Alert archive / Oregon / Red Flag Warnings in 2021

Red Flag Warning 11, NWS Portland, OR

August 11, 2021

NWS Portland, OR issued this red flag warning at Aug 11, 2021, 12:53 PM PDT. It took effect at Aug 12, 2021, 11:00 AM PDT. It was in force for 34 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
Aug 11, 2021, 12:53 PM PDT (19:53 UTC)
In effect from
Aug 12, 2021, 11:00 AM PDT
Expired
Aug 13, 2021, 9:02 PM PDT
In force
34 hr
Issued by
NWS Portland, OR

The text

As transmitted.

324 
WWUS86 KPQR 111953
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
1253 PM PDT Wed Aug 11 2021

...VERY UNSTABLE CONDITIONS EXPECTED THURSDAY AND FRIDAY...

.Conditions above 2500 feet MSL will become significantly unstable
Thursday across the Central Cascades and the Central Coast Range.
The deep instability expands northward for Friday to include the
North Coast Range and Cascades. Hot temperatures and very low
humidity will contribute to burning conditions. Additionally, weak
low pressure will move north to provide additional mid-level
instability for deeper mixing potential. Finally, additional mid-
level moisture on Friday may result in isolated thunderstorms over
the Central Cascades.

ORZ603-606-608-120400-
/O.NEW.KPQR.FW.W.0011.210812T1800Z-210814T0500Z/
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-Willamette National Forest-
1253 PM PDT Wed Aug 11 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM THURSDAY TO 10 PM PDT
FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 603, 606, AND 608...

The National Weather Service in Portland has issued a Red Flag
Warning for significantly unstable conditions, which is in effect
from 11 AM Thursday to 10 PM PDT Friday.

* Affected Area...In Oregon above 2500 feet...Fire Weather Zone 
  603 East Slopes of the Central Oregon Coast Range...Fire Weather
  Zone 606 Central Oregon Cascade Foothills and Fire Weather Zone
  608 Willamette National Forest.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any
  new or existing fires. Extreme fire behavior is possible under
  potential plume dominated behavior. Pyro-cumulus and pyro-
  cumulonimbus activity is possible. Outdoor burning is not 
  recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5,
  however, the deep surface mixing and instability is resulting in
  stability component values of 3. Additionally for Friday and
  over the Cascades, mid-level moisture may produce isolated
  thunderstorms which produce very little surface rain and gusty
  outflow winds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ607-WAZ660-663-120400-
/O.NEW.KPQR.FW.W.0011.210813T1800Z-210814T0500Z/
Mt. Hood National Forest West of Cascade Crest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
1253 PM PDT Wed Aug 11 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM TO 10 PM PDT FRIDAY FOR
SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET ACROSS FIRE 
WEATHER ZONES 607,660, AND 663...

The National Weather Service in Portland has issued a Red Flag
Warning for significantly unstable conditions, which is in effect
from 11 AM to 10 PM PDT Friday.

* Affected Area...In Oregon above 2500 feet...Fire Weather Zone 
  607 Mt. Hood National Forest West of Cascade Crest. In 
  Washington...Fire Weather Zone 660 Extreme South Washington 
  Cascades and Foothills and Fire Weather Zone 663 Eastern Gifford
  Pinchot National Forest Mt Adams Ranger District.

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

* Temperatures...85-100 degrees.

* Impacts...Conditions may be favorable for rapid spread on any
  new or existing fires. Extreme fire behavior is possible under
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5,
  however, the deep surface mixing and instability is resulting in
  stability component values of 3. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

For more information visit: http://weather.gov/portland
6 follow-up statements
369 
WWUS86 KPQR 120315
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
815 PM PDT Wed Aug 11 2021

...VERY UNSTABLE CONDITIONS EXPECTED THURSDAY AND FRIDAY...

.Conditions above 2500 feet MSL will become significantly
unstable Thursday across the Central Cascades and the Central
Coast Range. The deep instability expands northward for Friday to
include the North Coast Range and Cascades. Hot temperatures and
very low humidity will contribute to burning conditions.
Additionally, weak low pressure will move north to provide
additional mid-level instability for deeper mixing potential.
Finally, additional mid-level moisture on Friday may result in 
isolated thunderstorms over the Central Cascades.

ORZ603-606-608-121200-
/O.CON.KPQR.FW.W.0011.210812T1800Z-210814T0500Z/
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-Willamette National Forest-
815 PM PDT Wed Aug 11 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THURSDAY TO
10 PM PDT FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE
2500 FEET ACROSS FIRE WEATHER ZONES 603, 606, AND 608...

* Affected Area...In Oregon...Fire Weather Zone 603 East Slopes 
  of the Central Oregon Coast Range...Fire Weather Zone 606 
  Central Oregon Cascade Foothills and Fire Weather Zone 608 
  Willamette National Forest.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus and pyro- 
  cumulonimbus activity is possible. Outdoor burning is not 
  recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3. Additionally for Friday 
  and over the Cascades, mid-level moisture may produce isolated 
  thunderstorms which produce very little surface rain and gusty 
  outflow winds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ607-WAZ660-663-121200-
/O.CON.KPQR.FW.W.0011.210813T1800Z-210814T0500Z/
Mt. Hood National Forest West of Cascade Crest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
815 PM PDT Wed Aug 11 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 10 PM PDT
FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 607, 660, AND 663...

* Affected Area...In Oregon...Fire Weather Zone 607 Mt. Hood 
  National Forest West of Cascade Crest. In Washington...Fire 
  Weather Zone 660 Extreme South Washington Cascades and 
  Foothills and Fire Weather Zone 663 Eastern Gifford Pinchot 
  National Forest Mt Adams Ranger District.

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

* Temperatures...85-100 degrees.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

For more information visit: http://weather.gov/portland
856 
WWUS86 KPQR 121135
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
435 AM PDT Thu Aug 12 2021

...VERY UNSTABLE CONDITIONS EXPECTED THURSDAY AND FRIDAY...

.Conditions above 2500 feet MSL will become significantly
unstable Thursday across the Central Cascades and the Central
Coast Range. The deep instability expands northward for Friday to
include the North Coast Range and Cascades. Hot temperatures and
very low humidity will contribute to burning conditions.
Additionally, weak low pressure will move north to provide
additional mid-level instability for deeper mixing potential.
Finally, additional mid-level moisture on Friday may result in
isolated thunderstorms over the Central Cascades.

ORZ603-606-608-130000-
/O.CON.KPQR.FW.W.0011.210812T1800Z-210814T0500Z/
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-Willamette National Forest-
435 AM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
10 PM PDT FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE
2500 FEET ACROSS FIRE WEATHER ZONES 603, 606, AND 608...

* Affected Area...In Oregon...Fire Weather Zone 603 East Slopes 
  of the Central Oregon Coast Range...Fire Weather Zone 606 
  Central Oregon Cascade Foothills and Fire Weather Zone 608 
  Willamette National Forest.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus and pyro- 
  cumulonimbus activity is possible. Outdoor burning is not 
  recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3. Additionally for Friday 
  and over the Cascades, mid-level moisture may produce isolated 
  thunderstorms which produce very little surface rain and gusty 
  outflow winds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ607-WAZ660-663-130000-
/O.CON.KPQR.FW.W.0011.210813T1800Z-210814T0500Z/
Mt. Hood National Forest West of Cascade Crest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
435 AM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 10 PM PDT
FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 607, 660, AND 663...

* Affected Area...In Oregon...Fire Weather Zone 607 Mt. Hood 
  National Forest West of Cascade Crest. In Washington...Fire 
  Weather Zone 660 Extreme South Washington Cascades and 
  Foothills and Fire Weather Zone 663 Eastern Gifford Pinchot 
  National Forest Mt Adams Ranger District.

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

* Temperatures...85-100 degrees.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

For more information visit: http://weather.gov/portland
637 
WWUS86 KPQR 121556
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
856 AM PDT Thu Aug 12 2021

...VERY UNSTABLE CONDITIONS EXPECTED TODAY AND FRIDAY...

.Conditions above 2500 feet MSL will become significantly
unstable today across the Central Cascades and the Central Coast 
Range. The deep instability expands northward on Friday to 
include the North Coast Range and Cascades. Hot temperatures and 
very low humidity will contribute to burning conditions. 
Additionally, weak low pressure will move north to provide 
additional mid-level instability for deeper mixing potential. 
Finally, additional mid-level moisture on Friday may result in 
isolated thunderstorms over the Central Cascades.

ORZ602-130000-
/O.EXA.KPQR.FW.W.0011.210813T1800Z-210814T0500Z/
North Oregon Coast Range-
856 AM PDT Thu Aug 12 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM TO 10 PM PDT FRIDAY FOR
SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET FOR FIRE 
WEATHER ZONE 602...

The National Weather Service in Portland has issued a Red Flag
Warning for significantly unstable conditions, which is in effect
from 11 AM to 10 PM PDT Friday.

* Affected Area...In Oregon Above 2500 feet...Fire Weather Zone 
  602 North Oregon Coast Range.

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

* Temperatures...85-100 degrees.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ603-606-608-130000-
/O.CON.KPQR.FW.W.0011.210812T1800Z-210814T0500Z/
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-Willamette National Forest-
856 AM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT FRIDAY FOR
SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET ACROSS FIRE
WEATHER ZONES 603, 606, AND 608...

* Affected Area...In Oregon above 2500 feet...Fire Weather Zone 
  603 East Slopes of the Central Oregon Coast Range...Fire Weather
  Zone 606 Central Oregon Cascade Foothills and Fire Weather Zone
  608 Willamette National Forest.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus and pyro- 
  cumulonimbus activity is possible. Outdoor burning is not 
  recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3. Additionally for Friday 
  and over the Cascades, mid-level moisture may produce isolated 
  thunderstorms which produce very little surface rain and gusty 
  outflow winds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ607-WAZ660-663-130000-
/O.CON.KPQR.FW.W.0011.210813T1800Z-210814T0500Z/
Mt. Hood National Forest West of Cascade Crest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
856 AM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 10 PM PDT
FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 607, 660, AND 663...

* Affected Area...In Oregon Above 2500 feet...Fire Weather Zone
  607 Mt. Hood National Forest West of Cascade Crest. In
  Washington Above 2500 feet...Fire Weather Zone 660 Extreme 
  South Washington Cascades and Foothills and Fire Weather Zone 
  663 Eastern Gifford Pinchot National Forest Mt Adams Ranger 
  District.

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

* Temperatures...85-100 degrees.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

For more information visit: http://weather.gov/portland
839 
WWUS86 KPQR 122253
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
353 PM PDT Thu Aug 12 2021

...VERY UNSTABLE CONDITIONS EXPECTED TODAY AND FRIDAY...

.Conditions above 2500 feet MSL will become significantly
unstable today across the Central Cascades and the Central Coast
Range. The deep instability expands northward on Friday to
include the North Coast Range and Cascades. Hot temperatures and
very low humidity will contribute to burning conditions.
Additionally, weak low pressure will move north Friday to provide
additional mid-level instability for deeper mixing potential.
Finally, additional mid-level moisture on Friday may result in
isolated thunderstorms over the Central Cascades.

ORZ603-606-608-140000-
/O.CON.KPQR.FW.W.0011.000000T0000Z-210814T0500Z/
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-Willamette National Forest-
353 PM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT FRIDAY FOR
SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET ACROSS FIRE
WEATHER ZONES 603, 606, AND 608...

* Affected Area...In Oregon above 2500 feet...Fire Weather Zone 
  603 East Slopes of the Central Oregon Coast Range...Fire Weather
  Zone 606 Central Oregon Cascade Foothills and Fire Weather Zone
  608 Willamette National Forest.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus and pyro- 
  cumulonimbus activity is possible. Outdoor burning is not 
  recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3. Additionally for Friday 
  and over the Cascades, mid-level moisture may produce isolated 
  thunderstorms which produce very little surface rain and gusty 
  outflow winds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ602-607-WAZ660-663-140000-
/O.CON.KPQR.FW.W.0011.210813T1800Z-210814T0500Z/
North Oregon Coast Range-
Mt. Hood National Forest West of Cascade Crest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
353 PM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 10 PM PDT
FRIDAY FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 607, 660, AND 663...

* Affected Area...In Oregon above 2500 feet...Fire Weather Zone
  602 North Oregon Coast Range and Fire Weather Zone 607 Mt. Hood
  National Forest West of Cascade Crest. In Washington above 2500
  feet...Fire Weather Zone 660 Extreme South Washington Cascades 
  and Foothills and Fire Weather Zone 663 Eastern Gifford Pinchot 
  National Forest Mt Adams Ranger District.

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

* Temperatures...85-100 degrees.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

For more information visit: http://weather.gov/portland
610 
WWUS86 KPQR 132232
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
332 PM PDT Fri Aug 13 2021

ORZ603-606-608-140500-
/O.CON.KPQR.FW.W.0011.000000T0000Z-210814T0500Z/
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-Willamette National Forest-
332 PM PDT Fri Aug 13 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT THIS
EVENING FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 603, 606, AND 608...

* Affected Area...In Oregon...Fire Weather Zone 603 East Slopes 
  of the Central Oregon Coast Range...Fire Weather Zone 606 
  Central Oregon Cascade Foothills and Fire Weather Zone 608 
  Willamette National Forest.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus and pyro- 
  cumulonimbus activity is possible. Outdoor burning is not 
  recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5,
  however, the deep surface mixing and instability is resulting in
  stability component values of 3. Additionally for this evening
  over the Cascades, mid-level moisture may produce isolated 
  thunderstorms which produce very little surface rain and gusty 
  outflow winds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

ORZ602-607-WAZ660-663-140500-
/O.CON.KPQR.FW.W.0011.000000T0000Z-210814T0500Z/
North Oregon Coast Range-
Mt. Hood National Forest West of Cascade Crest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
332 PM PDT Fri Aug 13 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT THIS
EVENING FOR SIGNIFICANTLY UNSTABLE CONDITIONS ABOVE 2500 FEET
ACROSS FIRE WEATHER ZONES 607, 660, AND 663...

* Affected Area...In Oregon...Fire Weather Zone 602 North Oregon 
  Coast Range and Fire Weather Zone 607 Mt. Hood National Forest 
  West of Cascade Crest. In Washington...Fire Weather Zone 660 
  Extreme South Washington Cascades and Foothills and Fire 
  Weather Zone 663 Eastern Gifford Pinchot National Forest Mt 
  Adams Ranger District.

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

* Temperatures...85-100 degrees.

* Instability...Deep surface mixing with heights 7000-12000 feet 
  above ground level.

* Impacts...Conditions may be favorable for rapid spread on any 
  new or existing fires. Extreme fire behavior is possible under 
  potential plume dominated behavior. Pyro-cumulus activity is 
  possible. Outdoor burning is not recommended.

* ADDITIONAL DETAILS...High Level Haines values will be 4 and 5, 
  however, the deep surface mixing and instability is resulting 
  in stability component values of 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of the
above conditions can contribute to extreme fire behavior.

&&

$$

For more information visit: http://weather.gov/portland
619 
WWUS86 KPQR 140402
RFWPQR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Portland OR
902 PM PDT Fri Aug 13 2021


ORZ602-603-606>608-WAZ660-663-140515-
/O.CAN.KPQR.FW.W.0011.000000T0000Z-210814T0500Z/
North Oregon Coast Range-
East Slopes of the Central Oregon Coast Range-
Central Oregon Cascade Foothills-
Mt. Hood National Forest West of Cascade Crest-
Willamette National Forest-
Extreme South Washington Cascades and Foothills-
Eastern Gifford Pinchot National Forest Mt Adams Ranger District-
902 PM PDT Fri Aug 13 2021

...RED FLAG WARNING IS CANCELLED FOR FIRE WEATHER ZONES 
602...603...606...607...608...660 AND 663...

The National Weather Service in Portland has cancelled the Red
Flag Warning. The threat for rapid fire spread on existing fires
has diminished this evening. 



$$

For more information visit: http://weather.gov/portland

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 Portland, OR wrote its last area forecast discussion before this red flag warning went out at Aug 11, 11:17 AM PDT, 1 hour 36 minutes earlier.

Area forecast discussion, Aug 11, 11:17 AM PDT, 1 hour 36 minutes before
Area Forecast Discussion
National Weather Service Portland OR
1117 AM PDT Wed Aug 11 2021

Updated aviation and marine sections...

.SYNOPSIS...High pressure will continue across the region through
Friday leading to hot and dry weather. An excessive heat warning is
in effect from noon Wednesday to Saturday evening. The upper ridge
will shift east this weekend with a slight cooling trend starting
Saturday and continuing into early next week.

&&

.SHORT TERM...TODAY THROUGH FRIDAY...Water vapor satellite imagery
early Wednesday morning shows an upper level ridge extending across
the northeast Pacific, the Gulf of Alaska and into the Pacific
Northwest. The upper high currently centered southwest of Vancouver
Island will expand across much of the PNW today, while the upper
ridge gradually shifts eastward during the next few days. This
weather pattern will bring a continuation of dry weather and
increasing temperatures as the atmosphere continues to be compressed
and warmed near the surface.

Temperatures will rapidly increase during the day today into the
upper 90s to near 100F, at least 15 degrees above normal for mid
August. Model forecast soundings indicate 850 mb temperatures of
around 20C this morning will warm to around 25C by Thursday, which
if mixed to the surface, would yield a temperature of 104F. This is
certainly possible Thursday as the upper ridge axis will be
positioned along the coast extending northward into British
Columbia. Record high temperatures at PDX during this time of year
have been recorded in the 102-107F range. But there is still a
substantial amount of uncertainty that temperatures will reach this
high, as indicated by the NBM. Under clear skies much of the
Willamette Valley and southwest Washington will more likely than not
reach the 100 degree mark. The latest HRRR smoke model shows
increasing chances of high level haze over the area Thursday which
could limit the amount of surface warming. It is interesting to note
the NBM has a 10% chance for temperatures reaching 105F at PDX
(worst case scenario), while also showing a 10% chance of
temperatures only reaching 90F ("best" case scenario). Will continue
with most likely scenario of inland temperatures 15 to 20 degrees
above normal on Thursday.

Coastal locations may see a brief warm up, especially the northern
Oregon and south Washington coast, to near 80F. But the central
Oregon coast is expected to remain near normal under the influence
of the marine airmass.

Friday also has the possibility of being somewhat interesting as the
upper ridge begins to shift east. There are still subtle differences
between deterministic models but generally show a weak upper low
lifting north off the northern California coast. This would allow
increasing southerly flow aloft, and depending on the amount of
midlevel moisture available, could initiate some convection across
parts of southern and central OR, including the central OR Cascades
in Lane County. 850 mb temperatures should still be around 25C
Friday, so similar temperatures may be possible, but if cloud
coverage increases, temps would likely be slightly lower. Models
also indicate possible southwest marine push increasing along the
central coast Friday morning with some influence felt into the
southern Willamette Valley. Lowered daytime high temperatures back
into the mid to upper 90s here, while keeping temps from Salem
northward around 100-102F. Overnight temperatures may not provide
much relief, as temperatures generally remain above 70F. More rural
locations, though are more likely to fall into the mid 60s.

The Excessive Heat Warning will be in effect beginning noon today
covering the majority of the CWA, excluding the coast. With the
widespread heat expected, there is an enhanced risk to sensitive
groups. Drink lots of water, check on neighbors, friends and family
often, and locate to a cool space during the peak heating time
frames. Refer to local emergency management agencies to find cooling
sites near you.  /DDH

&&

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...By Saturday, the
ridge will shift further inland and more of a true onshore flow
pattern will take over. Temperatures will begin to slowly cool
starting Saturday afternoon, although still expecting 90F+ degree
temperatures inland. All coastal areas should return to a more
normal temperature pattern. By Sunday models show a low dropping
down over the southern Alaska Panhandle. Some indication of light
rain possible by ensembles and the NBM so have included a slight
chance POP for Sunday night. WPC 500 mb cluster analysis shows
general broad troughing over the Pacific Northwest Monday. This
indicates temperatures should continue to cool with more mild and
seasonable conditions expected by Monday.

&&

.AVIATION...High pressure over the region will result in
predominantly VFR conditions areawide through 18z Thursday. The
main exception to this will be along the coast where a southerly
wind reversal and fog and low clouds will spread northward up the
coast tonight. This will likely result in a mix of IFR and LIFR
conditions pushing into KONP between 06-12z Thursday. There is a
chance it could push all the way northward and impact KAST between
12-18z Thursday, but nearly all of the model guidance
available suggests it will fall short.

Smoke from the wildfires burning in the Oregon Cascades will
continue to primarily impact eastern Lane, Linn and Marion
Counties over the next 24 hours. The latest HRRR smoke model
does suggest some smoke from BC/WA wildfires will drop
southwestward through the Columbia River Basin and begin to
impact the Columbia River Gorge and northern Willamette Valley
shortly after 18z Thursday. Do not expect this to bring IFR
restrictions at this point, but would expect the skies to become
noticeably more hazy with surface visibilities perhaps dropping
into the 5-9 mile range. Confidence is not terribly high that
visibilities will drop even that low, though, considering the smoke
field does not appear all that impressive on satellite imagery in
the source region of eastern Washington and southern British
Columbia.

For detailed regional Pac NW aviation weather information, go
online to: https://weather.gov/zse

KPDX AND APPROACHES...High pressure aloft will result in light
winds and VFR conditions through 18z Thursday. Some smoke from
BC/WA wildfires will begin to spread westward through the
Columbia River Gorge shortly after 18z Thursday and may result in
surface visibilities falling into the 5-9 mile range. Confidence
is relatively low that visibilities will drop even into those
values considering the smoke field does not appear all that
impressive on satellite imagery in the source region. /Neuman

&&

.MARINE...High pressure over the northeast Pacific and a thermally
induced lower pressure over western Oregon will result in breezy
northerly winds today. There could be a few isolated spots with
gusts to 21 kt in the afternoon, but do not expect wind gusts this
strong to be widespread enough to necessitate a Small Craft
Advisory.

A southerly wind reversal will move northward up the coast
bringing areas of fog and a brief burst of 10 to 20 kt southerly
wind gusts tonight into Thursday. Southerly winds should then more
or less persist through the weekend, but remain well below Small
Craft Advisory thresholds of 21-25 kt. Expect seas to climb into the
7 to 9 ft range over the next 24 hours as an incoming northwesterly
swell pushes into the waters. Seas should gradually decrease
thereafter and drop below 5 ft for the weekend. /Neuman

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Excessive Heat Warning until 10 PM PDT Saturday for Cascade
     Foothills in Lane County-Cascades in Lane County-Central
     Coast Range of Western Oregon-Central Columbia River Gorge-
     Central Willamette Valley-Coast Range of Northwest Oregon-
     Greater Portland Metro Area-Lower Columbia-Northern Oregon
     Cascade Foothills-Northern Oregon Cascades-South
     Willamette Valley-Upper Hood River Valley-Western Columbia
     River Gorge.

WA...Excessive Heat Warning until 10 PM PDT Saturday for Central
     Columbia River Gorge-Greater Vancouver Area-I-5 Corridor
     in Cowlitz County-South Washington Cascade Foothills-South
     Washington Cascades-Western Columbia River Gorge.

PZ...Small Craft Advisory until noon PDT today for Waters from
     Cascade Head to Florence OR from 10 to 60 NM.

&&

The office that day

Everything else NWS Portland, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 2:37 PM PDTSmall Craft AdvisoryPQR19 hr

Nearby

Red Flag Warnings in Oregon, 2021Red Flag Warnings in Washington, 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.