Alert archive / Wyoming / Red Flag Warnings in 2021
Red Flag Warning 23, NWS Riverton, WY
NWS Riverton, WY issued this red flag warning at Sep 21, 2021, 1:37 PM MDT for 5 counties in Wyoming. It took effect at Sep 22, 2021, 12:00 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
- Sep 21, 2021, 1:37 PM MDT (19:37 UTC)
- In effect from
- Sep 22, 2021, 12:00 PM MDT
- Expired
- Sep 22, 2021, 7:11 PM MDT
- In force
- 7 hr
- Issued by
- NWS Riverton, WY
Counties Fremont County, WY, Lincoln County, WY, Natrona County, WY, Sweetwater County, WY, Uinta County, WY
The radar
The Riverton/Lander radar (KRIW), 105 km from the middle of the area, began a volume at 19:40 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, 7.6 hours before the alert went out and 108 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
- 1877 m above ground
- 0-6 km bulk shear
- 72 kt
- 0-1 km storm-relative helicity
- 59 m²/s²
- 0-3 km storm-relative helicity
- 161 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
330 WWUS85 KRIW 211937 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 137 PM MDT Tue Sep 21 2021 WYZ277-279-230200- /O.UPG.KRIW.FW.A.0013.210922T1800Z-210923T0200Z/ /O.NEW.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 137 PM MDT Tue Sep 21 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT WEDNESDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from noon to 8 PM MDT Wednesday. the Fire Weather Watch is no longer in effect.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 Southwest WY...Fire Weather Zones 277 and 279. * COUNTIES AFFECTED: In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln. * WIND: West 15 to 20 mph with gusts 25 to 30 mph. * HUMIDITY: 11 to 14 percent. * TEMPERATURES: Highs 70 to 75. 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. && $$ WYZ280-289-230200- /O.UPG.KRIW.FW.A.0013.210922T1800Z-210923T0200Z/ /O.NEW.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Natrona County/Casper BLM- Granite/Green/Ferris/Rattlesnake Mountains- 137 PM MDT Tue Sep 21 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT WEDNESDAY... The National Weather Service in Riverton has issued a Red Flag Warning, which is in effect from noon to 8 PM MDT Wednesday. the Fire Weather Watch is no longer in effect. * IMPACTS: Low humidity, unseasonably warm temperatures, and gusty wind will create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Central WY...Fire Weather Zones 280 and 289. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater. * WIND: Southwest 15 to 20 mph with gusts around 30 mph. * HUMIDITY: 11 to 14 percent. * TEMPERATURES: Highs 75 to 80. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ http://weather.gov/riverton
3 follow-up statements
839 WWUS85 KRIW 220712 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 112 AM MDT Wed Sep 22 2021 WYZ300-222200- /O.EXA.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Casper Mountain- 112 AM MDT Wed Sep 22 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 humidity, unseasonably warm temperatures, and gusty wind will create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Central WY...Fire Weather Zone 300. * COUNTIES AFFECTED: In Central WY...Natrona. * WIND: Southwest 10 to 20 mph with gusts between 25 and 30 mph. * HUMIDITY: As low as 13 percent. * TEMPERATURES: Highs in the upper 60s. 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. && $$ WYZ277-279-222200- /O.CON.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 112 AM MDT Wed Sep 22 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... * IMPACTS: Low humidity, unseasonably warm temperatures, and gusty wind will create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Southwest WY...Fire Weather Zones 277 and 279. * COUNTIES AFFECTED: In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln. * WIND: West 10 to 20 mph with gusts up to 30 mph. * HUMIDITY: As low as 11 percent. * TEMPERATURES: Highs in the lower 70s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ280-289-222200- /O.CON.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Natrona County/Casper BLM- Granite/Green/Ferris/Rattlesnake Mountains- 112 AM MDT Wed Sep 22 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING... * IMPACTS: Low humidity, unseasonably warm temperatures, and gusty wind will create erratic fire behavior and rapid fire spread. * AFFECTED AREA: In Central WY...Fire Weather Zones 280 and 289. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater. * WIND: Southwest 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 11 percent. * TEMPERATURES: Highs in the 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. && $$ Team Riverton/21
678 WWUS85 KRIW 221758 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 1158 AM MDT Wed Sep 22 2021 WYZ277-279-230200- /O.CON.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- 1158 AM MDT Wed Sep 22 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING... * IMPACTS: Low Humidities...Unseasonably Warm Temperatures...and Strong Gusty Winds will create erratic fire behavior and new fire starts. * AFFECTED AREA: In Southwest WY...Fire Weather Zones 277 and 279. * COUNTIES AFFECTED: In Southwest WY...Sweetwater...Uinta. In West Central WY...Lincoln. * WIND: West 10 to 20 mph with gusts up to 30 mph. * HUMIDITY: As low as 10 percent. * TEMPERATURES: Highs in the low to mid 70s. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ WYZ280-289-300-230200- /O.CON.KRIW.FW.W.0023.210922T1800Z-210923T0200Z/ Natrona County/Casper BLM- Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain- 1158 AM MDT Wed Sep 22 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 Zones 280...289...and 300. * COUNTIES AFFECTED: In Central WY...Fremont...Natrona. In Southwest WY...Sweetwater. * WIND: Southwest 15 to 25 mph with gusts up to 35 mph. * HUMIDITY: As low as 10 percent. * TEMPERATURES: Highs in the 70s in the lower elevations, and highs in the upper 60s in the higher elevation. 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. && $$ http://weather.gov/riverton
822 WWUS85 KRIW 230111 RFWRIW URGENT - FIRE WEATHER MESSAGE National Weather Service Riverton WY 711 PM MDT Wed Sep 22 2021 WYZ277-279-280-289-300-230215- /O.CAN.KRIW.FW.W.0023.000000T0000Z-210923T0200Z/ Lincoln and Uinta Counties/Lower Elevations- Sweetwater County/Rock Springs BLM/Flaming Gorge NRA- Natrona County/Casper BLM- Granite/Green/Ferris/Rattlesnake Mountains-Casper Mountain- 711 PM MDT Wed Sep 22 2021 ...RED FLAG WARNING IS CANCELLED... The National Weather Service in Riverton has cancelled the Red Flag Warning. Winds have begun to decrease below critical thresholds and relative humidities will continue to rise after sunset. $$ 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 21, 2:12 AM MDT | Fire Weather Watch | RIW | Fremont, Lincoln, Natrona, Sweetwater, Uinta | 11 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.