Red Flag Warning 26, NWS Denver/Boulder, CO

573 
WWUS85 KBOU 260125
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
725 PM MDT Fri Sep 25 2020

Very warm and dry conditions are expected today and Saturday. Red
flag conditions are expected this afternoon for strong winds and
low relative humidity. The strongest winds and driest conditions
are expected east of the Divide across Larimer County, though
favorable conditions for rapid fire growth are possible across
all of the warned area.

Strong winds will again occur on Saturday as well. Gusty winds
will develop in the foothills and South Park early Saturday
morning, then spread across the plains along the Wyoming border
and southward in the afternoon. Relative humidities will remain 
fairly low with minimal recovery in the foothills overnight. 
Consequently, a Red Flag Warning has been issued for these areas.

COZ239-243-244-260930-
/O.EXA.KBOU.FW.W.0026.200926T1800Z-200927T0100Z/
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-Central and South Weld County-Morgan County-
725 PM MDT Fri Sep 25 2020

...RED FLAG WARNING IN EFFECT FROM NOON TO 7 PM MDT SATURDAY FOR
WIND AND LOW RELATIVE HUMIDITY FOR BOULDER, JEFFERSON, SOUTHERN
WELD AND MORGAN COUNTIES...

The National Weather Service in Denver has issued a Red Flag
Warning FOR WIND AND LOW RELATIVE HUMIDITY, which is in effect
from noon to 7 PM MDT Saturday.

* Affected Area...Fire Weather Zones 239, 243 and 244.

* Timing...Saturday from Noon to 7 PM.

* Winds...Northwest 15 to 20 mph with gusts up to 35 mph.

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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>216-260930-
/O.CON.KBOU.FW.W.0025.000000T0000Z-200926T0200Z/
/O.CON.KBOU.FW.W.0026.200926T1500Z-200927T0100Z/
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-
725 PM MDT Fri Sep 25 2020

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

...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM TO 7 PM MDT 
SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FRONT RANGE 
FOOTHILLS AND SOUTH PARK...

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

* Timing...12 PM through 8 PM this evening, then Saturday from 9 
  AM to 7 PM MDT.

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

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

* Impacts...Rapid growth of existing fires and new fire starts 
  will be possible due to the gusty winds and very low humidity.

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.

&&

$$

COZ211>213-217-218-260230-
/O.CON.KBOU.FW.W.0025.000000T0000Z-200926T0200Z/
Jackson County Below 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Grand and Summit Counties Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
725 PM MDT Fri Sep 25 2020

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR NORTHERN AND CENTRAL
MOUNTAINS AND HIGH MOUNTAIN VALLEYS...

* Affected Area...Fire Weather Zones 211, 212, 213, 217 and 218.

* Timing...12 PM through 8 PM this evening.

* Winds...West 10 to 15 mph with gusts up to 30 mph.

* Relative Humidity...As low as 13 percent.

* Impacts...Rapid growth of existing fires and new fire starts 
  will be possible due to the gusty winds and very low humidity.

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.

&&

$$

COZ238-242-248-250-251-260930-
/O.CON.KBOU.FW.W.0026.200926T1800Z-200927T0100Z/
Larimer County Below 6000 Feet/Northwest Weld County-
Northeast Weld County-Logan County-Sedgwick County-
Phillips County-
725 PM MDT Fri Sep 25 2020

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 7 PM MDT
SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE LOWER
ELEVATIONS OF LARIMER COUNTY AS WELL AS NORTHERN WELD, LOGAN,
SEDGWICK AND PHILLIPS COUNTIES...

* Affected Area...Fire Weather Zones 238, 242, 248, 250 and 251.

* Timing...Saturday from Noon to 7 PM.

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

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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.

&&

$$

171 
WWUS85 KBOU 260159
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
759 PM MDT Fri Sep 25 2020

Very warm and dry conditions are expected today and Saturday. Red
flag conditions are expected this afternoon for strong winds and
low relative humidity. The strongest winds and driest conditions
are expected east of the Divide across Larimer County, though
favorable conditions for rapid fire growth are possible across
all of the warned area.

Strong winds will again occur on Saturday as well. Gusty winds
will develop in the foothills and South Park early Saturday
morning, then spread across the plains along the Wyoming border
and southward in the afternoon. Relative humidities will remain
fairly low with minimal recovery in the foothills overnight.
Consequently, a Red Flag Warning has been issued for these areas.

COZ214>216-261000-
/O.EXP.KBOU.FW.W.0025.000000T0000Z-200926T0200Z/
/O.CON.KBOU.FW.W.0026.200926T1500Z-200927T0100Z/
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-
759 PM MDT Fri Sep 25 2020

...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM TO 7 PM MDT
SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FRONT RANGE
FOOTHILLS AND SOUTH PARK...
...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR FRONT RANGE FOOTHILLS AND SOUTH
PARK...

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

* Timing...12 PM through 8 PM this evening, then Saturday from 9 
  AM to 7 PM MDT.

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

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

* Impacts...Rapid growth of existing fires and new fire starts 
  will be possible due to the gusty winds and very low humidity.

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.

&&

$$

COZ211>213-217-218-260300-
/O.EXP.KBOU.FW.W.0025.000000T0000Z-200926T0200Z/
Jackson County Below 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Grand and Summit Counties Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
759 PM MDT Fri Sep 25 2020

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR NORTHERN AND CENTRAL MOUNTAINS AND
HIGH MOUNTAIN VALLEYS...

Weather conditions that prompted the Red Flag Warning have ended.
However, elevated fire weather conditions still exist and caution
is advised. 

$$

COZ238-239-242>244-248-250-251-261000-
/O.CON.KBOU.FW.W.0026.200926T1800Z-200927T0100Z/
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-Northeast Weld County-Central and South Weld County-
Morgan County-Logan County-Sedgwick County-Phillips County-
759 PM MDT Fri Sep 25 2020

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 7 PM MDT
SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE LOWER
ELEVATIONS OF LARIMER COUNTY AS WELL AS NORTHERN WELD, LOGAN,
SEDGWICK AND PHILLIPS COUNTIES...

* Affected Area...Fire Weather Zones 238, 239, 242, 243, 244, 
  248, 250 and 251.

* Timing...Saturday from Noon to 7 PM.

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

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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.

&&

$$

219 
WWUS85 KBOU 261023
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
423 AM MDT Sat Sep 26 2020

Strong winds will develop in the foothills and South Park early 
this morning, then spread across the plains along the Wyoming 
border and southward in the afternoon. With dry air in place, relative
humidities will drop to as low as 10 percent in those same areas.
The hot, dry, and windy conditions will result in rapid growth of
existing fires and new fire starts so a Red Flag Warning was 
issued. 

COZ240-241-245-246-249-261830-
/O.EXB.KBOU.FW.W.0026.200926T1800Z-200927T0200Z/
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 East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-Washington County-
423 AM MDT Sat Sep 26 2020

...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS
EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE DENVER METRO,
PALMER DIVIDE, AND EAST-CENTRAL PLAINS...

The National Weather Service in Denver has issued a Red Flag
Warning FOR WIND AND LOW RELATIVE HUMIDITY, which is in effect
from noon today to 8 PM MDT this evening.

* Affected Area...Fire Weather Zones 240, 241, 245, 246 and 249.

* Timing... Saturday from Noon to 8 PM MDT.

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

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

* Impacts...Rapid growth of existing fires and new fire starts 
  will be possible due to the gusty winds and very low humidity.

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>216-239-261830-
/O.EXT.KBOU.FW.W.0026.200926T1500Z-200927T0200Z/
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-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
423 AM MDT Sat Sep 26 2020

...RED FLAG WARNING IN EFFECT FROM 9 AM THIS MORNING TO 8 PM MDT 
THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT 
RANGE FOOTHILLS, SOUTH PARK, AND EASTERN BOULDER AND JEFFERSON 
COUNTIES...

* Affected Area...Fire Weather Zones 214, 215, 216 and 239.

* Timing...Saturday from 9 AM to 8 PM.

* Winds...West 15 to 25 mph with gusts up to 50 mph.

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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.

&&

$$

COZ238-242>244-248-250-251-261830-
/O.EXT.KBOU.FW.W.0026.200926T1800Z-200927T0200Z/
Larimer County Below 6000 Feet/Northwest Weld County-
Northeast Weld County-Central and South Weld County-Morgan County-
Logan County-Sedgwick County-Phillips County-
423 AM MDT Sat Sep 26 2020

...RED FLAG WARNING NOW IN EFFECT FROM NOON TODAY TO 8 PM MDT
THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE LOWER
ELEVATIONS OF LARIMER COUNTY AS WELL AS WELD, LOGAN, MORGAN, SEDGWICK
AND PHILLIPS COUNTIES...

* Affected Area...Fire Weather Zones 238, 242, 243, 244, 248, 
  250 and 251.

* Timing...Saturday from Noon to 8 PM.

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

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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.

&&

$$

059 
WWUS85 KBOU 261526
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
926 AM MDT Sat Sep 26 2020

Strong winds in the foothills and South Park this morning, are 
expected to spread across the plains along the Wyoming border and 
southward in the afternoon. The unseasonably warm and dry 
conditions will produce relative humidities as low as 10 percent 
this afternoon, and result in rapid growth of existing fires and 
new fire starts.

COZ214>216-239-270200-
/O.CON.KBOU.FW.W.0026.000000T0000Z-200927T0200Z/
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-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
926 AM MDT Sat Sep 26 2020

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS,
SOUTH PARK, AND EASTERN BOULDER AND JEFFERSON COUNTIES...

* Affected Area...Fire Weather Zones 214, 215, 216 and 239.

* Timing...now through 8 PM.

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

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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.

&&

$$

COZ238-240>246-248>251-270200-
/O.CON.KBOU.FW.W.0026.200926T1800Z-200927T0200Z/
Larimer County Below 6000 Feet/Northwest Weld 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-Logan County-Washington County-Sedgwick County-
Phillips County-
926 AM MDT Sat Sep 26 2020

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE LOWER ELEVATIONS OF
LARIMER COUNTY AS WELL AS WELD, LOGAN, MORGAN, SEDGWICK AND
PHILLIPS COUNTIES...

* Affected Area...Fire Weather Zones 238, 240, 241, 242, 243, 
  244, 245, 246, 248, 249, 250 and 251.

* Timing...Noon to 8 PM.

* Winds...Northwest 10 to 25 mph with gusts up to 40 mph.

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

* Impacts...New fire starts will be possible due to the gusty 
  winds and very low humidity.

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.

&&

$$

261 
WWUS85 KBOU 270155
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
755 PM MDT Sat Sep 26 2020


COZ214>216-239-270300-
/O.EXP.KBOU.FW.W.0026.000000T0000Z-200927T0200Z/
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-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
755 PM MDT Sat Sep 26 2020

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR FRONT RANGE FOOTHILLS,
SOUTH PARK, EASTERN BOULDER AND JEFFERSON COUNTIES

Winds have decreased along with an increase in humidity.

$$

COZ238-240>246-248>251-270300-
/O.EXP.KBOU.FW.W.0026.000000T0000Z-200927T0200Z/
Larimer County Below 6000 Feet/Northwest Weld 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-Logan County-Washington County-Sedgwick County-
Phillips County-
755 PM MDT Sat Sep 26 2020

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR THE I-25 CORRIDOR AND ADJACENT 
PLAINS...

A cold front has moved across the area bringing higher humidity 
and cooler temperatures.

$$

Area Forecast Discussion
National Weather Service Denver/Boulder CO
936 AM MDT Fri Sep 25 2020

.UPDATE...
Issued at 917 AM MDT Fri Sep 25 2020

Only minor adjustments to the grids are expected this morning as
the forecast looks to be on track. Zonal flow aloft with downslope
conditions along the Front Range. This will result in dry
conditions with record high temperatures possible. Another 90
degree day today would increase the 2020 total to 76 for Denver.
There is some of the high cloudiness associated with a wave cloud
along the Front Range over the Denver area this morning. RAP
spatial cross-section indicates this should break up by midday.
With this in mind, we will stay the course and leave the forecast
as is.

&&

.SHORT TERM...(Today and tonight)
Issued at 345 AM MDT Fri Sep 25 2020

A flattened ridge across the U.S.-Mexico border southwest of
Colorado combined with a strong jet stream across the Pacific
northwest puts us in nearly zonal flow, and quite a bit of it for
this afternoon. Flow at 700 mb will increase to 30 kts out of the
west across the northern third of Colorado by this afternoon.
This will result in a breezy/windy day across the high country,
especially Jackson and Larimer Counties, but also a very warm and
dry day as downslope flow occurs east of the Park/Gore Range and
the Front Range. Suffice to say there is zero chance of any
precipitation through tonight across our area. In terms of
temperatures, 700 mb temps warm to +15, maybe +16 degC which would
normally support another 90 degree day across the I-25 urban
corridor and east across much of the plains. We still believe it
will hit 90 at DEN, but it's a little less certain given the
downslope flow does not look like it will extend east of I-25 at
the surface, maybe limiting temps by a degree or two. It's
splitting hairs and given how warm aloft it will be, it's still
likely to hit 90 and be day #76 of 2020 at KDEN, as well as many
locations across northeast Colorado. It will be in the 70s to near
80 in the mountain valleys, and west/east slope foothills. Fire
wx is a big concern, and that is covered in the fire weather
discussion below.

Tonight: continued clear skies and very dry air will lead to a
nice radiational cool down but still far above normal low
temperatures for late September. Expect 50s to near 60 for all but
the coolest low spots across the plains (i.e. Lincoln County and
the South Platte valley east of Greeley). Mountain valleys will
drop into the 30s.

.LONG TERM...(Saturday through Thursday)
Issued at 345 AM MDT Fri Sep 25 2020

A shortwave trough will move through the otherwise zonal flow on
Saturday ending the day over the Northern Plains. The wind speeds
within the jet stream that passes over the northern part of
Colorado will be rather strong with 500 mb winds reaching 70 knots
and 250 mb winds reaching 85 knots. At the surface, cyclogenesis
will extend from eastern South Dakota toward northeastern Colorado
with west to northwest winds on the west side of the
cyclogenesis. It won't take long for daytime heating to mix down
the stronger winds aloft toward the surface. Winds over the
higher terrain of Colorado will gust up to 40 mph while areas
along the Cheyenne Ridge will see gusts up to 35 mph. With
temperatures warming well above normal and dew points remaining
low, relative humidities will drop to the low teens across the
plains. The combination of low relative humidity and strong winds
will create critical fire danger across the northern tier of
counties across the plains. Therefore, a Fire Weather Watch was
issued for those locations. There does remain some uncertainty
with regards to the possible development of a mountain wave cloud.
It appears likely that an extensive mountain wave cloud will
cover a good portion of the northeastern plains which would limit
surface heating and keep relative humidities slightly higher.
Consequently, no fire weather highlights were issued elsewhere. As
Saturday nears, there may be a need to expend the coverage of the
Fire Weather Watch/Red Flag Warning area. Due to the expected
mountain wave cloud, Denver is expected to fall just short of the
record high of 90 although it is well within reach. Otherwise,
there will be dry weather.

A secondary shortwave trough will move towards Colorado from the
British Colombia region on Sunday. Models have shifted their
forecast towards a deeper trough and stronger cold front with the
ECMWF being the first to latch onto this solution. PVA ahead of
this shortwave will create mid to upper level QG ascent while
strong frontogenesis at the surface will lead to low level QG
ascent. The limiting factor for the development of precipitation
will be the relatively dry air associated with this system.
Despite this dry air, light precipitation is expected to fall
across our forecast area behind the front. Upslope flow along the
western slopes and the Palmer Divide will aid in producing higher
precipitation amounts there. Considering the cold air aloft with
this system, there will be some light snow in the mountains but
accumulation should be less than an inch. High temperatures will
be heavily dependent on the timing of the front. If the front
moves across the forecast area during the morning, highs may
struggle to get much above 60 across the plains. If the front is
slower, highs may reach the 70s briefly before dropping behind the
front.

A highly amplified pattern will develop on Monday and last through
much of the work week. On Monday, mid to upper level winds will be
due north over Colorado between a trough over the eastern US and a
ridge over the western US. Colorado will spend much of next week
under the influence of the ridge rather than the trough resulting
in subsident flow and dry weather. At the surface, persistent
northwest to northerly flow will usher in waves of cooler air
with temperatures near to slightly below normal for much of the
work week. No hazardous weather is expected considering the lack
of precipitation and increased relative humidities.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 917 AM MDT Fri Sep 25 2020

VFR through Saturday. Westerly flow aloft should keep most of the
smoke north of the terminals. Winds at the KDEN and KAPA terminals
should remain east/southeast, around 10 kts. The exception could
be KBJC where west winds off the foothills could gust over 20 kts
this afternoon. Not at all confident the westerly push will reach
KDEN. Winds will return to SSW winds around 10-12 kts after 9 PM
tonight at DEN, weaker at KAPA and KBJC. Saturday afternoon
should be windier at the terminals with WNW winds 15-20 kts with
gusts possibly exceeding 25 kts.

&&

.FIRE WEATHER...
Issued at 749 AM MDT Fri Sep 25 2020

Westerly flow will increase today, the result of deep boundary
layer mixing and a much stronger pressure gradient with a jet
stream across the northern Rockies. RH should bottom out between
13-16 percent across the high country and foothills, even lower
across the plains. Winds will be much lighter east of I-25, thus
there are no fire wx highlights in effect for Friday. Over the
higher elevations, winds may gust to 40 mph during the afternoon
hours, thus we have an RFW in effect through 8 PM for just about
all of the high country. RH recovery tonight will be poor
especially across the eastern slopes of the Front Range and the
ridges across Jackson and Grand Counties.

A passing upper level disturbance will create strong winds on
Saturday. Winds over the higher terrain of Colorado will gust up
to 40 mph while areas along the Cheyenne Ridge will see gusts up
to 35 mph. With temperatures warming well above normal and dew
points remaining low, relative humidities will drop to the low
teens across the plains. The combination of low relative humidity
and strong winds will create critical fire danger across the
northern tier of counties across the plains. Therefore, a Fire
Weather Watch was issued for those locations. In other areas, like
South Park and the southern Front Range foothills, conditions
will be close to reaching red flag criteria so there may be a need
to expend the coverage of the Fire Weather Watch/Red Flag Warning
area.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Saturday afternoon through Saturday
evening for COZ238-242-248-250-251.

Red Flag Warning until 8 PM MDT this evening for COZ211>218.

&&

UPDATE...Cooper
SHORT TERM...Schlatter
LONG TERM...Danielson
AVIATION...Cooper
FIRE WEATHER...Schlatter/Danielson

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1038 AM MDT Fri Sep 25 2020

COZ030>051-261645-
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-
1038 AM MDT Fri Sep 25 2020

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

.DAY ONE...Today and Tonight

Very warm and dry conditions, combined with gusty west winds,
will lead to critical fire danger across the mountains, high
mountain valleys and foothills this afternoon. Winds could gust
to 40 mph, and RH should drop below 15 percent. Conditions are
favorable for rapid fire growth this afternoon across north
central Colorado.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Warm and dry conditions are expected to continue Saturday,
leading to areas of critical fire danger. The greatest threat
will be across the northern plains where wind gusts may reach up
to 35 mph. Another area of concern will the South Park and the
southern foothills where gusts will be between 25 and 30 mph.

Cooling temperatures are expected Sunday as a strong cold front
pushes south across the area, which will help ease fire danger
levels. Light rain is expected across much of the area Sunday
afternoon and evening with light snow possible in the mountains.
Snow levels will be lowering to near 8000 ft by late afternoon north
of I70, continuing south through the evening over areas south of
I70. Snowfall accumulations will be less than one inch and travel
impacts should be very minimal. No hazardous weather is expected
Monday through Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.