Alert archive / Colorado / Red Flag Warnings in 2021

Red Flag Warning 3, NWS Denver/Boulder, CO

March 5, 20214 counties in Colorado

NWS Denver/Boulder, CO issued this red flag warning at Mar 5, 2021, 2:51 PM MST for 4 counties in Colorado. It took effect at Mar 6, 2021, 11:00 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
Mar 5, 2021, 2:51 PM MST (21:51 UTC)
In effect from
Mar 6, 2021, 11:00 AM MST
Expired
Mar 6, 2021, 6:00 PM MST
In force
7 hr
Issued by
NWS Denver/Boulder, CO

Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO

The radar

The Goodland radar (KGLD), 159 km from the middle of the area, began a volume at 21:56 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, 9.9 hours before the alert went out and 85 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 2021-03-05Temperature 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 2021-03-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 74 square meters per square second.193958Sfc1 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
2032 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

402 
WWUS85 KBOU 052151
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
251 PM MST Fri Mar 5 2021

COZ248>251-060600-
/O.NEW.KBOU.FW.W.0003.210306T1800Z-210307T0100Z/
Logan County-Washington County-Sedgwick County-Phillips County-
251 PM MST Fri Mar 5 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM TO 6 PM MST SATURDAY FOR
WIND AND LOW RELATIVE HUMIDITY FOR THE NORTHEAST PLAINS OF 
COLORADO...

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 to 6 PM MST Saturday.

* Affected Area...Fire Weather Zones 248, 249, 250 and 251.

* Timing... 11 AM to 6 PM MST Saturday

* Winds...South 15 to 25 mph with gusts up to 40 mph.

* Relative Humidity...As low as 12 percent.

* Impacts... Strong winds combined with low relative humidity may
  cause new fire starts to rapidly spread and grow.

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.

&&

$$
4 follow-up statements
928 
WWUS85 KBOU 060549
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
1049 PM MST Fri Mar 5 2021

COZ248>251-061800-
/O.CON.KBOU.FW.W.0003.210306T1800Z-210307T0100Z/
Logan County-Washington County-Sedgwick County-Phillips County-
1049 PM MST Fri Mar 5 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 6 PM MST
SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTHEAST
PLAINS OF COLORADO...

* Affected Area...Fire Weather Zones 248, 249, 250 and 251.

* Timing... 11 AM to 6 PM MST Saturday

* Winds...South 15 to 25 mph with gusts up to 40 mph.

* Relative Humidity...As low as 12 percent.

* Impacts... Strong winds combined with low relative humidity 
  may cause new fire starts to rapidly spread and grow.

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.

&&

$$

Gimmestad
390 
WWUS85 KBOU 061154
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
454 AM MST Sat Mar 6 2021

COZ248>251-062200-
/O.CON.KBOU.FW.W.0003.210306T1800Z-210307T0100Z/
Logan County-Washington County-Sedgwick County-Phillips County-
454 AM MST Sat Mar 6 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
6 PM MST THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE
NORTHEAST PLAINS OF COLORADO...

* Affected Area...Northeastern Colorado from Sterling and Akron
  eastward...Fire Weather Zones 248, 249, 250 and 251.

* Timing... 11 AM to 6 PM MST Saturday

* Winds...South 15 to 25 mph with gusts up to 40 mph.

* Relative Humidity...As low as 11 percent.

* Impacts... Strong winds combined with low relative humidity 
  may cause new fire starts to rapidly spread and grow.

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.

&&

$$

Gimmestad
004 
WWUS85 KBOU 062151
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
251 PM MST Sat Mar 6 2021

COZ248>251-070100-
/O.CON.KBOU.FW.W.0003.000000T0000Z-210307T0100Z/
Logan County-Washington County-Sedgwick County-Phillips County-
251 PM MST Sat Mar 6 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 PM MST THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTHEAST PLAINS OF
COLORADO...

* Affected Area...Fire Weather Zones 248, 249, 250 and 251.

* Timing... Until 6 PM MST this evening.

* Winds...South 15 to 25 mph with gusts up to 40 mph.

* Relative Humidity...As low as 12 percent.

* Impacts... Strong winds combined with low relative humidity 
  may cause new fire starts to rapidly spread and grow.

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.

&&

$$
293 
WWUS85 KBOU 070105
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
605 PM MST Sat Mar 6 2021

COZ248>251-070215-
/O.EXP.KBOU.FW.W.0003.000000T0000Z-210307T0100Z/
Logan County-Washington County-Sedgwick County-Phillips County-
605 PM MST Sat Mar 6 2021

...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE
HUMIDITY FOR THE NORTHEAST PLAINS OF COLORADO...

Winds have decreased this evening, and relative humidities have
recovered to 20-25 percent, allowing the warning 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.