Alert archive / Wyoming / Flash Flood Warnings in 2021

Flash Flood Warning 4, NWS Riverton, WY

July 31, 2021Lincoln County, Wyoming

NWS Riverton, WY issued this flash flood warning at Jul 31, 2021, 4:10 PM MDT for Lincoln County, Wyoming. It was in force for 4 hr. 1 report 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: Jul 31, 2021, 4:10 PM MDT (22:10 UTC)
Expired: Jul 31, 2021, 8:15 PM MDT
In force: 4 hr
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Flood severity: None

County Lincoln County, WY

The radar

The Salt Lake City radar (KMTX), 153 km from the middle of the area, began a volume at 22:13 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	Remark
Jul 31, 5:25 PM MDT	FLASH FLOOD	Kemmerer, WY	QUITE A FEW FLOODED BASEMENTS IN KEMMERER AND DIAMONDVILLE.

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

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 10.2 hours before the alert went out and 158 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: 149 J/kg
Mixed-layer CIN: -128 J/kg
Mixed-layer LCL: 1716 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

004 
WGUS55 KRIW 312210
FFWRIW
WYC023-010215-
/O.NEW.KRIW.FF.W.0004.210731T2210Z-210801T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Riverton WY
410 PM MDT Sat Jul 31 2021

The National Weather Service in Riverton has issued a

* Flash Flood Warning for...
  Southwestern Lincoln County in west central Wyoming...

* Until 815 PM MDT.

* At 410 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.75 and 1 inch of rain 
  has fallen. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets as well as other drainage and low
           lying areas. Rural roads could become washed out. Also
           some mud slides could occur in steep terrain.

* Some locations that will experience flash flooding include...
  Kemmerer, Cokeville, Diamondville, Fossil Butte National Monument, 
  Sage Junction, Lake Viva Naughton, Elkol, Cokeville Municipal 
  Airport and Kemmerer Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4231 11103 4229 11076 4196 11044 4168 11038
      4173 11104 4179 11105 4183 11105 4184 11105

FLASH FLOOD...RADAR INDICATED

$$

Murrell

3 follow-up statements

894 
WGUS75 KRIW 312347
FFSRIW

Flash Flood Statement
National Weather Service Riverton WY
547 PM MDT Sat Jul 31 2021

WYC023-010215-
/O.CON.KRIW.FF.W.0004.000000T0000Z-210801T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln WY-
547 PM MDT Sat Jul 31 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM MDT THIS 
EVENING FOR SOUTHWESTERN LINCOLN COUNTY...

At 547 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across southern Lincoln County. The heaviest rain was occurring 
between Sage and Cokeville. Between 0.75 and 1.25 inches of rain 
with isolated higher amounts have fallen in most locations. Flash 
flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flooding of small creeks and streams, urban areas,
         highways, streets as well as other drainage and low
         lying areas.

Some locations that could experience flash flooding include...
  Kemmerer, Cokeville, Diamondville, Fossil Butte National Monument, 
  Sage Junction, Lake Viva Naughton, and Elkol,

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 4231 11103 4229 11076 4196 11044 4168 11038
      4173 11104 4179 11105 4183 11105 4184 11105

FLASH FLOOD...RADAR INDICATED

$$

Murrell

800 
WGUS75 KRIW 010136
FFSRIW

Flash Flood Statement
National Weather Service Riverton WY
736 PM MDT Sat Jul 31 2021

WYC023-010215-
/O.CON.KRIW.FF.W.0004.000000T0000Z-210801T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln WY-
736 PM MDT Sat Jul 31 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM MDT THIS 
EVENING FOR SOUTHWESTERN LINCOLN COUNTY...

At 736 PM MDT, Doppler radar currently shows moderate rain 
continuing around the Cokeville area where there is still a threat 
for some flash flooding. The southern part of the flash flood 
warning for Kemmerer and Diamondville has been cancelled.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flooding of small creeks and streams, urban areas,
         highways, streets as well as other drainage and low
         lying areas.

Some locations that will experience flash flooding include...
  Cokeville, and Lake Viva Naughton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 4190 11105 4192 11105 4231 11103 4229 11076
      4196 11044 4194 11054

FLASH FLOOD...RADAR INDICATED

$$

Murrell

250 
WGUS75 KRIW 010206
FFSRIW

Flash Flood Statement
National Weather Service Riverton WY
806 PM MDT Sat Jul 31 2021

WYC023-010216-
/O.EXP.KRIW.FF.W.0004.000000T0000Z-210801T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln WY-
806 PM MDT Sat Jul 31 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 815 PM MDT THIS EVENING FOR 
SOUTHWESTERN LINCOLN COUNTY...

Flood waters have receded. Flooding is no longer expected to pose a 
threat.



LAT...LON 4190 11105 4192 11105 4231 11103 4229 11076
      4196 11044 4194 11054

$$

Murrell

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 6:18 PM MDT	Flash Flood Warning	RIW	Sweetwater	3 hr
Jul 30, 6:31 PM MDT	Areal Flood Advisory	RIW	Natrona	119 min
Jul 30, 7:18 PM MDT	Special Weather Statement	RIW		27 min
Jul 30, 7:56 PM MDT	Special Weather Statement	RIW		34 min
Jul 30, 8:25 PM MDT	Flash Flood Warning	RIW	Fremont, Natrona	3 hr
Jul 30, 8:34 PM MDT	Special Weather Statement	RIW		26 min
Jul 30, 8:45 PM MDT	Special Weather Statement	RIW	Johnson	30 min
Jul 30, 9:45 PM MDT	Special Weather Statement	RIW	Fremont	30 min
Jul 31, 1:41 PM MDT	Areal Flood Advisory	RIW	Big Horn	3 hr
Jul 31, 3:26 PM MDT	Special Weather Statement	RIW	Lincoln	34 min
Jul 31, 3:31 PM MDT	Special Weather Statement	RIW		29 min
Jul 31, 3:48 PM MDT	Areal Flood Advisory	RIW	Lincoln	36 min
Jul 31, 3:58 PM MDT	Special Weather Statement	RIW	Fremont	32 min
Jul 31, 4:21 PM MDT	Special Weather Statement	RIW	Lincoln	24 min
Jul 31, 4:45 PM MDT	Areal Flood Advisory	RIW	Fremont	60 min
Jul 31, 5:03 PM MDT	Special Weather Statement	RIW	Teton	42 min

Nearby

Flash Flood Warnings in Wyoming, 2021 Every flash flood 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.