Alert archive / Washington / Red Flag Warnings in 2021

Red Flag Warning 2, NWS Seattle, WA

August 11, 20217 counties in Washington

NWS Seattle, WA issued this red flag warning at Aug 11, 2021, 1:52 PM PDT for 7 counties in Washington. It took effect at Aug 12, 2021, 10:00 AM PDT. It was in force for 36 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, 1:52 PM PDT (20:52 UTC)
In effect from
Aug 12, 2021, 10:00 AM PDT
Expired
Aug 13, 2021, 10:00 PM PDT
In force
36 hr
Issued by
NWS Seattle, WA

Counties King County, WA, Lewis County, WA, Pierce County, WA, Skagit County, WA, Skamania County, WA, Snohomish County, WA, Whatcom County, WA

The radar

The Seattle radar (KATX), 87 km from the middle of the area, began a volume at 20:54 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

Quillayute State, WA (KUIL), launched 12:00Z, 8.9 hours before the alert went out and 197 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, Quillayute State, WA at 12:00Z on 2021-08-11Temperature 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 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Quillayute State, WA at 12:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.1939Sfc1 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
1766 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

898 
WWUS86 KSEW 112052
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
152 PM PDT Wed Aug 11 2021

WAZ658-659-120500-
/O.UPG.KSEW.FW.A.0001.210812T1800Z-210813T0600Z/
/O.NEW.KSEW.FW.W.0002.210812T1800Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
152 PM PDT Wed Aug 11 2021

...RED FLAG WARNING IN EFFECT FROM 11 AM THURSDAY TO 10 PM PDT
FRIDAY FOR HOT, DRY AND UNSTABLE CONDITIONS FOR FIRE WEATHER
ZONES 658 AND 659...

The National Weather Service in Seattle has upgraded the Fire
Weather Watch to a Red Flag Warning for hot, dry and unstable 
conditions, which is in effect from 11 AM Thursday to 10 PM PDT 
Friday.

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 20 percent during the daytime 
  hours. Modest overnight recoveries are possible below around
  2500 feet which will provide a brief break in the period of
  However, the higher slopes will experience very poor recovery.

* TEMPERATURES...In the upper 70s to lower 80s.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm temperatures 
  can contribute to active fire behavior. In western Washington, 
  significant growth on existing fires takes place under such 
  conditions. If a fire were to begin, air quality may diminish 
  in the surrounding area.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
8 follow-up statements
543 
WWUS86 KSEW 112241
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
341 PM PDT Wed Aug 11 2021

WAZ658-659-120645-
/O.CON.KSEW.FW.W.0002.210812T1800Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
341 PM PDT Wed Aug 11 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THURSDAY TO
10 PM PDT FRIDAY FOR HOT, DRY AND UNSTABLE CONDITIONS FOR FIRE
WEATHER ZONES 658 AND 659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 20 percent during the daytime
  hours. Modest overnight recoveries are possible below around
  2500 feet which will provide a brief break in the period of
  concern. However, the higher slopes will experience very poor
  recovery.

* TEMPERATURES...In the upper 70s to lower 80s.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
620 
WWUS86 KSEW 120548
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
1048 PM PDT Wed Aug 11 2021

WAZ658-659-121400-
/O.CON.KSEW.FW.W.0002.210812T1800Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
1048 PM PDT Wed Aug 11 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THURSDAY TO
10 PM PDT FRIDAY FOR HOT, DRY AND UNSTABLE CONDITIONS FOR FIRE
WEATHER ZONES 658 AND 659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 22 percent.

* TEMPERATURES...In the upper 70s.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
184 
WWUS86 KSEW 121129
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
429 AM PDT Thu Aug 12 2021

WAZ658-659-130000-
/O.CON.KSEW.FW.W.0002.210812T1800Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
429 AM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
10 PM PDT FRIDAY FOR HOT, DRY AND UNSTABLE CONDITIONS FOR FIRE
WEATHER ZONES 658 AND 659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 20 percent during the daytime
  hours. Modest overnight recoveries are possible below around
  2500 feet which will provide a brief break in the period of
  concern. However, the higher slopes will experience very poor
  recovery.

* TEMPERATURES...In the upper 70s to lower 80s.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
309 
WWUS86 KSEW 121700
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
1000 AM PDT Thu Aug 12 2021

WAZ656-130100-
/O.EXB.KSEW.FW.W.0002.210812T1700Z-210814T0200Z/
Northeast Puget Sound Lowlands Generally Below 1500 Feet-
1000 AM PDT Thu Aug 12 2021

...RED FLAG WARNING IN EFFECT UNTIL 7 PM PDT FRIDAY FOR HOT DRY
AND WINDY CONDITIONS FOR FIRE WEATHER ZONE 656...

The National Weather Service in Seattle has issued a Red Flag
Warning for hot dry and windy conditions which is in effect until
7 PM PDT Friday.

* AFFECTED AREA...Fire Weather Zone 656 Northeast Puget Sound 
  Lowlands Generally Below 1500 Feet. 

* WINDS...Northeast 10 to 20 mph with gusts to 30 mph in the
  Lynden and Sumas area due to northeast winds coming down the
  Fraser. 

* RELATIVE HUMIDITY...As low as 20 percent.

* TEMPERATURES...Highs 90 to 95.

* TIMING...Through mid afternoon then easing.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$

WAZ658-659-130100-
/O.CON.KSEW.FW.W.0002.210812T1800Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
1000 AM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT FRIDAY FOR
HOT, DRY AND UNSTABLE CONDITIONS FOR FIRE WEATHER ZONES 658 AND 
659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 20 percent during the daytime
  hours. Modest overnight recoveries are possible below around
  2500 feet which will provide a brief break in the period of
  concern. However, the higher slopes will experience very poor
  recovery.

* TEMPERATURES...In the upper 70s and 80s.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
350 
WWUS86 KSEW 122129
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
229 PM PDT Thu Aug 12 2021

WAZ658-659-130530-
/O.CON.KSEW.FW.W.0002.000000T0000Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
229 PM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT FRIDAY FOR
HOT, DRY AND UNSTABLE CONDITIONS FOR FIRE WEATHER ZONES 658 AND
659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 25 percent.

* TEMPERATURES...In the upper 70s and 80s except 90s lowest
  elevations.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$

WAZ656-130530-
/O.CON.KSEW.FW.W.0002.000000T0000Z-210814T0200Z/
Northeast Puget Sound Lowlands Generally Below 1500 Feet-
229 PM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM PDT FRIDAY FOR
HOT DRY AND WINDY CONDITIONS FOR FIRE WEATHER ZONE 656...

* AFFECTED AREA...Fire Weather Zone 656 Northeast Puget Sound 
  Lowlands Generally Below 1500 Feet.

* WINDS...Northeast 10 to 20 mph becomign northwest 5 to 10 mph.

* RELATIVE HUMIDITY...As low as 25 percent.

* TEMPERATURES...Highs in the mid and upper 90s away from the
  water this afternoon.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
784 
WWUS86 KSEW 130332
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
832 PM PDT Thu Aug 12 2021

WAZ658-659-131230-
/O.CON.KSEW.FW.W.0002.000000T0000Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
832 PM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT FRIDAY FOR
HOT, DRY AND VERY UNSTABLE CONDITIONS FOR FIRE WEATHER ZONES 658 
AND 659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 20 percent. Poor recovery is
  expected tonight above around 2,500 feet, while lower elevations
  may experiences moderate recoveries.

* TEMPERATURES...In the upper 70s to 80s

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$

WAZ656-131230-
/O.CON.KSEW.FW.W.0002.000000T0000Z-210814T0200Z/
Northeast Puget Sound Lowlands Generally Below 1500 Feet-
832 PM PDT Thu Aug 12 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM PDT FRIDAY FOR
HOT DRY AND WINDY CONDITIONS FOR FIRE WEATHER ZONE 656...

* AFFECTED AREA...Fire Weather Zone 656 Northeast Puget Sound 
  Lowlands Generally Below 1500 Feet.

* WINDS...Northeast 10 to 20 mph, easing Friday and becoming 
  northwest late Friday afternoon.

* RELATIVE HUMIDITY...Daytime RHs as low 20 to 25 percent, though
  poor to moderate recoveries expected overnight.

* TEMPERATURES...Highs in the upper 80s to 90s away from the water.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
963 
WWUS86 KSEW 131033
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
333 AM PDT Fri Aug 13 2021

WAZ656-131145-
/O.CAN.KSEW.FW.W.0002.000000T0000Z-210814T0200Z/
Northeast Puget Sound Lowlands Generally Below 1500 Feet-
333 AM PDT Fri Aug 13 2021

...RED FLAG WARNING IS CANCELLED FOR HOT DRY AND WINDY CONDITIONS
FOR FIRE WEATHER ZONE 656...

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

While isolated or short instances may occur during the day today,
winds and RH values are expected to generally remain outside of 
critical thresholds. As such, the red flag warning has been
cancelled.

$$

WAZ658-659-131845-
/O.CON.KSEW.FW.W.0002.000000T0000Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
333 AM PDT Fri Aug 13 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT THIS
EVENING FOR HOT, DRY AND VERY UNSTABLE CONDITIONS FOR FIRE
WEATHER ZONES 658 AND 659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 22 percent.

* TEMPERATURES...In the upper 70s to 80s.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$
233 
WWUS86 KSEW 131850
RFWSEW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Seattle WA
1150 AM PDT Fri Aug 13 2021

WAZ658-659-140500-
/O.CON.KSEW.FW.W.0002.000000T0000Z-210814T0500Z/
West Slopes of the North Cascades Generally above 1500 Feet-
West Slopes of the Central Cascades Generally above 1500 Feet-
1150 AM PDT Fri Aug 13 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT THIS
EVENING FOR HOT, DRY AND VERY UNSTABLE CONDITIONS FOR FIRE
WEATHER ZONES 658 AND 659...

* AFFECTED AREA...Fire Weather Zone 658 West Slopes of the North 
  Cascades Generally above 1500 Feet and Fire Weather Zone 659 
  West Slopes of the Central Cascades Generally above 1500 Feet.

* RELATIVE HUMIDITY...As low as 22 percent.

* TEMPERATURES...In the upper 70s and 80s with 90s in the lowest
  elevations.

* HAINES...6.

* IMPACTS...A dry and very unstable air mass with warm 
  temperatures can contribute to active fire behavior. In 
  western Washington, significant growth on existing fires takes 
  place under such conditions. If a fire were to begin, air 
  quality may diminish in the surrounding area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either imminent or occurring now. Any fires that develop will
likely spread quickly. Outdoor burning is not recommended.

&&

$$

The office that day

Everything else NWS Seattle, WA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 4:34 AM PDTFire Weather WatchSEWKing, Lewis, Pierce, Skagit, Skamania, Snohomish and 1 more9 hr

Nearby

Red 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.