Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 26, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Dec 20, 2021, 1:08 PM MST for 8 counties in Colorado. It took effect at Dec 21, 2021, 9:00 AM MST. 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
- Dec 20, 2021, 1:08 PM MST (20:08 UTC)
- In effect from
- Dec 21, 2021, 9:00 AM MST
- Expired
- Dec 21, 2021, 5:00 PM MST
- In force
- 8 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Boulder County, CO, Clear Creek County, CO, Douglas County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Park County, CO, Weld County, CO
The radar
The Denver radar (KFTG), 64 km from the middle of the area, began a volume at 20:07 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
Denver, CO (KDNR), launched 12:00Z, 8.1 hours before the alert went out and 175 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
- 3587 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
318 WWUS85 KBOU 202008 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 108 PM MST Mon Dec 20 2021 ...CRITICAL FIRE WEATHER CONDITIONS TUESDAY AFTERNOON... .Very dry and locally breezy conditions will result several hours of critical fire weather conditions Tuesday afternoon for the Cheyenne Ridge, lower elevation foothills, and portions of the Palmer Divide. COZ215-216-238-242-210415- /O.NEW.KBOU.FW.W.0026.211221T1600Z-211222T0000Z/ Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Larimer County Below 6000 Feet/Northwest Weld County- Northeast Weld County- 108 PM MST Mon Dec 20 2021 ...RED FLAG WARNING IN EFFECT FROM 9 AM TO 5 PM MST TUESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR CHEYENNE RIDGE, FOOTHILLS AND PORTIONS OF PALMER DIVIDE... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 9 AM to 5 PM MST Tuesday. * Affected Area...Fire Weather Zones 216, 238, and 242, as well as Zone 215 below 7500 ft. * Timing...10 AM to 5 PM for Zone 215. After 12 PM for all other zones. * Winds...West 15 to 25 mph with gusts between 30 and 45 mph. * Relative Humidity...10 to 15%. * Impacts...Any fires that develop are likely to spread rapidly. Outdoor burning should be avoided, as well as any activities that may cause sparks. 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. && $$ Rodriguez
4 follow-up statements
453 WWUS85 KBOU 210354 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 854 PM MST Mon Dec 20 2021 ...CRITICAL FIRE WEATHER CONDITIONS TUESDAY AFTERNOON... .Very dry and locally breezy conditions will result in several hours of critical fire weather conditions Tuesday afternoon for the Cheyenne Ridge, foothills, and portions of the Palmer Divide. COZ216-238-242-211200- /O.EXT.KBOU.FW.W.0026.211221T1900Z-211222T0000Z/ Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Larimer County Below 6000 Feet/Northwest Weld County- Northeast Weld County- 854 PM MST Mon Dec 20 2021 ...RED FLAG WARNING NOW IN EFFECT FROM NOON TO 5 PM MST TUESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE CHEYENNE RIDGE, FOOTHILLS, AND PORTIONS OF THE PALMER DIVIDE... * Affected Area...Fire Weather Zones 216, 238 and 242. * Timing...12 PM to 5 PM MST. * Winds...West 15 to 25 mph with gusts up to 45 mph. * Relative Humidity...10 to 15 percent. * Impacts...Any fires that develop are likely to spread rapidly. Outdoor burning should be avoided, as well as any activities that may cause sparks. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ COZ215-211200- /O.CON.KBOU.FW.W.0026.211221T1600Z-211222T0000Z/ Larimer and Boulder Counties Between 6000 and 9000 Feet- 854 PM MST Mon Dec 20 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM TO 5 PM MST TUESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTHERN FOOTHILLS BELOW 7500 FT... * Affected Area...Fire Weather Zone 215 below 7500 ft. * Timing...9 AM to 5 PM MST. * Winds...West 20 to 30 mph with gusts of 30 to 50 mph. * Relative Humidity...10 to 15 percent. * Impacts...Any fires that develop are likely to spread rapidly. Outdoor burning should be avoided, as well as any activities that may cause sparks. 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. && $$
582 WWUS85 KBOU 211103 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 403 AM MST Tue Dec 21 2021 ...CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON... .Very dry and locally breezy conditions will result in several hours of critical fire weather conditions this afternoon for the Cheyenne Ridge, foothills, and portions of the Palmer Divide. COZ215-211915- /O.CON.KBOU.FW.W.0026.211221T1600Z-211222T0000Z/ Larimer and Boulder Counties Between 6000 and 9000 Feet- 403 AM MST Tue Dec 21 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTHERN FOOTHILLS BELOW 7500 FT... * Affected Area...Fire Weather Zone 215. * Timing...9 AM to 5 PM MST. * Winds...West 25 to 35 mph with gusts up to 65 mph. * Relative Humidity...As low as 13 percent. * Impacts...Any fires that develop are likely to spread rapidly. Outdoor burning should be avoided, as well as any activities that may cause sparks. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ COZ216-238-242-211915- /O.CON.KBOU.FW.W.0026.211221T1900Z-211222T0000Z/ Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Larimer County Below 6000 Feet/Northwest Weld County- Northeast Weld County- 403 AM MST Tue Dec 21 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE CHEYENNE RIDGE, FOOTHILLS, AND PORTIONS OF THE PALMER DIVIDE... * Affected Area...Fire Weather Zones 216, 238 and 242. * Timing...12 PM to 5 PM MST. * Winds...West 15 to 25 mph with gusts up to 45 mph. * Relative Humidity...As low as 11 percent. * Impacts...Any fires that develop are likely to spread rapidly. Outdoor burning should be avoided, as well as any activities that may cause sparks. 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. && $$
049 WWUS85 KBOU 212114 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 214 PM MST Tue Dec 21 2021 ...CRITICAL FIRE WEATHER CONDITIONS THROUGH LATE AFTERNOON... COZ215-216-238-242-220000- /O.CON.KBOU.FW.W.0026.000000T0000Z-211222T0000Z/ Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Larimer County Below 6000 Feet/Northwest Weld County- Northeast Weld County- 214 PM MST Tue Dec 21 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE CHEYENNE RIDGE, FOOTHILLS, AND PORTIONS OF THE PALMER DIVIDE... * Affected Area...Fire Weather Zones 215 (below 7500 feet), 216, 238 and 242. * Timing...Through 5 PM. * Winds...West 15 to 25 mph with gusts up to 45 mph. * Relative Humidity...10 to 15%. * Impacts...Any fires that develop are likely to spread rapidly. Outdoor burning should be avoided, as well as any activities that may cause sparks. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
705 WWUS85 KBOU 220002 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 502 PM MST Tue Dec 21 2021 COZ215-216-238-242-220115- /O.EXP.KBOU.FW.W.0026.000000T0000Z-211222T0000Z/ Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Larimer County Below 6000 Feet/Northwest Weld County- Northeast Weld County- 502 PM MST Tue Dec 21 2021 ...RED FLAG WARNING HAS EXPIRED AT 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE CHEYENNE RIDGE, FOOTHILLS, AND PORTIONS OF THE PALMER DIVIDE... Although the Red Flag Warning has expired, the recovery overnight will be minimal. Consequently the fire danger will remain elevated overnight in spite of the cooler temperatures and somewhat improved humidities. $$
Nearby
Red Flag Warnings in Colorado, 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.