Alert archive / Colorado / Red Flag Warnings in 2021

Red Flag Warning 21, NWS Denver/Boulder, CO

November 15, 202112 counties in Colorado

NWS Denver/Boulder, CO issued this red flag warning at Nov 15, 2021, 1:21 PM MST for 12 counties in Colorado. It took effect at Nov 16, 2021, 10:00 AM MST. 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
Nov 15, 2021, 1:21 PM MST (20:21 UTC)
In effect from
Nov 16, 2021, 10:00 AM MST
Expired
Nov 16, 2021, 5:00 PM MST
In force
7 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, Park County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 36 km from the middle of the area, began a volume at 20:27 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, 8.4 hours before the alert went out and 149 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 12:00Z on 2021-11-15Temperature 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 12:00Z on 2021-11-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 179 square meters per square second.19395878Sfc1 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
3052 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
290 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

121 
WWUS85 KBOU 152021
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
121 PM MST Mon Nov 15 2021

COZ214-216-239>241-243-245-161300-
/O.NEW.KBOU.FW.W.0021.211116T1700Z-211117T0000Z/
Central and Southeast Park County-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
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-
Central and South Weld County-
Central and East Adams and Arapahoe Counties-
121 PM MST Mon Nov 15 2021

...RED FLAG WARNING IN EFFECT FROM 10 AM TO 5 PM MST TUESDAY FOR
WIND AND LOW RELATIVE HUMIDITY FOR MOST OF THE URBAN CORRIDOR AND
NEARBY PLAINS, SOUTHERN FOOTHILLS, AND SOUTH PARK...

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 to 5 PM MST Tuesday.

* Affected Area...Fire Weather Zones 214, 216, 239, 240, 241, 
  243 and 245.

* Timing...10 AM to 5 PM MST Tuesday.

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

* Relative Humidity...As low as 10 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.

&&

$$
2 follow-up statements
480 
WWUS85 KBOU 161112
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
412 AM MST Tue Nov 16 2021

COZ214-216-239>241-243-245-170000-
/O.CON.KBOU.FW.W.0021.211116T1700Z-211117T0000Z/
Central and Southeast Park County-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
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-
Central and South Weld County-
Central and East Adams and Arapahoe Counties-
412 AM MST Tue Nov 16 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR
MOST OF THE URBAN CORRIDOR AND NEARBY PLAINS, SOUTHERN FOOTHILLS,
AND SOUTH PARK...

* Affected Area...Fire Weather Zones 214, 216, 239, 240, 241, 
  243 and 245.

* Timing...10 AM to 5 PM MST Tuesday.

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

* Relative Humidity...As low as 12 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.

&&

$$
864 
WWUS85 KBOU 170004
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver CO
504 PM MST Tue Nov 16 2021


COZ214-216-239>241-243-245-170115-
/O.EXP.KBOU.FW.W.0021.000000T0000Z-211117T0000Z/
Central and Southeast Park County-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
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-
Central and South Weld County-
Central and East Adams and Arapahoe Counties-
504 PM MST Tue Nov 16 2021

...RED FLAG WARNING HAS EXPIRED FOR WINDS AND LOW RELATIVE
HUMIDITY FOR FIRE WEATHER ZONES 214, 216, 239, 240, 241, 243, AND
245...

Winds are forecast to gradually decrease this evening with
relative humidities increase by morning; therefore, the Red Flag
Warning has been allowed to expire.

$$

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.