Alert archive / Colorado / Red Flag Warnings in 2021

Red Flag Warning 27, NWS Denver/Boulder, CO

December 22, 20219 counties in Colorado

NWS Denver/Boulder, CO issued this red flag warning at Dec 22, 2021, 3:11 AM MST for 9 counties in Colorado. It took effect at Dec 22, 2021, 5:00 AM MST. It was in force for 12 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 22, 2021, 3:11 AM MST (10:11 UTC)
In effect from
Dec 22, 2021, 5:00 AM MST
Expired
Dec 22, 2021, 5:00 PM MST
In force
12 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, Logan County, CO, Park County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 46 km from the middle of the area, began a volume at 10:10 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, 10.2 hours before the alert went out and 155 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.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2021-12-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2021-12-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.1939587897117136156Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3882 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

029 
WWUS85 KBOU 221011
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
311 AM MST Wed Dec 22 2021

COZ242-248-221815-
/O.NEW.KBOU.FW.W.0027.211222T1800Z-211223T0000Z/
Northeast Weld County-Logan County-
311 AM MST Wed Dec 22 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO 5 PM MST
THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR HIGHER
TERRAIN NEAR THE WYOMING/NEBRASKA BORDER...

The National Weather Service in Denver has issued a Red Flag
Warning for wind and low relative humidity, which is in effect
from 11 AM this morning to 5 PM MST this afternoon.

* Affected Area...Fire Weather Zones 242 and 248.

* Timing...11 am to 5 pm.

* Winds...Southwest 10 to 20 mph with gusts up to 30 mph.

* Relative Humidity...As low as 7 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.

&&

$$

COZ214>216-238-221815-
/O.NEW.KBOU.FW.W.0027.211222T1200Z-211223T0000Z/
Central and Southeast Park County-
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-
311 AM MST Wed Dec 22 2021

...RED FLAG WARNING IN EFFECT UNTIL 5 PM MST THIS AFTERNOON FOR
WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS AND
PARK COUNTY...

The National Weather Service in Denver has issued a Red Flag
Warning for wind and low relative humidity, which is in effect
until 5 PM MST this afternoon.

* Affected Area...Fire Weather Zones 214, 215, 216 and 238.

* Timing...Until 5 pm this afternoon. 

* Winds...West 15 to 30 mph with gusts up to 60 mph.

* Relative Humidity...As low as 8 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.

&&

$$
2 follow-up statements
083 
WWUS85 KBOU 221832
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
1132 AM MST Wed Dec 22 2021

COZ242-248-230000-
/O.CON.KBOU.FW.W.0027.000000T0000Z-211223T0000Z/
Northeast Weld County-Logan County-
1132 AM MST Wed Dec 22 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR HIGHER TERRAIN
NEAR THE WYOMING/NEBRASKA BORDER...

* Affected Area...Fire Weather Zones 242 and 248.

* Timing...11 am to 5 pm.

* Winds...Southwest 15 to 25 mph with gusts up to 35 mph.

* Relative Humidity...As low as 7 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.

&&

$$

COZ214>216-238-230000-
/O.CON.KBOU.FW.W.0027.000000T0000Z-211223T0000Z/
Central and Southeast Park County-
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-
1132 AM MST Wed Dec 22 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE
FOOTHILLS AND PARK COUNTY...

* Affected Area...Fire Weather Zones 214, 215, 216 and 238.

* Timing...Until 5 pm this afternoon.

* Winds...West 15 to 25 mph with gusts up to 45 mph.

* Relative Humidity...As low as 8 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.

&&

$$
669 
WWUS85 KBOU 222357
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
457 PM MST Wed Dec 22 2021

COZ242-248-230100-
/O.EXP.KBOU.FW.W.0027.000000T0000Z-211223T0000Z/
Northeast Weld County-Logan County-
457 PM MST Wed Dec 22 2021

...RED FLAG WARNING WILL EXPIRE AT 5 PM MST THIS AFTERNOON FOR
WIND AND LOW RELATIVE HUMIDITY FOR HIGHER TERRAIN
NEAR THE WYOMING/NEBRASKA BORDER...

The Red Flag Warning will be allowed to expire.

$$

COZ214>216-238-230100-
/O.EXP.KBOU.FW.W.0027.000000T0000Z-211223T0000Z/
Central and Southeast Park County-
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-
457 PM MST Wed Dec 22 2021

...RED FLAG WARNING WILL EXPIRE AT 5 PM MST THIS AFTERNOON FOR
WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS AND 
PARK COUNTY...

The Red Flag Warning will be allowed to expire.

$$

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 22, 2:47 AM MSTWinter Storm WatchBOUBoulder, Grand, Jackson, Larimer12 hr
Dec 22, 2:33 PM MSTWinter Storm WarningBOUBoulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more68 hr
Dec 22, 2:33 PM MSTWinter Weather AdvisoryBOUBoulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 2 more66 hr

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.