Alert archive / Wyoming / Red Flag Warnings in 2021

Red Flag Warning 1, NWS Riverton, WY

June 15, 20215 counties in Wyoming

NWS Riverton, WY issued this red flag warning at Jun 15, 2021, 3:13 AM MDT for 5 counties in Wyoming. It took effect at Jun 15, 2021, 1:00 PM MDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 15, 2021, 3:13 AM MDT (09:13 UTC)
In effect from
Jun 15, 2021, 1:00 PM MDT
Expired
Jun 15, 2021, 8:00 PM MDT
In force
7 hr
Issued by
NWS Riverton, WY

Counties Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Natrona County, WY, Washakie County, WY

The radar

The Riverton/Lander radar (KRIW), 86 km from the middle of the area, began a volume at 09:12 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, 9.2 hours before the alert went out and 81 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 2021-06-15Temperature 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 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 2021-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
4874 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

342 
WWUS85 KRIW 150913
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
313 AM MDT Tue Jun 15 2021

WYZ280-281-300-152115-
/O.NEW.KRIW.FW.W.0001.210615T1900Z-210616T0200Z/
Natrona County/Casper BLM-Johnson County/Casper BLM-
Casper Mountain-
313 AM MDT Tue Jun 15 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 8 PM MDT
THIS EVENING...

The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect from 1 PM this afternoon to 8 PM MDT
this evening.

* IMPACTS: Low Humidities...Hot Temperatures...and Strong Gusty 
  Winds will create erratic fire behavior and new fire starts. 

* AFFECTED AREA: 
  In Central WY Fire Zones...280...300.
  In North Central WY Fire Zone....281.

* COUNTIES AFFECTED: 
  In Central WY...Natrona.
  In North Central WY...Johnson.

* WIND: Southwest 15 to 20 mph with gusts up to 35 mph.

* HUMIDITY: As low as 5 percent.

* TEMPERATURES: Highs in the upper 90s to mid 100s across lower
  elevations and low 90s across Casper Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

WYZ285-152115-
/O.NEW.KRIW.FW.W.0001.210615T1900Z-210616T0200Z/
South Bighorn Mountains-
313 AM MDT Tue Jun 15 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 8 PM MDT
THIS EVENING...

The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect from 1 PM this afternoon to 8 PM MDT
this evening.

* IMPACTS: Low Humidities...Hot Temperatures...and Strong Gusty 
  Winds will create erratic fire behavior and new fire starts. 

* AFFECTED AREA: 
  In Central WY...Fire Weather Zone 285.

* COUNTIES AFFECTED: 
  In Central WY...Fremont...Natrona.
  In North Central WY...Hot Springs...Johnson...Washakie.

* WIND: Southwest 15 to 25 mph with gusts up to 40 mph.

* HUMIDITY: As low as 6 percent.

* TEMPERATURES: Highs in the upper 80s to mid 90s.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

http://weather.gov/riverton
2 follow-up statements
358 
WWUS85 KRIW 151812
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
1212 PM MDT Tue Jun 15 2021

WYZ280-281-300-160200-
/O.CON.KRIW.FW.W.0001.210615T1900Z-210616T0200Z/
Natrona County/Casper BLM-Johnson County/Casper BLM-
Casper Mountain-
1212 PM MDT Tue Jun 15 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS
EVENING...

* IMPACTS: Low Humidities...Hot Temperatures...and Strong Gusty 
  Winds will create erratic fire behavior and new fire starts. 

* AFFECTED AREA: 
  In Central WY Fire Zones...280...300.
  In North Central WY Fire Zone....281.

* COUNTIES AFFECTED: 
  In Central WY...Natrona.
  In North Central WY...Johnson.

* WIND: Southwest 15 to 20 mph with gusts up to 35 mph.

* HUMIDITY: As low as 5 percent.

* TEMPERATURES: Highs in the upper 90s to 105 across lower 
  elevations and low 90s across Casper Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

WYZ285-160200-
/O.CON.KRIW.FW.W.0001.210615T1900Z-210616T0200Z/
South Bighorn Mountains-
1212 PM MDT Tue Jun 15 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS
EVENING...

* IMPACTS: Low Humidities...Hot Temperatures...and Strong Gusty 
  Winds will create erratic fire behavior and new fire starts. 

* AFFECTED AREA: 
  In Central WY...Fire Weather Zone 285.

* COUNTIES AFFECTED: 
  In Central WY...Fremont...Natrona.
  In North Central WY...Hot Springs...Johnson...Washakie.

* WIND: Southwest 15 to 25 mph with gusts up to 40 mph.

* HUMIDITY: As low as 6 percent.

* TEMPERATURES: Highs in the upper 80s to mid 90s.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

http://weather.gov/riverton
327 
WWUS85 KRIW 160148
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
748 PM MDT Tue Jun 15 2021

WYZ280-281-300-160300-
/O.EXP.KRIW.FW.W.0001.000000T0000Z-210616T0200Z/
Natrona County/Casper BLM-Johnson County/Casper BLM-
Casper Mountain-
748 PM MDT Tue Jun 15 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING...

Wind speeds will continue to decrease this evening along with
cooling temperatures. Thus, Red Flag conditions will be ending
after 8 PM MDT. The Red Flag Warning will be allowed to expire.

$$

WYZ285-160300-
/O.EXP.KRIW.FW.W.0001.000000T0000Z-210616T0200Z/
South Bighorn Mountains-
748 PM MDT Tue Jun 15 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING...

Wind speeds will continue to decrease this evening along with
cooling temperatures. Thus, Red Flag conditions will be ending
after 8 PM MDT. The Red Flag Warning will be allowed to expire.

$$

http://weather.gov/riverton

Nearby

Red Flag Warnings in Wyoming, 2021Every red flag 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.