Alert archive / Wyoming / Red Flag Warnings in 2021
Red Flag Warning 21, NWS Riverton, WY
NWS Riverton, WY issued this red flag warning at Sep 14, 2021, 1:14 PM MDT for 10 counties in Wyoming. It took effect at Sep 15, 2021, 11:00 AM MDT. It was in force for 33 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 14, 2021, 1:14 PM MDT (19:14 UTC)
- In effect from
- Sep 15, 2021, 11:00 AM MDT
- Expired
- Sep 16, 2021, 8:00 PM MDT
- In force
- 33 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 19:15 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, 7.2 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
- 5 J/kg
- Mixed-layer CIN
- -215 J/kg
- Mixed-layer LCL
- 1665 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 127 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
309 WWUS85 KRIW 141914 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 114 PM MDT Tue Sep 14 2021 WYZ277>279-151200- /O.UPG.KRIW.FW.A.0012.210915T1700Z-210916T0200Z/ /O.NEW.KRIW.FW.W.0021.210915T1700Z-210916T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 114 PM MDT Tue Sep 14 2021 ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM MDT WEDNESDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from 11 AM to 8 PM MDT Wednesday. the Fire Weather Watch is no longer in effect. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * 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 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 12 percent. * TEMPERATURES: Highs in the upper 70s to low 80s. 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. && $$ WYZ280-283-285-287>289-300-151200- /O.UPG.KRIW.FW.A.0012.210915T1700Z-210916T0200Z/ /O.NEW.KRIW.FW.W.0021.210915T1700Z-210916T0200Z/ Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin- South Bighorn Mountains-Owl Creek Mountains- East Wind River Mountains/South Shoshone NF- Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain- 114 PM MDT Tue Sep 14 2021 ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM MDT WEDNESDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from 11 AM to 8 PM MDT Wednesday. the Fire Weather Watch is no longer in effect. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...280...283...285...288...289...300. In North Central WY Fire Zone....287. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Washakie. In Southwest WY...Sweetwater. In West Central WY...Sublette. * WIND: West 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 9 percent. * TEMPERATURES: Highs from the upper 70s to mid 80s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ http://weather.gov/riverton
5 follow-up statements
583 WWUS85 KRIW 150813 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 213 AM MDT Wed Sep 15 2021 WYZ276-152015- /O.EXA.KRIW.FW.W.0021.210915T1700Z-210916T0200Z/ Cody Foothills- 213 AM MDT Wed Sep 15 2021 ...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from 11 AM this morning to 8 PM MDT this evening. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In North Central WY...Fire Weather Zone 276. * COUNTIES AFFECTED: In North Central WY...Park. * WIND: Southwest 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 13 percent. * TEMPERATURES: Highs around 80. 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. && $$ WYZ277>279-288-289-152015- /O.EXT.KRIW.FW.W.0021.210915T1700Z-210917T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- East Wind River Mountains/South Shoshone NF- Granite/Green/Ferris/Rattlesnake Mountains- 213 AM MDT Wed Sep 15 2021 ...RED FLAG WARNING NOW IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THURSDAY... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...288...289. In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: West 15 to 25 mph with gusts up to 40 mph. * HUMIDITY: As low as 11 percent. * TEMPERATURES: Highs in the mid 70s. Lows in the lower 40s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ280-283-285-287-300-152015- /O.CON.KRIW.FW.W.0021.210915T1700Z-210916T0200Z/ Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin- South Bighorn Mountains-Owl Creek Mountains-Casper Mountain- 213 AM MDT Wed Sep 15 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...280...283...285...300. In North Central WY Fire Zone....287. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Washakie. * WIND: West 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 9 percent. * TEMPERATURES: Highs in the upper 70s. 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. && $$ http://weather.gov/riverton
077 WWUS85 KRIW 151005 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 405 AM MDT Wed Sep 15 2021 WYZ277>279-288-289-160200- /O.CON.KRIW.FW.W.0021.210915T1700Z-210917T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- East Wind River Mountains/South Shoshone NF- Granite/Green/Ferris/Rattlesnake Mountains- 405 AM MDT Wed Sep 15 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THURSDAY... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...288...289. In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: West 15 to 25 mph with gusts up to 40 mph. * HUMIDITY: As low as 11 percent. * TEMPERATURES: Highs in the mid 70s. Lows in the lower 40s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ276-280-283-285-287-300-160200- /O.CON.KRIW.FW.W.0021.210915T1700Z-210916T0200Z/ Cody Foothills-Natrona County/Casper BLM- Upper Wind River Basin/Wind River Basin-South Bighorn Mountains- Owl Creek Mountains-Casper Mountain- 405 AM MDT Wed Sep 15 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...280...283...285...300. In North Central WY Fire Zones...276...287. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Park...Washakie. * WIND: West 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 9 percent. * TEMPERATURES: Highs in the upper 70s. 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. && $$ http://weather.gov/riverton
522 WWUS85 KRIW 160146 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 746 PM MDT Wed Sep 15 2021 WYZ276-280-283-285-287-300-160300- /O.EXP.KRIW.FW.W.0021.000000T0000Z-210916T0200Z/ Cody Foothills-Natrona County/Casper BLM- Upper Wind River Basin/Wind River Basin-South Bighorn Mountains- Owl Creek Mountains-Casper Mountain- 746 PM MDT Wed Sep 15 2021 ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING... Wind speeds will continue to decrease this evening and humidity will increase as well. As a result red flag conditions will no longer occur. Thus, the red flag warning will be allowed to expire at 8PM MDT. $$ WYZ277>279-288-289-161200- /O.CON.KRIW.FW.W.0021.000000T0000Z-210917T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- East Wind River Mountains/South Shoshone NF- Granite/Green/Ferris/Rattlesnake Mountains- 746 PM MDT Wed Sep 15 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THURSDAY... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Gusty Winds will create erratic fire behavior if new fires are initiated. * AFFECTED AREA: In Central WY Fire Zones...288...289. In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: West 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 10 percent. * TEMPERATURES: Lows in the mid 40s. Highs in the mid 70s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ http://weather.gov/riverton
139 WWUS85 KRIW 160834 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 234 AM MDT Thu Sep 16 2021 WYZ280-283-300-170200- /O.EXB.KRIW.FW.W.0021.210916T1800Z-210917T0200Z/ Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin- Casper Mountain- 234 AM MDT Thu Sep 16 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from noon today to 8 PM MDT this evening. * IMPACTS: Low Humidities and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY...Fire Weather Zones 280...283 and 300. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. * WIND: West 15 to 25 mph with gusts up to 30 mph. * HUMIDITY: As low as 12 percent. * TEMPERATURES: Highs from the mid 70s to the mid 80s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ277>279-288-289-170200- /O.CON.KRIW.FW.W.0021.000000T0000Z-210917T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- East Wind River Mountains/South Shoshone NF- Granite/Green/Ferris/Rattlesnake Mountains- 234 AM MDT Thu Sep 16 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING... * IMPACTS: Low Humidities and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...288...289. In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: Southwest 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 12 percent. * TEMPERATURES: Highs from the mid 70s to the lower 80s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ http://weather.gov/riverton
378 WWUS85 KRIW 161959 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 159 PM MDT Thu Sep 16 2021 WYZ277>279-288-289-171200- /O.NEW.KRIW.FW.W.0022.210917T1800Z-210918T0200Z/ /O.CON.KRIW.FW.W.0021.000000T0000Z-210917T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Upper Green River Basin/Rock Springs BLM- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- East Wind River Mountains/South Shoshone NF- Granite/Green/Ferris/Rattlesnake Mountains- 159 PM MDT Thu Sep 16 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING AND IS ALSO IN EFFECT FROM NOON TO 8 PM MDT FRIDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect until 8 PM MDT this evening, as well as from noon to 8 PM MDT Friday. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zones...288...289. In Southwest WY Fire Zones...277...279. In West Central WY Fire Zone....278. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln...Sublette. * WIND: West 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 10 percent. * TEMPERATURES: Highs in the mid to upper 70s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ280-300-171200- /O.NEW.KRIW.FW.W.0022.210917T1800Z-210918T0200Z/ /O.CON.KRIW.FW.W.0021.000000T0000Z-210917T0200Z/ Natrona County/Casper BLM-Casper Mountain- 159 PM MDT Thu Sep 16 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING AND IS ALSO IN EFFECT FROM NOON TO 8 PM MDT FRIDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect until 8 PM this evening, as well as from noon to 8 PM MDT Friday. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY...Fire Weather Zones 280 and 300. * COUNTIES AFFECTED: In Central WY...Natrona. * WIND: Northeast 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 11 percent. * TEMPERATURES: Highs from the upper 70s to low 80s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ281-285-286-414-416-171200- /O.NEW.KRIW.FW.W.0022.210917T1800Z-210918T0200Z/ Johnson County/Casper BLM-South Bighorn Mountains- Absaroka Mountains/North Shoshone NF- Salt and Wyoming Ranges/West Zone Bridger Teton NF- West Wind River Mountains/East Zone Bridger Teton NF- 159 PM MDT Thu Sep 16 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT FRIDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from noon to 8 PM MDT Friday. * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY Fire Zone....285. In North Central WY Fire Zone....281. In Northwest WY Fire Zone....286. In West Central WY Fire Zones...414...416. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In North Central WY...Hot Springs...Johnson...Park...Washakie. In West Central WY...Lincoln...Sublette. * WIND: Southwest 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 12 percent in the lower elevations, and 15 percent in the mountains. * TEMPERATURES: Highs in the low 80s in the lower elevations, and low 70s in the mountains. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ283-170200- /O.CON.KRIW.FW.W.0021.000000T0000Z-210917T0200Z/ Upper Wind River Basin/Wind River Basin- 159 PM MDT Thu Sep 16 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Central WY...Fire Weather Zone 283. * COUNTIES AFFECTED: In Central WY...Fremont. * WIND: Northwest 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 12 percent. * TEMPERATURES: Highs in the upper 70s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ 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 14, 1:36 AM MDT | Fire Weather Watch | RIW | Fremont, Hot Springs, Johnson, Lincoln, Natrona, Sublette and 3 more | 12 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.