Alert archive / Wyoming / Tornado Warnings in 2018

Tornado Warning 4, NWS Riverton, WY

May 27, 2018Fremont County, Sweetwater County, Wyoming

NWS Riverton, WY issued this tornado warning at May 27, 2018, 2:13 PM MDT for Fremont County, Sweetwater County, Wyoming. It was in force for 47 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
May 27, 2018, 2:13 PM MDT (20:13 UTC)
Expired
May 27, 2018, 3:00 PM MDT
In force
47 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

Counties Fremont County, WY, Sweetwater County, WY

The radar

The Riverton/Lander radar (KRIW), 113 km from the middle of the area, began a volume at 20:16 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 27, 12:05 PM MDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 8.2 hours before the alert went out and 110 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 12:00Z on 2018-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 52 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, Riverton, WY at 12:00Z on 2018-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
52 J/kg
Mixed-layer CIN
-196 J/kg
Mixed-layer LCL
1809 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

474 
WFUS55 KRIW 272013
TORRIW
WYC013-037-272100-
/O.NEW.KRIW.TO.W.0004.180527T2013Z-180527T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Riverton WY
213 PM MDT SUN MAY 27 2018

The National Weather Service in Riverton has issued a

* Tornado Warning for...
  Southeastern Fremont County in central Wyoming...
  Northeastern Sweetwater County in south central Wyoming...

* Until 300 PM MDT
    
* At 212 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 13 miles southwest of Bairoil, which is 21 miles south
  of Jeffrey City, moving north at 15 mph.

  HAZARD...Tornado and ping pong ball size hail. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* This dangerous storm will be near...
  Crooks Gap around 300 PM MDT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4208 10761 4208 10793 4240 10799 4240 10758
TIME...MOT...LOC 2012Z 177DEG 15KT 4216 10780 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

Jones
2 follow-up statements
385 
WWUS55 KRIW 272041
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
241 PM MDT SUN MAY 27 2018

WYC013-037-272100-
/O.CON.KRIW.TO.W.0004.000000T0000Z-180527T2100Z/
Fremont-Sweetwater-
241 PM MDT SUN MAY 27 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM MDT FOR
SOUTHEASTERN FREMONT AND NORTHEASTERN SWEETWATER COUNTIES...
    
At 239 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Crooks Gap, which is 14 miles south of Jeffrey City,
moving northwest at 20 mph.

HAZARD...Tornado and ping pong ball size hail. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This dangerous storm will be near...
  Crooks Gap around 255 PM MDT. 

Additional thunderstorms are developing north of this thunderstorm. 
These new storms may also pose a tornado threat Sunday afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4215 10761 4215 10794 4240 10799 4240 10758
TIME...MOT...LOC 2039Z 155DEG 17KT 4228 10788 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

CNJ
578 
WWUS55 KRIW 272057
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
257 PM MDT SUN MAY 27 2018

WYC013-037-272105-
/O.EXP.KRIW.TO.W.0004.000000T0000Z-180527T2100Z/
Fremont-Sweetwater-
257 PM MDT SUN MAY 27 2018

...THE TORNADO WARNING FOR SOUTHEASTERN FREMONT AND NORTHEASTERN
SWEETWATER COUNTIES WILL EXPIRE AT 300 PM MDT...
                
The storm which prompted the warning has weakened and is no longer 
appears capable of producing a tornado. Therefore the warning will 
be allowed to expire at 300 PM.

However, one-quarter to one-half inch diameter hail and very heavy 
rain are still likely with any thunderstorms this afternoon.

A severe thunderstorm watch remains in effect until 800 PM MDT for
central Wyoming.

LAT...LON 4215 10761 4215 10794 4240 10799 4240 10758
TIME...MOT...LOC 2055Z 177DEG 15KT 4233 10788 

$$

CNJ

The office that day

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

IssuedProductOfficeCountiesLasted
May 26, 6:49 PM MDTSpecial Weather StatementRIWPark41 min
May 26, 11:00 PM MDTAreal Flood WarningRIWBig Horn12 hr
May 26, 11:21 PM MDTAreal Flood WarningRIWWashakie12 hr
May 27, 1:46 AM MDTFlash Flood WatchRIWJohnson, Natrona25 hr
May 27, 9:40 AM MDTAreal Flood WarningRIWFremont47 hr
May 27, 10:24 AM MDTSpecial Weather StatementRIWFremont36 min
May 27, 11:03 AM MDTSpecial Weather StatementRIWFremont42 min
May 27, 11:19 AM MDTFlash Flood WarningRIWFremont3 hr
May 27, 11:42 AM MDTSpecial Weather StatementRIW33 min
May 27, 11:50 AM MDTSpecial Weather StatementRIW40 min
May 27, 11:58 AM MDTSpecial Weather StatementRIWFremont47 min
May 27, 12:01 PM MDTFlash Flood WarningRIWFremont3 hr
May 27, 12:15 PM MDTSpecial Weather StatementRIW45 min
May 27, 12:18 PM MDTTornado WarningRIWFremont27 min
May 27, 12:39 PM MDTSpecial Weather StatementRIW51 min
May 27, 12:45 PM MDTTornado WarningRIWFremont30 min
May 27, 12:52 PM MDTSevere Thunderstorm WarningRIWFremont38 min
May 27, 12:54 PM MDTFlash Flood WarningRIWSweetwater3 hr
May 27, 1:01 PM MDTFlash Flood WarningRIWFremont3 hr
May 27, 1:07 PM MDTSpecial Weather StatementRIWFremont38 min
May 27, 1:13 PM MDTSevere Thunderstorm WarningRIWFremont62 min
May 27, 1:25 PM MDTSpecial Weather StatementRIW50 min
May 27, 1:27 PM MDTSevere Thunderstorm WarningRIWSweetwater63 min
May 27, 1:38 PM MDTTornado WarningRIWSweetwater37 min
May 27, 2:03 PM MDTSpecial Weather StatementRIWFremont42 min
May 27, 2:12 PM MDTSpecial Weather StatementRIW33 min
May 27, 2:14 PM MDTSpecial Weather StatementRIWTeton46 min
May 27, 2:24 PM MDTSevere Thunderstorm WarningRIWNatrona51 min
May 27, 2:52 PM MDTSpecial Weather StatementRIWFremont38 min
May 27, 3:05 PM MDTSpecial Weather StatementRIW40 min
May 27, 3:13 PM MDTSpecial Weather StatementRIWNatrona47 min
May 27, 3:22 PM MDTSpecial Weather StatementRIWHot Springs53 min
May 27, 3:42 PM MDTSevere Thunderstorm WarningRIWNatrona48 min
May 27, 3:44 PM MDTSevere Thunderstorm WarningRIWNatrona46 min
May 27, 4:13 PM MDTTornado WarningRIWNatrona32 min
May 27, 4:18 PM MDTSpecial Weather StatementRIWHot Springs42 min
May 27, 4:29 PM MDTSevere Thunderstorm WarningRIWNatrona46 min
May 27, 4:38 PM MDTSevere Thunderstorm WarningRIWBig Horn, Hot Springs, Park, Washakie37 min
May 27, 4:46 PM MDTAreal Flood AdvisoryRIWNatrona119 min
May 27, 5:21 PM MDTSpecial Weather StatementRIWBig Horn39 min
May 27, 5:43 PM MDTSevere Thunderstorm WarningRIWBig Horn, Park47 min

Nearby

Tornado Warnings in Wyoming, 2018Every tornado warning in 2018Tornadoes in 2018

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.