Alert archive / Colorado / Red Flag Warnings in 2023

Red Flag Warning 8, NWS Denver/Boulder, CO

April 1, 202310 counties in Colorado

NWS Denver/Boulder, CO issued this red flag warning at Apr 1, 2023, 2:31 PM MDT for 10 counties in Colorado. It took effect at Apr 2, 2023, 11:00 AM MDT. It was in force for 9 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
Apr 1, 2023, 2:31 PM MDT (20:31 UTC)
In effect from
Apr 2, 2023, 11:00 AM MDT
Expired
Apr 2, 2023, 8:00 PM MDT
In force
9 hr
Issued by
NWS Denver/Boulder, CO

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Jefferson County, CO, Lincoln County, CO, Park County, CO

The radar

The Denver radar (KFTG), 30 km from the middle of the area, began a volume at 20:35 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

Grand Junction, CO (KGJT), launched 12:00Z, 8.5 hours before the alert went out and 326 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, Grand Junction, CO at 12:00Z on 2023-04-01Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2023-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 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
1829 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
241 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

727 
WWUS85 KBOU 012031
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
231 PM MDT Sat Apr 1 2023

COZ241-246-247-020445-
/O.UPG.KBOU.FW.A.0005.230402T1800Z-230403T0200Z/
/O.NEW.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
/O.CON.KBOU.FW.W.0007.000000T0000Z-230402T0200Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
231 PM MDT Sat Apr 1 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND 
ADJACENT PLAINS EAST AND SOUTH... 
...RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM MDT SUNDAY FOR 
WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND ADJACENT 
PLAINS EAST AND SOUTH...

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 8 PM MDT Sunday. The Fire Weather Watch is no
longer in effect.

* Affected Area...Fire Weather Zones 241, 246 and 247.

* Timing...Until 8 PM MDT today. From 11 AM to 8 PM MDT on Sunday.

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

* Relative Humidity...As low as 10 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

&&

$$

COZ214-020445-
/O.NEW.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
/O.CON.KBOU.FW.W.0007.000000T0000Z-230402T0200Z/
Central and Southeast Park County-
231 PM MDT Sat Apr 1 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR SOUTH PARK... 
...RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM MDT SUNDAY FOR 
WIND AND LOW RELATIVE HUMIDITY FOR 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 11 AM to 8 PM MDT Sunday.

* Affected Area...Fire Weather Zone 214.

* Timing...Until 8pm MDT today. From 11 AM to 8 PM MDT Sunday.

* Winds...West 25 to 35 mph with gusts up to 50 mph.

* Relative Humidity...As low as 15 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

&&

$$
5 follow-up statements
838 
WWUS85 KBOU 020155
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
755 PM MDT Sat Apr 1 2023

COZ214-241-246-247-021000-
/O.CAN.KBOU.FW.W.0007.000000T0000Z-230402T0200Z/
/O.CON.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
Central and Southeast Park County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
755 PM MDT Sat Apr 1 2023

......RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM MDT SUNDAY FOR 
WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND ADJACENT 
PLAINS EAST AND SOUTH AS WELL AS SOUTH PARK...

...RED FLAG WARNING HAS EXPIRED THIS EVENING FOR WIND AND LOW 
RELATIVE HUMIDITY FOR SOUTH PARK...

The National Weather Service in Denver has cancelled the Red Flag
Warning.

* Affected Area...Fire Weather Zones 214, 241, 246 and 247.

* Timing...Until 8pm MDT today. From 11 AM to 8 PM MDT Sunday.

* Winds...West 20 to 30 mph with gusts up to 50 mph.

* Relative Humidity...As low as 7 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

&&

$$
620 
WWUS85 KBOU 020950
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
350 AM MDT Sun Apr 2 2023

COZ241-246-247-022100-
/O.NEW.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
/O.CON.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
350 AM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 
8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR FOR 
THE PALMER DIVIDE AND SOUTH PARK...FIRE WEATHER ZONES
214..241..246..247

...FIRE WEATHER WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH
MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER
DIVIDE REGION...FIRE WEATHER ZONES 241..246..247. 

The National Weather Service in Denver has issued a Fire Weather
Watch for wind and low relative humidity, which is in effect from
Monday afternoon through Monday evening.

* Affected Area...Fire Weather Zones 241, 246 and 247.

* Timing...11 am until 8pm MDT today. From noon to 8 PM MDT 
  Monday.

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

* Relative Humidity...5 to 15 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

COZ214-022100-
/O.CON.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
Central and Southeast Park County-
350 AM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR SOUTH
PARK...

* Affected Area...Fire Weather Zone 214.

* Timing...11 AM to 8 PM MDT today.

* Winds...West 20 to 30 mph with gusts up to 50 mph.

* Relative Humidity...10 to 20 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

&&

$$
744 
WWUS85 KBOU 021256
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
656 AM MDT Sun Apr 2 2023

COZ239-240-022200-
/O.EXA.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
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-
656 AM MDT Sun Apr 2 2023

...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT
THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE DENVER
METRO AREA...

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 8 PM MDT this evening.

* Affected Area...Fire Weather Zones 239 and 240.

* Timing...11 am until 8pm MDT today.

* Winds...West 15 to 20 mph with gusts up to 30 mph.

* Relative Humidity...10 to 15 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

&&

$$

COZ241-246-247-022200-
/O.CON.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
/O.CON.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
656 AM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE
PALMER DIVIDE AND ADJACENT PLAINS TO THE EAST...

...FIRE WEATHER WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON 
THROUGH MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE
PALMER DIVIDE AND ADJACENT PLAINS TO THE EAST...

* Affected Area...Fire Weather Zones 241, 246 and 247.

* Timing...11 am until 8pm MDT today for the Red Flag Warning.
  From noon to 8 PM MDT Monday for the Fire Weather Watch.

* Winds...For today, west 15 to 25 mph with gusts up to 35 mph.
  For Monday, southwest 20 to 30 mph, with gusts up to 45 mph.

* Relative Humidity...10 to 15 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

COZ214-022200-
/O.CON.KBOU.FW.W.0008.230402T1700Z-230403T0200Z/
Central and Southeast Park County-
656 AM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR SOUTH
PARK...

* Affected Area...Fire Weather Zone 214.

* Timing...11 AM to 8 PM MDT today.

* Winds...West 20 to 30 mph with gusts up to 45 mph.

* Relative Humidity...12 to 20 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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
213 
WWUS85 KBOU 021935
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
135 PM MDT Sun Apr 2 2023

COZ214-030600-
/O.EXA.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
/O.CON.KBOU.FW.W.0008.000000T0000Z-230403T0200Z/
Central and Southeast Park County-
135 PM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR SOUTH PARK...

...FIRE WEATHER WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH 
MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR SOUTH PARK...

The National Weather Service in Denver has issued a Fire Weather
Watch for wind and low relative humidity, which is in effect from
Monday afternoon through Monday evening.

* Affected Area...Fire Weather Zone 214.

* Timing...Unit 8 PM MDT this evening for the Red Flag Warning. 
  From noon to 8 PM MDT Monday for the Fire Weather Watch.

* Winds...For today, west 20 to 30 mph with gusts up to 45 mph.
  For Monday, southwest 25 to 35 mph, with gusts up to 50 mph.

* Relative Humidity...10 to 15 percent this afternoon. 15 to 20%
  on Monday.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

COZ241-246-247-030600-
/O.CON.KBOU.FW.W.0008.000000T0000Z-230403T0200Z/
/O.CON.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
135 PM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PALMER DIVIDE AND 
ADJACENT PLAINS TO THE EAST... 

...FIRE WEATHER WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON 
THROUGH MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR 
THE PALMER DIVIDE AND ADJACENT PLAINS TO THE EAST...

* Affected Area...Fire Weather Zones 241, 246 and 247.

* Timing...Through 8 PM MDT this evening for the Red Flag 
  Warning. From noon to 8 PM MDT Monday for the Fire Weather 
  Watch.

* Winds...For today, west 15 to 25 mph with gusts up to 35 mph. 
  For Monday, southwest 20 to 30 mph, with gusts up to 45 mph.

* Relative Humidity...10 to 15 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

COZ239-240-030200-
/O.CON.KBOU.FW.W.0008.000000T0000Z-230403T0200Z/
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-
135 PM MDT Sun Apr 2 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE DENVER METRO...

* Affected Area...Fire Weather Zones 239 and 240.

* Timing...Until 8 PM this evening.

* Winds...West 15 to 20 mph with gusts up to 30 mph.

* Relative Humidity...10 to 15 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  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.

&&

$$

COZ216-030600-
/O.EXA.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
135 PM MDT Sun Apr 2 2023

...FIRE WEATHER WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH
MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE SOUTHERN
FOOTHILLS...

The National Weather Service in Denver has issued a Fire Weather
Watch for wind and low relative humidity, which is in effect from
Monday afternoon through Monday evening.

* Affected Area...Fire Weather Zone 216.

* Timing...Noon to 8 PM MDT Monday.

* Winds...Southwest 20 to 30 mph, with gusts up to 45 mph.

* Relative Humidity...12 to 20 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  sparks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

Rodriguez
181 
WWUS85 KBOU 030155
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
755 PM MDT Sun Apr 2 2023

COZ214-241-246-247-031000-
/O.EXP.KBOU.FW.W.0008.000000T0000Z-230403T0200Z/
/O.CON.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
Central and Southeast Park County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
755 PM MDT Sun Apr 2 2023

...FIRE WEATHER WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR
SOUTH PARK...
...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR SOUTH PARK...

* Affected Area...Fire Weather Zones 214, 241, 246 and 247.

* Timing...Unit 8 PM MDT this evening for the Red Flag Warning. 
  From noon to 8 PM MDT Monday for the Fire Weather Watch.

* Winds...Southwest 25 to 35 mph with gusts up to 55 mph.

* Relative Humidity...As low as 9 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  sparks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

COZ239-240-030300-
/O.EXP.KBOU.FW.W.0008.000000T0000Z-230403T0200Z/
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-
755 PM MDT Sun Apr 2 2023

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR THE DENVER METRO...

$$

COZ216-031000-
/O.CON.KBOU.FW.A.0006.230403T1800Z-230404T0200Z/
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
755 PM MDT Sun Apr 2 2023

...FIRE WEATHER WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE
SOUTHERN FOOTHILLS...

* Affected Area...Fire Weather Zone 216.

* Timing...Noon to 8 PM MDT Monday.

* Winds...Southwest 25 to 35 mph with gusts up to 55 mph.

* Relative Humidity...As low as 16 percent.

* Impacts...Conditions will be favorable for rapid fire spread. 
  Avoid outdoor burning and any activities that may produce 
  sparks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings.

&&

$$

What forecasters said that day

The local office's own words before this red flag warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this red flag warning went out at Apr 1, 12:25 PM MDT, 2 hours 6 minutes earlier.

Area forecast discussion, Apr 1, 12:25 PM MDT, 2 hours 6 minutes before
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1225 PM MDT Sat Apr 1 2023

.UPDATE...
Issued at 1038 AM MDT Sat Apr 1 2023

The forecast for a mostly sunny day with no precipitation remains
on track. The focus for today will be fire weather conditions as
there is a Red Flag Warning out and there is potential for
expanding the warning area. Northwest winds have poked out onto
the plains in Boulder and Jefferson Counties in spots. For
example, Boulder Airport (KBDU) had a gust to 29 mph last hour with
relative humidity down to 19 percent. It is almost a certainty
that the Denver metro along with eastern Boulder and Jefferson
Counties will see relative humidity below 15 this afternoon which
would meet the humidity part of the Red Flag criteria. However, it
remains uncertain as to whether the winds will be strong enough
to meet that part of the Red Flag criteria. There may be brief
pockets of wind that develop across those aforementioned areas
with gusts up to 30 mph. The current thinking is that these winds
will not be persistent enough to warrant a Red Flag Warning
extension but the winds will be monitored closely. If west winds
end up being stronger and more persist, then our office may end up
putting a warning out.

&&

.SHORT TERM...(Today and tonight)
Issued at 312 AM MDT Sat Apr 1 2023

Today, northeast Colorado will be under a weak ridge with
decreasing subsidence and increasing zonal flow aloft as the ridge
flattens out. It will be mostly clear, and warm across the plains
with highs in the 60s. Some cooler air will linger over the high
country, and highs will be in the 20s to 40s. There will be
stability over the ridgeline and some weak mountain wave
amplification, as well as mixing to between 700 and 600 mb. Expect
a breezy afternoon, not nearly so bad as yesterday but still with
impacts to sensible weather. With lee troughing as well, the
surface flow should turn a bit more southerly and winds will be
generally southwesterly. Peak afternoon gusts are forecast 20 to
35 mph across the plains and 30 to 50 mph across the high country.
It will also be dry across the plains again with afternoon
minimum humidity generally 10 to 20 percent, and particularly low
humidity across much of the southern part of the forecast. This is
also the area of strongest wind for the lower elevations, which
means widespread critical and elevated fire weather conditions. We
maintain our Red Flag Warning for South Park, the Palmer Divide
and adjacent plains south and east, valid from 11 AM to 8 PM MDT.

Tonight, Colorado between two passing shortwaves and there may
briefly be a little bit of synoptic ascent to minimal effect. Very
light orographic snow showers are possible for the northern Park
and Front Range mountains. Winds decrease over the plains with
decoupling in the evening, but continue to increase in the
mountains as zonal flow continues to increase beneath persistent
ridgeline stability and and the mountain wave continues to
amplify. Cross sections show the wave with some reflection to
lower elevations, but it likely won't be able to break inversions
overnight. In the mountains and higher foothills, expect
widespread peak gusts 50 to 60 mph and up to around 70 mph for the
higher, more exposed areas. We have forecast marginal warning
criteria overnight for a limited area and duration, so we are
going to refrain from any highlights for now and reassess with the
next forecast package. Overnight lows should be near normal
again, in the 20s and 30s across the plains and teens and 20s
across the high country.

.LONG TERM...(Sunday through Friday)
Issued at 312 AM MDT Sat Apr 1 2023

On Sunday there will be a moderate to strong westerly flow aloft
over Colorado with the main jet core north of Colorado across
Wyoming. The mountain top flow will shift more southwesterly
during the day with the highest winds expected over the mountains
peaks with the cross barrier flow of 40-50kt. Moisture will begin
to seep into the far northern mountains and given southwest flow
will favor some showers over zone 31 in proximity to Rabbit Ears
Pass. Temperatures will also remain quite warm with readings in
the 60s across the plains but could see some slight cooling over
the far northeast plains as weak cold front moves across the
northeast plains.

On Monday, the next Pacific storm system drops into the Great
Basin with an increasing southwest flow aloft over Colorado.
Expect increasing moisture and more favorable QG ascent over the
mountains but snow showers still focused over western Jackson
county. The upper low then poised to track northeast across
southern Wyoming and into Nebraska through Tuesday with the best
chance of mountain snow showers and cooler temperatures over all
of Northern Colorado. The models are fairly consistent with this
track and this usually spells limited moisture and chances for
showers across lower elevations. However, a cold front ushers
southward Monday night with developing northeast winds and
increasing low level moisture. This will leave for a much cooler
day on Tuesday with a chance of showers with increasing QG ascent.
By later Tuesday as the low lifts out over Nebraska, there will
be increasing subsidence over much of the state. Orographic
snowfall will increase over the mountains as winds shift to a more
favorable northwest flow regime.

Another system will be on the heels of the Tuesday low with impacts
across northern Colorado on Wednesday through early Thursday with
more snow for the mountains and a chance of showers and continued
coolness over the plains. Dry and warmer towards the end of next
week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1220 AM MDT Sat Apr 1 2023

West winds have failed to develop early this afternoon at all
three terminals so light southerly winds were kept until 20-21Z
when the west winds are expected to finally develop. However,
these west winds are not a certainty and winds could stay light
and out of the southeast for much of the day. Tonight, drainage
winds will develop. Tomorrow, there is higher confidence that west
winds will develop by the mid afternoon since there is better
flow aloft. There are no ceiling or visibility concerns.

&&

.FIRE WEATHER...
Issued at 312 AM MDT Sat Apr 1 2023

This afternoon, it will be warmer with lower humidity. Winds will
be lighter, but still reach Red Flag Criteria over the southern
portions of our forecast area from Park County eastward across the
Palmer Divide. Afternoon Gusts 25 to 35 mph will coincide with
minimum humidity of 10 to 20 percent across the warning area. We
maintain our Red Flag Warning for South Park, the Palmer Divide
and adjacent plains south and east, valid from 11 AM to 8 PM MDT.

Look for more near critical fire weather conditions on Sunday
afternoon across the Palmer Divide with gusty winds and low
humidities. Could see similar conditions again on Monday afternoon
over similar areas. Finally a break from Tuesday onward as cooler
temperatures and higher humidities develop over much of the area.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for COZ214-241-246-
247.

Fire Weather Watch from Sunday afternoon through Sunday evening
for COZ241-246-247.

&&

UPDATE...Danielson
SHORT TERM...EJD
LONG TERM...Entrekin
AVIATION...Danielson
FIRE WEATHER...Entrekin/EJD
Hazardous weather outlook, Apr 1, 10:52 AM MDT, 3 hours 39 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1052 AM MDT Sat Apr 1 2023

COZ030>051-021700-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-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-
Central and Southeast Park County-
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-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1052 AM MDT Sat Apr 1 2023

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Today, critical and elevated fire weather conditions are expected
across much of the plains. A Red Flag Warning is in effect for
South Park, the Palmer Divide and adjacent plains south and east,
valid from 11 AM to 8 PM MDT. Wind gusts up to 25 to 35 mph will
coincide with minimum humidity of 10 to 20 percent creating
critical fire weather conditions.

It will be windy across the high country with gusts generally 50
to 60 mph across the mountains and higher foothills and up to
about 70 mph for the exposed peaks. These winds are expected to
last through tonight and into tomorrow.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Expect near critical to critical fire weather conditons on Sunday
afternoon over the Palmer Divide region with gusty winds and low
humidities. The next chance of snow will return to the mountains
late Monday and Tuesday, and there will be a chance of rain or
snow showers at lower elevations from Tuesday through Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed. Any reports of strong winds
will be appreciated.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 1, 3:19 AM MDTFire Weather WatchBOUArapahoe, Douglas, Elbert, Lincoln11 hr
Apr 1, 2:23 PM MDTWinter Storm WatchBOUGrand, Jackson23 hr

Nearby

Red Flag Warnings in Colorado, 2023Every red flag warning in 2023

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.