Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 5, NWS Riverton, WY

July 5, 2021Natrona County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jul 5, 2021, 6:50 PM MDT for Natrona County, Wyoming. It was in force for 40 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
Jul 5, 2021, 6:50 PM MDT (00:50 UTC)
Expired
Jul 5, 2021, 7:30 PM MDT
In force
40 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 111 km from the middle of the area, began a volume at 00:48 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

Riverton, WY (KRIW), launched 00:00Z, 0.8 hours before the alert went out and 105 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, Riverton, WY at 00:00Z on 2021-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 00:00Z on 2021-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3563 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
264 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.4

Open this sounding in Storm Lab

The text

As transmitted.

696 
WUUS55 KRIW 060050
SVRRIW
WYC025-060130-
/O.NEW.KRIW.SV.W.0005.210706T0050Z-210706T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Riverton WY
650 PM MDT Mon Jul 5 2021

The National Weather Service in Riverton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Natrona County in central Wyoming...

* Until 730 PM MDT.

* At 650 PM MDT, severe thunderstorms were located along a line
  extending from 6 miles west of Ervay to 13 miles northeast of Split
  Rock to 6 miles north of Muddy Gap, moving east at 30 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Ervay around 700 PM MDT.
  Devil's Gate around 710 PM MDT.

Other locations in the path of these severe thunderstorms include
Independence Rock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with these storms. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4243 10695 4243 10754 4278 10754 4278 10750
      4292 10750 4298 10699 4265 10687
TIME...MOT...LOC 0050Z 260DEG 27KT 4285 10749 4260 10738 4247 10743 

HAIL...1.00IN
WIND...60MPH
 
$$

VandenBoogart
2 follow-up statements
963 
WWUS55 KRIW 060114
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
714 PM MDT Mon Jul 5 2021

WYC025-060130-
/O.CON.KRIW.SV.W.0005.000000T0000Z-210706T0130Z/
Natrona-
714 PM MDT Mon Jul 5 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM MDT
FOR SOUTHWESTERN NATRONA COUNTY...

At 713 PM MDT, severe thunderstorms were located along a line
extending from near Ervay to 9 miles north of Independence Rock to
near Devil's Gate, moving east at 30 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe thunderstorms will remain over mainly rural areas of
southwestern Natrona County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4243 10747 4261 10742 4278 10750 4285 10750
      4293 10741 4298 10699 4265 10687 4243 10695
TIME...MOT...LOC 0113Z 260DEG 27KT 4288 10727 4263 10716 4250 10721 

HAIL...0.75IN
WIND...60MPH
 
$$

VandenBoogart
334 
WWUS55 KRIW 060127
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
727 PM MDT Mon Jul 5 2021

WYC025-060136-
/O.EXP.KRIW.SV.W.0005.000000T0000Z-210706T0130Z/
Natrona-
727 PM MDT Mon Jul 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN NATRONA COUNTY
WILL EXPIRE AT 730 PM MDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

LAT...LON 4243 10747 4261 10742 4278 10750 4285 10750
      4293 10741 4298 10699 4265 10687 4243 10695
TIME...MOT...LOC 0126Z 260DEG 27KT 4290 10715 4265 10704 4252 10709 

$$

VandenBoogart

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 5, 6:34 PM MDTSpecial Weather StatementRIW26 min
Jul 5, 7:01 PM MDTSpecial Weather StatementRIWNatrona29 min
Jul 5, 7:35 PM MDTSpecial Weather StatementRIWNatrona40 min
Jul 6, 1:38 PM MDTFire Weather WatchRIWLincoln, Sublette, Sweetwater, Uinta24 hr
Jul 6, 5:04 PM MDTSpecial Weather StatementRIWHot Springs26 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2021Every severe thunderstorm warning in 2021

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.