Alert archive / Wyoming / Red Flag Warnings in 2017

Red Flag Warning 2, NWS Riverton, WY

September 2, 20177 counties in Wyoming

NWS Riverton, WY issued this red flag warning at Sep 2, 2017, 8:20 PM MDT for 7 counties in Wyoming. It took effect at Sep 3, 2017, 1:16 PM MDT. It was in force for 8 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
Sep 2, 2017, 8:20 PM MDT (02:20 UTC)
In effect from
Sep 3, 2017, 1:16 PM MDT
Expired
Sep 3, 2017, 9:00 PM MDT
In force
8 hr
Issued by
NWS Riverton, WY

Counties Fremont County, WY, Johnson County, WY, Lincoln County, WY, Natrona County, WY, Sublette County, WY, Sweetwater County, WY, Uinta County, WY

The radar

The Riverton/Lander radar (KRIW), 63 km from the middle of the area, began a volume at 02:21 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, 2.3 hours before the alert went out and 67 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 2017-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 joules per kilogram.LCLLFCEL10008507005003002001001 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 2017-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939Sfc1 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
7 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
3714 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

489 
WWUS85 KRIW 030220
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
820 PM MDT Sat Sep 2 2017

WYZ277>279-414-030800-
/O.UPG.KRIW.FW.A.0001.170903T2000Z-170904T0300Z/
/O.NEW.KRIW.FW.W.0002.170903T2000Z-170904T0300Z/
Lincoln and Uinta Counties/Lower Elevations-
Upper Green River Basin/Rock Springs BLM-
Sweetwater County/Rock Springs BLM/Flaming Gorge NRA-
Salt and Wyoming Ranges/West Zone Bridger Teton NF-
820 PM MDT Sat Sep 2 2017

...RED FLAG WARNING IN EFFECT FROM 2 PM TO 9 PM MDT SUNDAY...

The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect from 2 PM to 9 PM MDT Sunday. the Fire
Weather Watch is no longer in effect.

* IMPACTS: Low Humidities, Hot Temperatures, and Extreme
  Instability will create erratic fire behavior. 

* AFFECTED AREA: 
  In Southwest WY Fire Zones...277...279.
  In West Central WY Fire Zones...278...414.

* COUNTIES AFFECTED: 
  In Southwest WY...Sweetwater...Uinta.
  In West Central WY...Lincoln...Sublette.

* HUMIDITY: As low as 9 percent.

* TEMPERATURES: In the lower to mid 80s in the mountains...mid 80s
  to lower 90s across the lower elevations.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions will 
occur. A combination of low relative humidity...very warm 
temperatures...and extreme instability will contribute to extreme 
fire behavior.

&&

$$

WYZ280-283-289-300-030800-
/O.UPG.KRIW.FW.A.0001.170903T2000Z-170904T0300Z/
/O.NEW.KRIW.FW.W.0002.170903T2000Z-170904T0300Z/
Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin-
Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain-
820 PM MDT Sat Sep 2 2017

...RED FLAG WARNING IN EFFECT FROM 2 PM TO 9 PM MDT SUNDAY...

The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect from 2 PM to 9 PM MDT Sunday. the Fire
Weather Watch is no longer in effect.

* IMPACTS: Low Humidities, Hot Temperatures, and Extreme
  Instability will create erratic fire behavior. 

* AFFECTED AREA: 
  In Central WY...Fire Weather Zones 280...283...289 and 300.

* COUNTIES AFFECTED: 
  In Central WY...Fremont...Natrona.
  In Southwest WY...Sweetwater.

* HUMIDITY: As low as 6 percent.

* TEMPERATURES: In the lower to mid 80s in the mountains...upper
  80s to upper 90s across the lower elevations.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions will 
occur. A combination of low relative humidity...very warm 
temperatures...and extreme instability will contribute to extreme 
fire behavior.

&&

$$

http://weather.gov/riverton
3 follow-up statements
011 
WWUS85 KRIW 030604
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
1204 AM MDT Sun Sep 3 2017

WYZ277>279-414-032200-
/O.CON.KRIW.FW.W.0002.170903T2000Z-170904T0300Z/
Lincoln and Uinta Counties/Lower Elevations-
Upper Green River Basin/Rock Springs BLM-
Sweetwater County/Rock Springs BLM/Flaming Gorge NRA-
Salt and Wyoming Ranges/West Zone Bridger Teton NF-
1204 AM MDT Sun Sep 3 2017

...RED FLAG WARNING REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO
9 PM MDT THIS EVENING...

* IMPACTS: Low Humidities, Hot Temperatures, and Extreme
  Instability will create erratic fire behavior. 

* AFFECTED AREA: 
  In Southwest WY Fire Zones...277...279.
  In West Central WY Fire Zones...278...414.

* COUNTIES AFFECTED: 
  In Southwest WY...Sweetwater...Uinta.
  In West Central WY...Lincoln...Sublette.

* HUMIDITY: As low as 9 percent.

* TEMPERATURES: In the lower to mid 80s in the mountains...mid 
  80s to lower 90s across the lower elevations.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
will occur. A combination of low relative humidity...very warm
temperatures...and extreme instability will contribute to extreme
fire behavior.

&&

$$

WYZ280-283-289-300-032200-
/O.CON.KRIW.FW.W.0002.170903T2000Z-170904T0300Z/
Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin-
Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain-
1204 AM MDT Sun Sep 3 2017

...RED FLAG WARNING REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO
9 PM MDT THIS EVENING...

* IMPACTS: Low Humidities, Hot Temperatures, and Extreme
  Instability will create erratic fire behavior. 

* AFFECTED AREA: 
  In Central WY...Fire Weather Zones 280...283...289 and 300.

* COUNTIES AFFECTED: 
  In Central WY...Fremont...Natrona.
  In Southwest WY...Sweetwater.

* HUMIDITY: As low as 6 percent.

* TEMPERATURES: In the lower to mid 80s in the mountains...upper 
  80s to upper 90s across the lower elevations.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
will occur. A combination of low relative humidity...very warm
temperatures...and extreme instability will contribute to extreme
fire behavior.

&&

$$

http://weather.gov/riverton
194 
WWUS85 KRIW 031916
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
116 PM MDT Sun Sep 3 2017

WYZ281-040300-
/O.EXB.KRIW.FW.W.0002.170903T1916Z-170904T0300Z/
Johnson County/Casper BLM-
116 PM MDT Sun Sep 3 2017

...RED FLAG WARNING IN EFFECT UNTIL 9 PM MDT THIS EVENING...

The National Weather Service in Riverton has issued a Red Flag
Warning, which is in effect until 9 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 North Central WY...Fire Weather Zone 281.

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

* HUMIDITY: as low as 11 percent.

* TEMPERATURES: In the mid 80s.

* WIND: North 15 to 20 mph with gusts up to 30 mph.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Outdoor burning is not recommended.  Fires may spread rapidly.

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.

&&

$$

WYZ277>279-414-040300-
/O.EXT.KRIW.FW.W.0002.170903T1916Z-170904T0300Z/
Lincoln and Uinta Counties/Lower Elevations-
Upper Green River Basin/Rock Springs BLM-
Sweetwater County/Rock Springs BLM/Flaming Gorge NRA-
Salt and Wyoming Ranges/West Zone Bridger Teton NF-
116 PM MDT Sun Sep 3 2017

...RED FLAG WARNING NOW IN EFFECT UNTIL 9 PM MDT THIS EVENING...

* IMPACTS: Low Humidities...Hot Temperatures...Gusty Winds and a
  very unstable air mass, haines index 6, will create erratic fire
  behavior and new fire starts. 

* AFFECTED AREA: 
  In Southwest WY Fire Zones...277...279.
  In West Central WY Fire Zones...278...414.

* COUNTIES AFFECTED: 
  In Southwest WY...Sweetwater...Uinta.
  In West Central WY...Lincoln...Sublette.

* HUMIDITY: as low as 9 percent.

* TEMPERATURES: In the upper 70s to mid 80s.

* HAINES INDEX: 6.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Outdoor burning is not recommended.  Fires may spread rapidly.

A Red Flag Warning means that critical fire weather conditions
will occur. A combination of low relative humidity...very warm
temperatures...and extreme instability will contribute to extreme
fire behavior.

&&

$$

WYZ280-283-289-300-040300-
/O.EXT.KRIW.FW.W.0002.170903T1916Z-170904T0300Z/
Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin-
Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain-
116 PM MDT Sun Sep 3 2017

...RED FLAG WARNING NOW IN EFFECT UNTIL 9 PM MDT THIS EVENING...

* IMPACTS: Low Humidities...Hot Temperatures...Gusty Winds and a
  very unstable air mass, Haines Index 6, will create erratic fire
  behavior and new fire starts. 

* AFFECTED AREA: 
  In Central WY...Fire Weather Zones 280...283...289 and 300.

* COUNTIES AFFECTED: 
  In Central WY...Fremont...Natrona.
  In Southwest WY...Sweetwater.

* HUMIDITY: as low as 10 percent.

* TEMPERATURES: In the mid 80s to mid 90s.

* HAINES INDEX: 6.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Outdoor burning is not recommended.  Fires may spread rapidly.

A Red Flag Warning means that critical fire weather conditions
will occur. A combination of low relative humidity...very warm
temperatures...and extreme instability will contribute to extreme
fire behavior.

&&

$$

http://weather.gov/riverton
113 
WWUS85 KRIW 040308
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
908 PM MDT Sun Sep 3 2017

WYZ277>281-283-289-300-414-040415-
/O.EXP.KRIW.FW.W.0002.000000T0000Z-170904T0300Z/
Lincoln and Uinta Counties/Lower Elevations-
Upper Green River Basin/Rock Springs BLM-
Sweetwater County/Rock Springs BLM/Flaming Gorge NRA-
Natrona County/Casper BLM-Johnson County/Casper BLM-
Upper Wind River Basin/Wind River Basin-
Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain-
Salt and Wyoming Ranges/West Zone Bridger Teton NF-
908 PM MDT Sun Sep 3 2017

...RED FLAG WARNING HAS EXPIRED...

Red Flag conditions have ended over the area and thus the Red Flag
Warning has been allowed to expire as of 900 PM MDT this evening.

$$

http://weather.gov/riverton

Nearby

Red Flag Warnings in Wyoming, 2017Every red flag warning in 2017

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.