Alert archive / Washington / Wind Chill Advisories in 2021

Wind Chill Advisory 2, NWS Seattle, WA

December 28, 2021San Juan County, Washington

NWS Seattle, WA issued this wind chill advisory at Dec 28, 2021, 3:13 AM PST for San Juan County, Washington. It took effect at Dec 28, 2021, 7:00 PM PST. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued
Dec 28, 2021, 3:13 AM PST (11:13 UTC)
In effect from
Dec 28, 2021, 7:00 PM PST
Expired
Dec 29, 2021, 1:00 PM PST
In force
18 hr
Issued by
NWS Seattle, WA

County San Juan County, WA

The radar

The Seattle radar (KATX), 54 km from the middle of the area, began a volume at 11:12 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 00:00Z, 11.2 hours before the alert went out and 127 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 00:00Z on 2021-12-28Temperature 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 00:00Z on 2021-12-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 223 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
553 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
338 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

988 
WWUS46 KSEW 281113
WSWSEW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Seattle WA
313 AM PST Tue Dec 28 2021

WAZ001-503-290000-
/O.NEW.KSEW.WC.Y.0002.211229T0300Z-211229T2100Z/
San Juan County-Western Whatcom County-
including Friday Harbor, Eastsound, Bellingham, Blaine, 
Point Roberts, Ferndale, Lynden, Sumas, and Sudden Valley
313 AM PST Tue Dec 28 2021

...WIND CHILL ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO 1 PM
PST WEDNESDAY...

* WHAT...Very cold wind chills expected. Wind chills as low as 10
  below zero.

* WHERE...San Juan County, including Stuart Island, Waldron 
  Island, Orcas Island, San Juan Island, Lopez Island, Blakely 
  Island, and Decatur Island and Lowlands of western Whatcom 
  County, including Point Roberts, Lummi Island, Bellingham, and 
  Sumas.

* WHEN...From 7 PM this evening to 1 PM PST Wednesday.

* IMPACTS...Wind chills this cold can cause frostbite on exposed
  skin in as little as 30 minutes. Hypothermia is also a risk. 

* ADDITIONAL DETAILS...The coldest wind chills will occur after
  midnight tonight and Wednesday morning. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

http://www.weather.gov/seattle
3 follow-up statements
038 
WWUS46 KSEW 282307
WSWSEW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Seattle WA
307 PM PST Tue Dec 28 2021

WAZ001-503-291200-
/O.CON.KSEW.WC.Y.0002.211229T0300Z-211229T2100Z/
San Juan County-Western Whatcom County-
including Friday Harbor, Eastsound, Bellingham, Blaine, 
Point Roberts, Ferndale, Lynden, Sumas, and Sudden Valley
307 PM PST Tue Dec 28 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM 7 PM THIS EVENING
TO 1 PM PST WEDNESDAY...

* WHAT...Very cold wind chills expected. Wind chills as low as 
  10 below zero.

* WHERE...Lowlands of western Whatcom County, including Point 
  Roberts, Lummi Island, Bellingham, and Sumas and San Juan 
  County, including Stuart Island, Waldron Island, Orcas Island, 
  San Juan Island, Lopez Island, Blakely Island, and Decatur 
  Island.

* WHEN...From 7 PM this evening to 1 PM PST Wednesday.

* IMPACTS...Wind chills this cold can cause frostbite on exposed
  skin in as little as 30 minutes. Hypothermia is also a risk. 

* ADDITIONAL DETAILS...The coldest wind chills will occur after
  midnight tonight and Wednesday morning. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

http://www.weather.gov/seattle
202 
WWUS46 KSEW 291121
WSWSEW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Seattle WA
321 AM PST Wed Dec 29 2021

WAZ567-300000-
/O.NEW.KSEW.WW.Y.0041.211230T0600Z-211230T2000Z/
Cascades of Whatcom and Skagit Counties-
including Concrete, Hamilton, Lyman, Maple Falls, Deming, 
and Newhalem
321 AM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO
NOON PST THURSDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 9 
  inches.

* WHERE...Cascade mountains and valleys of Whatcom and Skagit 
  Counties, including Maple Falls, the Mount Baker Ski Area, 
  Newhalem, Lyman, and Concrete.

* WHEN...From 10 PM this evening to noon PST Thursday.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

For the latest road conditions in Washington state, call 5 1 1.

&&

$$

WAZ568-569-300000-
/O.NEW.KSEW.WW.Y.0041.211230T0900Z-211231T0300Z/
Cascades of Snohomish and King Counties-
Cascades of Pierce and Lewis Counties-
including Darrington, Baring, Stevens Pass, Skykomish, 
Snoqualmie Pass, Morton, Ashford, Packwood, Randle, Paradise, 
and Longmire
321 AM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM TO 7 PM PST
THURSDAY...

* WHAT...Snow expected. Total snow accumulations of 6 to 12 
  inches.

* WHERE...Cascade mountains and valleys of Snohomish and King 
  Counties, including Darrington, Index, Skykomish, Stevens 
  Pass, and Snoqualmie Pass and Cascade mountains and valleys of 
  Pierce and Lewis Counties, including the Crystal Mountain Ski 
  Area, Paradise on Mount Rainier, Ashford, Randle, and Packwood.

* WHEN...From 1 AM to 7 PM PST Thursday.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

For the latest road conditions in Washington state, call 5 1 1.

&&

$$

WAZ001-503-292100-
/O.CON.KSEW.WC.Y.0002.000000T0000Z-211229T2100Z/
San Juan County-Western Whatcom County-
including Friday Harbor, Eastsound, Bellingham, Blaine, 
Point Roberts, Ferndale, Lynden, Sumas, and Sudden Valley
321 AM PST Wed Dec 29 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL 1 PM PST THIS
AFTERNOON...

* WHAT...Very cold wind chills continued. Wind chills as low as 
  10 below zero.

* WHERE...Lowlands of western Whatcom County, including Point 
  Roberts, Lummi Island, Bellingham, and Sumas and San Juan 
  County, including Stuart Island, Waldron Island, Orcas Island, 
  San Juan Island, Lopez Island, Blakely Island, and Decatur 
  Island.

* WHEN...Until 1 PM PST this afternoon.

* IMPACTS...Wind chills this cold can cause frostbite on exposed
  skin in as little as 30 minutes. Hypothermia is also a risk. 

* ADDITIONAL DETAILS...The coldest wind chill values will occur 
  this morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

http://www.weather.gov/seattle
127 
WWUS46 KSEW 292055
WSWSEW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Seattle WA
1255 PM PST Wed Dec 29 2021

WAZ001-503-292200-
/O.EXP.KSEW.WC.Y.0002.000000T0000Z-211229T2100Z/
San Juan County-Western Whatcom County-
including Friday Harbor, Eastsound, Bellingham, Blaine, 
Point Roberts, Ferndale, Lynden, Sumas, and Sudden Valley
1255 PM PST Wed Dec 29 2021

...WIND CHILL ADVISORY WILL EXPIRE AT 1 PM PST THIS AFTERNOON...

Recent observations indicate that winds have eased over the area
and temperatures have risen to near 20 degrees. Winds will still
remain breezy in spots through the afternoon, with wind chills in
the single digits to low teens.

$$

WAZ567-300000-
/O.CON.KSEW.WW.Y.0041.211230T0600Z-211230T2000Z/
Cascades of Whatcom and Skagit Counties-
including Concrete, Hamilton, Lyman, Maple Falls, Deming, 
and Newhalem
1255 PM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 10 PM THIS
EVENING TO NOON PST THURSDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 9 
  inches.

* WHERE...Cascade mountains and valleys of Whatcom and Skagit 
  Counties, including Maple Falls, the Mount Baker Ski Area, 
  Newhalem, Lyman, and Concrete.

* WHEN...From 10 PM this evening to noon PST Thursday.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

For the latest road conditions in Washington state, call 5 1 1.

&&

$$

WAZ568-569-300000-
/O.CON.KSEW.WW.Y.0041.211230T0900Z-211231T0300Z/
Cascades of Snohomish and King Counties-
Cascades of Pierce and Lewis Counties-
including Darrington, Baring, Stevens Pass, Skykomish, 
Snoqualmie Pass, Morton, Ashford, Packwood, Randle, Paradise, 
and Longmire
1255 PM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 1 AM TO 7 PM
PST THURSDAY...

* WHAT...Snow expected. Total snow accumulations of 4 to 12 
  inches.

* WHERE...Cascade mountains and valleys of Pierce and Lewis 
  Counties, including the Crystal Mountain Ski Area, Paradise on 
  Mount Rainier, Ashford, Randle, and Packwood and Cascade 
  mountains and valleys of Snohomish and King Counties, 
  including Darrington, Index, Skykomish, Stevens Pass, and 
  Snoqualmie Pass.

* WHEN...From 1 AM to 7 PM PST Thursday.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

For the latest road conditions in Washington state, call 5 1 1.

&&

$$

http://www.weather.gov/seattle

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 27, 11:22 PM PSTSmall Craft AdvisorySEW8 hr
Dec 28, 2:35 AM PSTGale WatchSEW12 hr
Dec 28, 2:35 AM PSTSmall Craft AdvisorySEW34 hr
Dec 28, 3:13 AM PSTWind AdvisorySEWSan Juan34 hr
Dec 28, 2:22 PM PSTGale WarningSEW23 hr
Dec 28, 2:22 PM PSTHeavy Freezing Spray AdvisorySEW22 hr

Nearby

Wind Chill Advisories in Washington, 2021Every wind chill advisory 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.