Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 24, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Dec 5, 2021, 3:21 AM MST for 16 counties in Colorado. It took effect at Dec 5, 2021, 10:00 AM MST. It was in force for 5 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 5, 2021, 3:21 AM MST (10:21 UTC)
- In effect from
- Dec 5, 2021, 10:00 AM MST
- Expired
- Dec 5, 2021, 3:00 PM MST
- In force
- 5 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Clear Creek County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Lincoln County, CO, Morgan County, CO, Park County, CO, Washington County, CO, Weld County, CO
The radar
The Denver radar (KFTG), 15 km from the middle of the area, began a volume at 10:24 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 00:00Z, 10.4 hours before the alert went out and 128 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
- 3432 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 34 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
332 WWUS85 KBOU 051021 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 321 AM MST Sun Dec 5 2021 ...DANGEROUS FIRE WEATHER CONDITIONS LATE MORNING TO MID AFTERNOON OVER THE PALMER DIVIDE AND EASTERN PLAINS...FIRE ZONES 216, 241, 245, 246, AND 249... .STRONG GUSTY WINDS WILL DEVELOP LATE THIS MORNING AS A COLD FRONT MOVES INTO THE AREA. WARM TEMPERATURES AHEAD OF THE COLD FRONT WILL GENERATE RELATIVE HUMIDITIES IN THE LOW TEENS. RED FLAG CRITERIA OF WIND GUSTS OVER 25 MPH AND RELATIVE HUMIDITY BELOW 15 PERCENT WILL BE ACROSS MAJORITY OF 246, AND LIMITED TO SOUTHERN PORTIONS OF FIRE ZONES 216, 245, AND 249, AND EASTERN 241. COZ216-241-245-246-249-052100- /O.NEW.KBOU.FW.W.0024.211205T1700Z-211205T2100Z/ Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Elbert/Central and East Douglas Counties Above 6000 Feet- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County-Washington County- 321 AM MST Sun Dec 5 2021 ...RED FLAG WARNING IN EFFECT FROM 10 AM THIS MORNING TO 2 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND EASTERN PLAINS... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 10 AM this morning to 2 PM MST this afternoon. * Affected Area...Fire Weather Zones 216, 241, 245, 246 and 249. * Timing...10 am to 2 pm. * Winds...Northwest 15 to 25 mph with gusts up to 40 mph. * Relative Humidity...As low as 13 percent. * Impacts...Conditions will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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. && $$ HANSON
2 follow-up statements
047 WWUS85 KBOU 051751 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 1051 AM MST Sun Dec 5 2021 ...DANGEROUS FIRE WEATHER CONDITIONS LATE THIS MORNING TO MID AFTERNOON OVER THE PALMER DIVIDE AND EASTERN PLAINS...FIRE ZONES 216, 241, 245, 246, AND 249... .STRONG GUSTY WINDS WILL DEVELOP LATE THIS MORNING AS A COLD FRONT MOVES INTO THE AREA. WARM TEMPERATURES AHEAD OF THE COLD FRONT WILL GENERATE RELATIVE HUMIDITIES IN THE LOW TEENS. RED FLAG CRITERIA OF WIND GUSTS OVER 25 MPH AND RELATIVE HUMIDITY BELOW 15 PERCENT WILL BE ACROSS MAJORITY OF 246, AND LIMITED TO SOUTHERN PORTIONS OF FIRE ZONES 216, 245, AND 249, AND EASTERN 241. COZ238>240-242>244-052200- /O.EXB.KBOU.FW.W.0024.000000T0000Z-211205T2200Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County-Northeast Weld County- Central and South Weld County-Morgan County- 1051 AM MST Sun Dec 5 2021 ...RED FLAG WARNING IN EFFECT UNTIL 3 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PLAINS OF NORTHEAST COLORADO... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect until 3 PM MST this afternoon. * Affected Area...Fire Weather Zones 238, 239, 240, 242, 243 and 244. * Timing...Now through 3 pm. * Winds...Northwest 20 to 35 mph with gusts up to 50 mph. * Relative Humidity...As low as 8 percent. * Impacts...Conditions will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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. && $$ COZ216-241-245-246-249-052200- /O.EXT.KBOU.FW.W.0024.000000T0000Z-211205T2200Z/ Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Elbert/Central and East Douglas Counties Above 6000 Feet- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County-Washington County- 1051 AM MST Sun Dec 5 2021 ...RED FLAG WARNING NOW IN EFFECT UNTIL 3 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND ADJACENT EASTERN PLAINS... * Affected Area...Fire Weather Zones 216, 241, 245, 246 and 249. * Timing...Now through 3 pm. * Winds...Northwest 20 to 35 mph with gusts up to 50 mph. * Relative Humidity...As low as 8 percent. * Impacts...Conditions will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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. && $$
612 WWUS85 KBOU 052210 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 310 PM MST Sun Dec 5 2021 COZ216-238>246-249-052315- /O.EXP.KBOU.FW.W.0024.000000T0000Z-211205T2200Z/ Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County-Washington County- 310 PM MST Sun Dec 5 2021 ...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND ADJACENT EASTERN PLAINS... A cold front will continue to sweep south and southwest across the plains with increasing humidity levels. There will be brief strong northeast winds up to 45 mph with the front, then winds decreasing through the evening. $$
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.