Alert archive / Wyoming / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 21, NWS Riverton, WY

June 7, 2020Fremont County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 7, 2020, 2:42 PM MDT for Fremont County, Wyoming. It was in force for 33 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 7, 2020, 2:42 PM MDT (20:42 UTC)
Expired: Jun 7, 2020, 3:15 PM MDT
In force: 33 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Fremont County, WY

The radar

The Riverton/Lander radar (KRIW), 54 km from the middle of the area, began a volume at 20:45 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 12:00Z, 8.7 hours before the alert went out and 57 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: 1737 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

181 
WUUS55 KRIW 072042
SVRRIW
WYC013-072115-
/O.NEW.KRIW.SV.W.0021.200607T2042Z-200607T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Riverton WY
242 PM MDT Sun Jun 7 2020

The National Weather Service in Riverton has issued a

* Severe Thunderstorm Warning for...
  Southeastern Fremont County in central Wyoming...

* Until 315 PM MDT.

* At 242 PM MDT, a severe thunderstorm was located over Sinks Canyon
  State Park, which is 8 miles south of Lander, moving northeast at
  55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Lander and Milford around 250 PM MDT.
  Hudson around 300 PM MDT.
  Arapahoe around 305 PM MDT.

Other locations impacted by this severe thunderstorm include 
Atlantic City, Sinks Canyon Campground, and Lander Hunt Field.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4242 10883 4256 10907 4269 10907 4269 10910
      4304 10892 4293 10803 4230 10829
TIME...MOT...LOC 2042Z 211DEG 48KT 4272 10878 

HAIL...<.75IN
WIND...60MPH
 
$$

CNJ

2 follow-up statements

870 
WWUS55 KRIW 072102
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
302 PM MDT Sun Jun 7 2020

WYC013-072115-
/O.CON.KRIW.SV.W.0021.000000T0000Z-200607T2115Z/
Fremont-
302 PM MDT Sun Jun 7 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM MDT
FOR SOUTHEASTERN FREMONT COUNTY...

At 301 PM MDT, a severe thunderstorm was located over Lander, moving
northeast at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

This severe storm will be near...
  Hudson around 310 PM MDT.
  Arapahoe around 320 PM MDT.

Wind gusts near 50 mph were reported at Lander Hunt Field just 
before 3 PM. Gusts above 60 mph have been measured on Highway 28 
around Red Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4253 10877 4265 10896 4271 10903 4276 10906
      4304 10892 4293 10803 4245 10823 4249 10855
TIME...MOT...LOC 2101Z 210DEG 31KT 4287 10870 

HAIL...<.75IN
WIND...60MPH
 
$$

CNJ

117 
WWUS55 KRIW 072114
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
314 PM MDT Sun Jun 7 2020

WYC013-072122-
/O.EXP.KRIW.SV.W.0021.000000T0000Z-200607T2115Z/
Fremont-
314 PM MDT Sun Jun 7 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN FREMONT COUNTY
WILL EXPIRE AT 315 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty 
winds of 40 to 50 mph are still possible with this thunderstorm as 
it rumbles through central Fremont County.

A wind gust to 47 mph was reported at Lander Hunt Field and gusts in 
excess of 60 mph were recorded along Highway 28 around Red Canyon 
just before 3 PM.

LAT...LON 4253 10877 4265 10896 4271 10903 4276 10906
      4304 10892 4293 10803 4245 10823 4249 10855
TIME...MOT...LOC 2112Z 211DEG 48KT 4299 10860 

$$

CNJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 6, 6:10 PM MDT	Special Weather Statement	RIW	Fremont	35 min
Jun 6, 6:22 PM MDT	Special Weather Statement	RIW	Teton	23 min
Jun 7, 2:22 AM MDT	Winter Weather Advisory	RIW	Fremont, Lincoln, Park, Sublette, Teton	30 hr
Jun 7, 2:30 AM MDT	Freeze Watch	RIW	Fremont, Lincoln, Sublette, Sweetwater, Teton	9 hr
Jun 7, 11:15 AM MDT	Freeze Warning	RIW	Fremont, Lincoln, Sublette, Sweetwater, Teton	22 hr
Jun 7, 11:57 AM MDT	Special Weather Statement	RIW	Uinta	33 min
Jun 7, 12:10 PM MDT	Special Weather Statement	RIW	Lincoln, Sublette	65 min
Jun 7, 12:15 PM MDT	Special Weather Statement	RIW	Lincoln, Sublette	60 min
Jun 7, 12:25 PM MDT	Severe Thunderstorm Warning	RIW	Lincoln	33 min
Jun 7, 12:39 PM MDT	Special Weather Statement	RIW		36 min
Jun 7, 1:09 PM MDT	Special Weather Statement	RIW	Sublette	51 min
Jun 7, 1:27 PM MDT	Special Weather Statement	RIW		48 min
Jun 7, 1:52 PM MDT	Special Weather Statement	RIW		53 min
Jun 7, 2:11 PM MDT	Special Weather Statement	RIW	Fremont	49 min
Jun 7, 2:22 PM MDT	Special Weather Statement	RIW	Sweetwater	38 min
Jun 7, 2:25 PM MDT	Special Weather Statement	RIW	Natrona	65 min
Jun 7, 3:35 PM MDT	Special Weather Statement	RIW	Fremont	55 min
Jun 7, 4:13 PM MDT	Special Weather Statement	RIW		32 min
Jun 7, 4:20 PM MDT	Special Weather Statement	RIW	Washakie	55 min
Jun 7, 5:06 PM MDT	Special Weather Statement	RIW	Natrona	24 min
Jun 7, 5:23 PM MDT	Special Weather Statement	RIW		37 min
Jun 7, 5:32 PM MDT	Special Weather Statement	RIW	Natrona	28 min
Jun 7, 5:55 PM MDT	Special Weather Statement	RIW	Natrona	35 min
Jun 7, 5:59 PM MDT	Special Weather Statement	RIW	Natrona	31 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.