
Warmer temperatures as the 700 mb temperatures rise to near
14 Celsius.

Saturday night...Even more mild than tonight as the airmass
continues to warm.

Sunday/Sunday night...The flow aloft turns southwest and with enough
mid level moisture and strong daytime heating along a surface
trough, expect isolated to widely scattered afternoon and evening
thunderstorms focused mainly across southeast Wyoming. Even warmer
temperatures on tap with 700 mb temperatures near 15 Celsius. Even
warmer Sunday night as the airmass continues to modify.

.LONG TERM...(Monday through Friday)
Issued at 135 PM MDT Fri Jun 26 2020

Typical early summer weather expected over the cWa next week with
almost daily chances for afternoon and evening convection.
Activity will be aided by a slowly weakening upper trough that
will be over the northwestern part of the country. Most widespread
activity looks to occur Tuesday as a decent shortwave lifts
northeast across the region and pushes a cool front across the
CWA. Models in decent agreement with this scenario. Warming again
to close out the week with convection becoming more isolated.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday)
Issued at 1122 AM MDT Fri Jun 26 2020

Some cigs early this afternoon over far se Wy and the southern Neb
Panhandle close to 3 kft but should stay in VFR.  Wdly sctd showers
and storms expected again this afternoon and evening mainly over
southern areas close to the Colorado border with the area from KLAR
to KCYS to KSNY most likely to see these.  Gusty and erratic winds
and low visibilities in the stronger activity.  Clearing out later
this evening.

&&

.FIRE WEATHER...
Issued at 135 PM MDT Fri Jun 26 2020

Lower afternoon humidities Saturday through Monday will increase
concerns somewhat, then concerns will lessen Tuesday through
Wednesday as temperatures cool and humidities increase slightly.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

SHORT TERM...RUBIN
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...RUBIN

Hazardous weather outlook, Jun 26, 4:15 AM MDT, 12 hours 28 minutes before

Hazardous Weather Outlook
National Weather Service Cheyenne WY
415 AM MDT Fri Jun 26 2020

NEZ019>021-054-055-WYZ103-106>108-115>119-271015-
Scotts Bluff County-Banner County-Morrill-Kimball County-Cheyenne-
North Laramie Range-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-Laramie Valley-
South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
415 AM MDT Fri Jun 26 2020

This hazardous weather outlook is for the southern Nebraska
panhandle and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Scattered to numerous thunderstorms will develop early this
afternoon and push east into the plains. A few thunderstorms may
become strong to marginally severe and contain strong gusty winds
and hail.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

Thunderstorms are possible this weekend, but coverage will be more
isolated across southeast Wyoming. The probability for severe
weather is low.

.Spotter information statement...

Spotter activation is unlikely today.

WYZ104-105-109>114-271015-
Ferris/Seminoe/Shirley Mountains-Shirley Basin-
Central Carbon County-North Snowy Range Foothills-
Southwest Carbon County-Sierra Madre Range-
Upper North Platte River Basin-Snowy Range-
415 AM MDT Fri Jun 26 2020

This hazardous weather outlook is for south central Wyoming.

.DAY ONE...TODAY AND TONIGHT

Widely scattered thunderstorms are possible this afternoon. A few
thunderstorms may contain gusty winds and small hail.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

Thunderstorms will return to the region on Sunday as a strong
Pacific storm system moves towards the area.

.Spotter information statement...

Spotter activation will not be required.

NEZ002-003-095-096-WYZ101-102-271015-
Dawes-Box Butte-North Sioux-South Sioux-
Converse County Lower Elevations-Niobrara County-
415 AM MDT Fri Jun 26 2020

This hazardous weather outlook is for the northern Nebraska
panhandle and east central Wyoming.

.DAY ONE...TODAY AND TONIGHT

Isolated thunderstorms are expected today, especially along or
near the Pine Ridge east of Lusk. Thunderstorms should push east
of the area by this evening.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation will not be required.

In the hours before

Local storm report, Jun 26, 4:11 PM MDT, 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
411 PM MDT FRI JUN 26 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0350 PM     HAIL             2 NNE CHEYENNE          41.17N 104.78W
06/26/2020  M1.25 INCH       LARAMIE            WY   PUBLIC

&&

AW

Local storm report, Jun 26, 4:16 PM MDT, 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
416 PM MDT FRI JUN 26 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0355 PM     HAIL             5 NE CHEYENNE           41.20N 104.72W
06/26/2020  M0.50 INCH       LARAMIE            WY   TRAINED SPOTTER

&&

Local storm report, Jun 26, 4:17 PM MDT, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
417 PM MDT FRI JUN 26 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     HAIL             8 WSW HILLSDALE         41.16N 104.63W
06/26/2020  M0.88 INCH       LARAMIE            WY   EMERGENCY MNGR

&&

AW

Local storm report, Jun 26, 4:22 PM MDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
422 PM MDT FRI JUN 26 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0403 PM     HAIL             2 N CHEYENNE            41.17N 104.79W
06/26/2020  M1.00 INCH       LARAMIE            WY   EMERGENCY MNGR

            NEAR ANDERSON ELEMENTARY SCHOOL.

&&

AW

Local storm report, Jun 26, 4:27 PM MDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
427 PM MDT FRI JUN 26 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0414 PM     HAIL             2 NNE WARREN AF BASE    41.18N 104.84W
06/26/2020  E1.00 INCH       LARAMIE            WY   PUBLIC

            VIA TWITTER.

&&

AW

Local storm report, Jun 26, 4:36 PM MDT, 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
436 PM MDT FRI JUN 26 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0350 PM     HAIL             5 NE CHEYENNE           41.20N 104.72W
06/26/2020  M1.00 INCH       LARAMIE            WY   PUBLIC

            CREST RIDGE SUBDIVISION.

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 25, 6:10 PM MDT	Special Weather Statement	CYS	Laramie	35 min
Jun 25, 6:16 PM MDT	Special Weather Statement	CYS	Albany	29 min
Jun 25, 7:06 PM MDT	Special Weather Statement	CYS	Albany	54 min
Jun 26, 1:10 PM MDT	Special Weather Statement	CYS	Laramie	50 min
Jun 26, 2:07 PM MDT	Special Weather Statement	CYS	Laramie	38 min
Jun 26, 2:30 PM MDT	Severe Thunderstorm Warning	CYS	Albany, Laramie	60 min
Jun 26, 3:28 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	47 min
Jun 26, 4:07 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	38 min
Jun 26, 5:02 PM MDT	Special Weather Statement	CYS	Platte	58 min
Jun 26, 5:10 PM MDT	Severe Thunderstorm Warning	CYS	Platte	21 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2020 Every severe thunderstorm warning 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.