Alert archive / Wyoming / Red Flag Warnings in 2021
Red Flag Warning 18, NWS Riverton, WY
NWS Riverton, WY issued this red flag warning at Sep 5, 2021, 1:49 PM MDT for 10 counties in Wyoming. It took effect at Sep 6, 2021, 12:00 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 5, 2021, 1:49 PM MDT (19:49 UTC)
- In effect from
- Sep 6, 2021, 12:00 PM MDT
- Expired
- Sep 6, 2021, 8:00 PM MDT
- In force
- 8 hr
- Issued by
- NWS Riverton, WY
Counties Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Lincoln County, WY, Natrona County, WY, Park County, WY, Sublette County, WY, Sweetwater County, WY, Uinta County, WY, Washakie County, WY
The radar
The Riverton/Lander radar (KRIW), 25 km from the middle of the area, began a volume at 19:48 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, 7.8 hours before the alert went out and 31 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 4439 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 50 m²/s²
- 0-3 km storm-relative helicity
- 64 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
337 WWUS85 KRIW 051949 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 149 PM MDT Sun Sep 5 2021 WYZ280-281-285-289-300-061300- /O.UPG.KRIW.FW.A.0009.210906T1800Z-210907T0200Z/ /O.NEW.KRIW.FW.W.0018.210906T1800Z-210907T0200Z/ Natrona County/Casper BLM-Johnson County/Casper BLM- South Bighorn Mountains-Granite/Green/Ferris/Rattlesnake Mountains- Casper Mountain- 149 PM MDT Sun Sep 5 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT MONDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from noon to 8 PM MDT Monday. The Fire Weather Watch is no longer in effect. * IMPACTS: Low humidity, unseasonably warm temperatures, and gusty wind will create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Central WY Fire Zones...280...285...289...300. In North Central WY Fire Zone....281. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Washakie. In Southwest WY...Sweetwater. * WIND: West-northwest 15 to 20 mph with gusts up to 30 mph. * HUMIDITY: As low as 7 percent. * TEMPERATURES: Highs in the mid to upper 80s in the lower elevations, and around 80 in the mountains. 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. && $$ WYZ276-283-287-061300- /O.EXA.KRIW.FW.A.0009.210906T1800Z-210907T0200Z/ Cody Foothills-Upper Wind River Basin/Wind River Basin- Owl Creek Mountains- 149 PM MDT Sun Sep 5 2021 ...FIRE WEATHER WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH MONDAY EVENING... The National Weather Service in Riverton has issued a Fire Weather Watch, which is in effect from Monday afternoon through Monday evening. * IMPACTS: Low humidity, unseasonably warm temperatures, and gusty wind could create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Central WY Fire Zone....283. In North Central WY Fire Zones...276...287. * COUNTIES AFFECTED: In Central WY...Fremont. In North Central WY...Hot Springs...Park. * WIND: West-northwest 10 to 20 mph with gusts 25 to 30 mph. * HUMIDITY: As low as 7 percent. * TEMPERATURES: Highs 85 to 90, and around 80 in the mountains. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$ WYZ277>279-061300- /O.CON.KRIW.FW.A.0009.210906T1800Z-210907T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 149 PM MDT Sun Sep 5 2021 ...FIRE WEATHER WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON THROUGH MONDAY EVENING... * IMPACTS: Low humidity, unseasonably warm temperatures, and gusty wind could create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: West-northwest 10 to 20 mph with gusts 25 to 30 mph. * HUMIDITY: As low as 7 percent. * TEMPERATURES: Highs 80 to 85. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$ http://weather.gov/riverton
2 follow-up statements
841 WWUS85 KRIW 060832 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 232 AM MDT Mon Sep 6 2021 WYZ276-283-287-070200- /O.UPG.KRIW.FW.A.0009.210906T1800Z-210907T0200Z/ /O.EXA.KRIW.FW.W.0018.210906T1800Z-210907T0200Z/ Cody Foothills-Upper Wind River Basin/Wind River Basin- Owl Creek Mountains- 232 AM MDT Mon Sep 6 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from Noon today to 8 PM MDT this evening. The Fire Weather Watch is no longer in effect. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Gusty Winds will create erratic fire behavior if any new fires start. * AFFECTED AREA: In Central WY Fire Zone....283. In North Central WY Fire Zones...276...287. * COUNTIES AFFECTED: In Central WY...Fremont. In North Central WY...Hot Springs...Park. * WIND: West to Northwest 15 to 20 mph with gusts 25 to around 30 mph. * HUMIDITY: As low as 7 percent. * TEMPERATURES: Highs in the 80s to around 90. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected to occur during the warning times. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ277>279-070200- /O.UPG.KRIW.FW.A.0009.210906T1800Z-210907T0200Z/ /O.EXA.KRIW.FW.W.0018.210906T1800Z-210907T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 232 AM MDT Mon Sep 6 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from Noon today to 8 PM MDT this evening. The Fire Weather Watch is no longer in effect. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Gusty Winds will create erratic fire behavior if any new fires were to start. * AFFECTED AREA: In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: West 15 to 20 mph with gusts 25 to 30 mph. * HUMIDITY: As low as 7 percent. * TEMPERATURES: Highs in the lower to mid 80s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected to occur during the warning times. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ286-070200- /O.EXA.KRIW.FW.W.0018.210906T1800Z-210907T0200Z/ Absaroka Mountains/North Shoshone NF- 232 AM MDT Mon Sep 6 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from Noon today to 8 PM MDT this evening. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Gusty Winds will create erratic fire behavior if any new fires were to start. * AFFECTED AREA: In Northwest WY...Fire Weather Zone 286. * COUNTIES AFFECTED: In Central WY...Fremont. In North Central WY...Hot Springs...Park. * WIND: West 15 to 25 mph with gusts 30 to 35 mph. * HUMIDITY: As low as 8 percent. * TEMPERATURES: Highs in the 70s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected to occur during the warning times. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ280-281-285-289-300-070200- /O.CON.KRIW.FW.W.0018.210906T1800Z-210907T0200Z/ Natrona County/Casper BLM-Johnson County/Casper BLM- South Bighorn Mountains-Granite/Green/Ferris/Rattlesnake Mountains- Casper Mountain- 232 AM MDT Mon Sep 6 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Gusty Winds will create erratic fire behavior if any new fires were to start. * AFFECTED AREA: In Central WY Fire Zones...280...285...289...300. In North Central WY Fire Zone....281. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Washakie. In Southwest WY...Sweetwater. * WIND: Northwest 15 to 25 mph with gusts around 30 mph. * HUMIDITY: As low as 7 percent. * TEMPERATURES: Highs in the 80s at lower elevations. Highs in the 70s in the mountains. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected to occur during the warning times. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ http://weather.gov/riverton
293 WWUS85 KRIW 070136 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 736 PM MDT Mon Sep 6 2021 WYZ280-281-285-289-300-070245- /O.EXP.KRIW.FW.W.0018.000000T0000Z-210907T0200Z/ Natrona County/Casper BLM-Johnson County/Casper BLM- South Bighorn Mountains-Granite/Green/Ferris/Rattlesnake Mountains- Casper Mountain- 736 PM MDT Mon Sep 6 2021 ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING... Winds have decreased and will continue to weaken throughout the early overnight hours, reducing the fire danger. $$ WYZ276-283-286-287-070245- /O.EXP.KRIW.FW.W.0018.000000T0000Z-210907T0200Z/ Cody Foothills-Upper Wind River Basin/Wind River Basin- Absaroka Mountains/North Shoshone NF-Owl Creek Mountains- 736 PM MDT Mon Sep 6 2021 ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING... Winds have decreased and will continue to weaken throughout the early overnight hours, reducing the fire danger. $$ WYZ277>279-070245- /O.EXP.KRIW.FW.W.0018.000000T0000Z-210907T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 736 PM MDT Mon Sep 6 2021 ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING... Winds have decreased and will continue to weaken throughout the early overnight hours, reducing the fire danger. $$ http://weather.gov/riverton
The office that day
Everything else NWS Riverton, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 2:13 AM MDT | Fire Weather Watch | RIW | Fremont, Hot Springs, Johnson, Lincoln, Natrona, Park and 4 more | 24 hr |
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.