Alert archive / California / Winter Storm Watches in 2021

Winter Storm Watch 10, NWS Eureka, CA

December 24, 2021Del Norte County, Humboldt County, Mendocino County, California

NWS Eureka, CA issued this winter storm watch at Dec 24, 2021, 10:01 AM PST for Del Norte County, Humboldt County, Mendocino County, California. It took effect at Dec 26, 2021, 10:00 PM PST. It was in force for .

The area

The counties it named.

The facts

Issued
Dec 24, 2021, 10:01 AM PST (18:01 UTC)
In effect from
Dec 26, 2021, 10:00 PM PST
Expired
Dec 26, 2021, 4:37 AM PST
In force
Issued by
NWS Eureka, CA

Counties Del Norte County, CA, Humboldt County, CA, Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 47 km from the middle of the area, began a volume at 18:03 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 6.0 hours before the alert went out and 210 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, Medford/Jackson, OR at 12:00Z on 2021-12-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 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, Medford/Jackson, OR at 12:00Z on 2021-12-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 213 square meters per square second.1939587897Sfc1 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
702 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

324 
WWUS46 KEKA 241801
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1001 AM PST Fri Dec 24 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems will aid in lowering
snow levels to as low as 2000 feet by Saturday afternoon, and
then occasionally sea level Saturday night through Monday morning.
Periods of heavy showers spreading across the cold airmass will 
favor significant mountain snowfall beginning this afternoon and 
lasting through Monday morning. Travel across mountain roadways 
and highway passes will subsequently be difficult if not 
impossible.

CAZ104-250215-
/O.EXA.KEKA.WS.W.0010.211224T1800Z-211227T1800Z/
Southwestern Humboldt-
1001 AM PST Fri Dec 24 2021

...WINTER STORM WARNING IN EFFECT UNTIL 10 AM PST MONDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 7 to 24 
  inches.

* WHERE...Southwestern Humboldt County.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning or evening
  commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ102-105>108-110-111-114-250215-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
1001 AM PST Fri Dec 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 7 to 24
  inches. Winds gusting as high as 35 mph.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning or evening 
  commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ101-103-109-112-113-115-250215-
/O.NEW.KEKA.WS.A.0010.211226T0000Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
Southern Lake-
1001 AM PST Fri Dec 24 2021

...WINTER STORM WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
MONDAY MORNING...

* WHAT...Heavy snow possible. Total snow accumulations of 3 to 9 
  inches possible.

* WHERE...Portions of northwest California.

* WHEN...From Saturday afternoon through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$
7 follow-up statements
855 
WWUS46 KEKA 242254
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
254 PM PST Fri Dec 24 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems will aid in lowering
snow levels to as low as 2000 feet this evening, and then 
occasionally sea level Saturday night through Monday morning. 
Periods of heavy showers spreading across the cold airmass will 
favor significant mountain snowfall lasting through Monday 
morning. Travel across mountain roadways and highway passes will 
subsequently be difficult if not impossible.

CAZ102-104>108-110-111-114-250700-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
254 PM PST Fri Dec 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 7 to 24 
  inches.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning or evening 
  commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ101-103-109-112-113-115-250700-
/O.CON.KEKA.WS.A.0010.211226T0000Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
Southern Lake-
254 PM PST Fri Dec 24 2021

...WINTER STORM WATCH REMAINS IN EFFECT FROM SATURDAY AFTERNOON
THROUGH MONDAY MORNING...

* WHAT...Heavy snow possible. Total snow accumulations of 2 to 8 
  inches possible.

* WHERE...Portions of northwest California.

* WHEN...From Saturday afternoon through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$
326 
WWUS46 KEKA 250645
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1045 PM PST Fri Dec 24 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems will aid in lowering
snow levels to as low as 2000 feet this evening, and then
occasionally sea level Saturday night through Monday morning.
Periods of heavy showers spreading across the cold airmass will
favor significant mountain snowfall lasting through Monday
morning. Travel across mountain roadways and highway passes will
subsequently be difficult if not impossible.

CAZ102-104>108-110-111-114-251400-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
1045 PM PST Fri Dec 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 24 to 48 
  inches.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ101-103-109-112-113-115-251400-
/O.CON.KEKA.WS.A.0010.211226T0000Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
Southern Lake-
1045 PM PST Fri Dec 24 2021

...WINTER STORM WATCH REMAINS IN EFFECT FROM SATURDAY AFTERNOON
THROUGH MONDAY MORNING...

* WHAT...Heavy snow possible. Total snow accumulations of 1 to 8 
  inches possible.

* WHERE...Portions of northwest California.

* WHEN...From Saturday afternoon through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$
451 
WWUS46 KEKA 251337
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
537 AM PST Sat Dec 25 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems has lowered snow 
levels to around 2000 feet this morning, and may occasionally drop
snow levels to sea level Saturday night through Monday morning. 
Periods of heavy showers spreading across the cold airmass will 
favor significant mountain snowfall lasting through Monday 
morning. Travel across mountain roadways and highway passes will 
subsequently be difficult if not impossible.

CAZ104>106-252145-
/O.NEW.KEKA.WW.Y.0024.211226T0300Z-211226T1600Z/
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-
537 AM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...
...WINTER WEATHER ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO
8 AM PST SUNDAY...

* WHAT...For the Winter Storm Warning, heavy snow. Additional snow
  accumulations of 24 to 38 inches. For the Winter Weather
  Advisory, snow expected. Total snow accumulations of 1 to 5 
  inches.

* WHERE...Southwestern Humboldt, Northern Humboldt Interior and 
  Southern Humboldt Interior Counties.

* WHEN...For the Winter Storm Warning, until 10 AM PST Monday. 
  For the Winter Weather Advisory, from 7 PM this evening to 8 
  AM PST Sunday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

Slow down and use caution while traveling. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ110-252145-
/O.NEW.KEKA.WW.Y.0024.211226T0600Z-211226T1800Z/
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Northwestern Mendocino Interior-
537 AM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...
...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO
10 AM PST SUNDAY...

* WHAT...For the Winter Storm Warning, heavy snow. Additional snow
  accumulations of 5 to 17 inches. For the Winter Weather 
  Advisory, snow expected. Total snow accumulations of 2 to 4 
  inches.

* WHERE...Northwestern Mendocino Interior County.

* WHEN...For the Winter Storm Warning, until 10 AM PST Monday. 
  For the Winter Weather Advisory, from 10 PM this evening to 10 
  AM PST Sunday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

Slow down and use caution while traveling. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ102-107-108-111-114-252145-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Northern Trinity-Southern Trinity-
Northeastern Mendocino Interior-Northern Lake-
537 AM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 24 to 48 
  inches.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ101-103-252145-
/O.NEW.KEKA.WW.Y.0024.211226T0300Z-211226T1600Z/
/O.EXT.KEKA.WS.A.0010.211227T0000Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-
537 AM PST Sat Dec 25 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO
8 AM PST SUNDAY...
...WINTER STORM WATCH NOW IN EFFECT FROM SUNDAY AFTERNOON THROUGH
MONDAY MORNING...

* WHAT...For the Winter Weather Advisory, wet snow expected. Total
  snow accumulations of up to 2 to 4 inches. For the Winter Storm
  Watch, heavy snow possible. Total snow accumulations of 1 to 3
  inches possible down to sea level.

* WHERE...Coastal Del Norte and Northern Humboldt Coast Counties.

* WHEN...For the Winter Weather Advisory, from 7 PM this evening 
  to 8 AM PST Sunday. For the Winter Storm Watch, from Sunday 
  afternoon through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ109-112-113-115-252145-
/O.NEW.KEKA.WW.Y.0024.211226T0600Z-211226T1800Z/
/O.EXT.KEKA.WS.A.0010.211227T0000Z-211227T1800Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
537 AM PST Sat Dec 25 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO
10 AM PST SUNDAY...
...WINTER STORM WATCH NOW IN EFFECT FROM SUNDAY AFTERNOON THROUGH
MONDAY MORNING...

* WHAT...For the Winter Weather Advisory, snow expected. Total 
  snow accumulations of up to two inches. For the Winter Storm 
  Watch, heavy snow possible. Total snow accumulations of up to 
  4 inches possible.

* WHERE...Mendocino Coast, Southwestern Mendocino Interior, 
  Southeastern Mendocino Interior and Southern Lake Counties.

* WHEN...For the Winter Weather Advisory, from 10 PM this 
  evening to 10 AM PST Sunday. For the Winter Storm Watch, from 
  Sunday afternoon through Monday morning.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$
693 
WWUS46 KEKA 251608
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
808 AM PST Sat Dec 25 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems has lowered snow
levels to around 2000 feet this morning, and may occasionally
drop snow levels to sea level Saturday night through Monday
morning. Periods of heavy showers spreading across the cold
airmass will favor significant mountain snowfall lasting through
Monday morning. Travel across mountain roadways and highway
passes will subsequently be difficult if not impossible.

CAZ104>106-260015-
/O.CAN.KEKA.WW.Y.0024.211226T0300Z-211226T1600Z/
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-
808 AM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...For the Winter Storm Warning, heavy snow. Additional snow
  accumulations of 3 to 16 inches. 

* WHERE...Northern Humboldt Interior, Southwestern Humboldt and 
  Southern Humboldt Interior Counties.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ110-260015-
/O.CAN.KEKA.WW.Y.0024.211226T0600Z-211226T1800Z/
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Northwestern Mendocino Interior-
808 AM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 3 to 13 
  inches.

* WHERE...Northwestern Mendocino Interior County.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ102-107-108-111-114-260015-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Northern Trinity-Southern Trinity-
Northeastern Mendocino Interior-Northern Lake-
808 AM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 7 to 14
  inches at low elevations and 20 to 38 inches above 2000 feet.

* WHERE...Southern Trinity, Del Norte Interior, Northeastern 
  Mendocino Interior, Northern Trinity and Northern Lake 
  Counties.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ101-103-260015-
/O.CON.KEKA.WW.Y.0024.211226T0300Z-211226T1600Z/
/O.CON.KEKA.WS.A.0010.211227T0000Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-
808 AM PST Sat Dec 25 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 7 PM THIS
EVENING TO 8 AM PST SUNDAY...
...WINTER STORM WATCH REMAINS IN EFFECT FROM SUNDAY AFTERNOON
THROUGH MONDAY MORNING...

* WHAT...For the Winter Weather Advisory, wet snow expected. Total
  snow accumulations of up to 2 inches. For the Winter Storm
  Watch, heavy snow possible. Total snow accumulations of 1 to 4 
  inches possible.

* WHERE...Coastal Del Norte and Northern Humboldt Coast Counties.

* WHEN...For the Winter Weather Advisory, from 7 PM this evening 
  to 8 AM PST Sunday. For the Winter Storm Watch, from Sunday 
  afternoon through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ109-112-113-115-260015-
/O.CON.KEKA.WW.Y.0024.211226T0600Z-211226T1800Z/
/O.CON.KEKA.WS.A.0010.211227T0000Z-211227T1800Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
808 AM PST Sat Dec 25 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 10 PM THIS
EVENING TO 10 AM PST SUNDAY...
...WINTER STORM WATCH REMAINS IN EFFECT FROM SUNDAY AFTERNOON
THROUGH MONDAY MORNING...

* WHAT...For the Winter Weather Advisory, snow expected. Total 
  snow accumulations of up to two inches. For the Winter Storm 
  Watch, heavy snow possible. Total snow accumulations of up to 
  4 inches possible.

* WHERE...Mendocino Coast, Southeastern Mendocino Interior, 
  Southwestern Mendocino Interior and Southern Lake Counties.

* WHEN...For the Winter Weather Advisory, from 10 PM this 
  evening to 10 AM PST Sunday. For the Winter Storm Watch, from 
  Sunday afternoon through Monday morning.

* IMPACTS...Travel could be very difficult. The hazardous 
  conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$
325 
WWUS46 KEKA 252246
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
246 PM PST Sat Dec 25 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems has lowered snow
levels to around 1500 feet today, and may occasionally drop snow 
levels to sea level  tonight through Monday morning. Periods of 
heavy showers spreading across the cold airmass will favor 
significant mountain snowfall lasting through Monday morning. 
Travel across mountain roadways and highway passes will 
subsequently be difficult if not impossible.

CAZ101-103-260700-
/O.UPG.KEKA.WW.Y.0024.211226T0300Z-211226T1600Z/
/O.EXB.KEKA.WS.W.0010.211226T0600Z-211226T1800Z/
/O.EXT.KEKA.WS.A.0010.211227T0600Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-
246 PM PST Sat Dec 25 2021

...WINTER STORM WARNING IN EFFECT FROM 10 PM THIS EVENING TO
10 AM PST SUNDAY...
...WINTER STORM WATCH NOW IN EFFECT FROM SUNDAY EVENING THROUGH
MONDAY MORNING...

* WHAT...For the Winter Storm Warning, heavy snow expected. Total
  snow accumulations of 2 to 3 inches. For the Winter Storm 
  Watch, heavy snow possible. Total snow accumulations of 2 to 3 
  inches possible.

* WHERE...Coastal Del Norte and Northern Humboldt Coast Counties.

* WHEN...For the Winter Storm Warning, from 10 PM this evening 
  to 10 AM PST Sunday. For the Winter Storm Watch, from Sunday 
  evening through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning commute including
  highway 101.

* ADDITIONAL DETAILS...Snowfall will likely be wet and mixed with
  rain. Snowfall will be sporadic with accumulation most likely a
  couple hundred feet above sea level. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ102-104>108-110-111-114-260700-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
246 PM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 7 to 14
  inches at low elevations and 20 to 38 inches above 2000 feet.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions will impact highways 299, 101, 199, 36, and
  3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ109-112-113-115-260700-
/O.EXT.KEKA.WS.A.0010.211227T0600Z-211227T1800Z/
/O.CON.KEKA.WW.Y.0024.211226T0600Z-211226T1800Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
246 PM PST Sat Dec 25 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 10 PM THIS
EVENING TO 10 AM PST SUNDAY...
...WINTER STORM WATCH NOW IN EFFECT FROM SUNDAY EVENING THROUGH
MONDAY MORNING...

* WHAT...For the Winter Weather Advisory, snow expected. Total
  snow accumulations of up to 2 inches. For the Winter Storm
  Watch, heavy snow possible. Total snow accumulations of 2 to 5 
  inches possible.

* WHERE...Mendocino Coast, Southeastern Mendocino Interior, 
  Southwestern Mendocino Interior and Southern Lake Counties.

* WHEN...For the Winter Weather Advisory, from 10 PM this 
  evening to 10 AM PST Sunday. For the Winter Storm Watch, from 
  Sunday evening through Monday morning.

* IMPACTS...Travel could be very difficult to impossible along
  portions of highway 101. The hazardous conditions could impact 
  the morning commute.

* ADDITIONAL DETAILS...Snowfall will likely be wet and mixed with
  rain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$
747 
WWUS46 KEKA 260645
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1045 PM PST Sat Dec 25 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems has lowered snow
levels to around 1500 feet today, and may occasionally drop snow
levels to sea level  tonight through Monday morning. Periods of
heavy showers spreading across the cold airmass will favor
significant mountain snowfall lasting through Monday morning.
Travel across mountain roadways and highway passes will
subsequently be difficult if not impossible.

CAZ101-103-261445-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211226T1800Z/
/O.CON.KEKA.WS.A.0010.211227T0600Z-211227T1800Z/
Coastal Del Norte-Northern Humboldt Coast-
1045 PM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
SUNDAY...
...WINTER STORM WATCH REMAINS IN EFFECT FROM SUNDAY EVENING
THROUGH MONDAY MORNING...

* WHAT...For the Winter Storm Warning, heavy snow. Additional snow
  accumulations of 1 to 3 inches. For the Winter Storm Watch,
  heavy snow possible. Total snow accumulations of 1 to 3 inches
  possible. Winds gusting as high as 30 mph.

* WHERE...Coastal Del Norte and Northern Humboldt Coast Counties.

* WHEN...For the Winter Storm Warning, until 10 AM PST Sunday. 
  For the Winter Storm Watch, from Sunday evening through Monday 
  morning.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ102-104>108-110-111-114-261445-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
1045 PM PST Sat Dec 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 24 to 34
  inches. Winds gusting as high as 35 mph.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ109-112-113-115-261445-
/O.CON.KEKA.WW.Y.0024.000000T0000Z-211226T1800Z/
/O.CON.KEKA.WS.A.0010.211227T0600Z-211227T1800Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
1045 PM PST Sat Dec 25 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST
SUNDAY...
...WINTER STORM WATCH REMAINS IN EFFECT FROM SUNDAY EVENING
THROUGH MONDAY MORNING...

* WHAT...For the Winter Weather Advisory, snow. Additional snow 
  accumulations of up to 3 inches. For the Winter Storm Watch, 
  heavy snow possible. Total snow accumulations of up to 5 
  inches possible.

* WHERE...Mendocino Coast, Southeastern Mendocino Interior, 
  Southwestern Mendocino Interior and Southern Lake Counties.

* WHEN...For the Winter Weather Advisory, until 10 AM PST 
  Sunday. For the Winter Storm Watch, from Sunday evening 
  through Monday morning.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning commute.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Monitor the latest forecasts for updates on this situation. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$
182 
WWUS46 KEKA 261237
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
437 AM PST Sun Dec 26 2021

...HEAVY MOUNTAIN SNOW EXPECTED DURING THE CHRISTMAS HOLIDAY...

.A series of cold upper level storm systems has lowered snow
levels to around 500 to 1000 feet early this morning. These will
likely rise later this morning before dropping again tonight 
through Monday morning. Periods of heavy showers spreading across 
the cold airmass will favor significant mountain snowfall lasting 
through Monday morning. Travel across mountain roadways and 
highway passes will subsequently be difficult if not impossible.

CAZ101-103-262045-
/O.UPG.KEKA.WS.A.0010.211227T0600Z-211227T1800Z/
/O.NEW.KEKA.WW.Y.0025.211227T0900Z-211227T1800Z/
/O.CON.KEKA.WS.W.0010.000000T0000Z-211226T1800Z/
Coastal Del Norte-Northern Humboldt Coast-
437 AM PST Sun Dec 26 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST THIS
MORNING...
...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM TO 10 AM PST
MONDAY...

* WHAT...For the Winter Storm Warning, heavy wet snow. 
  Additional snow accumulations of up to two inches. For the 
  Winter Weather Advisory, snow expected. Total snow 
  accumulations of up to two inches.

* WHERE...Coastal Del Norte and Northern Humboldt Coast Counties.

* WHEN...For the Winter Storm Warning, until 10 AM PST this 
  morning. For the Winter Weather Advisory, from 1 AM to 10 AM 
  PST Monday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning commute.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

Slow down and use caution while traveling. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ102-104>108-110-111-114-262045-
/O.CON.KEKA.WS.W.0010.000000T0000Z-211227T1800Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
437 AM PST Sun Dec 26 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST
MONDAY...

* WHAT...Heavy snow. Additional snow accumulations of 24 to 34 
  inches. Winds gusting as high as 35 mph.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST Monday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

CAZ109-112-113-115-262045-
/O.UPG.KEKA.WS.A.0010.211227T0600Z-211227T1800Z/
/O.NEW.KEKA.WW.Y.0025.211227T0900Z-211227T1800Z/
/O.CON.KEKA.WW.Y.0024.000000T0000Z-211226T1800Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
437 AM PST Sun Dec 26 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST THIS
MORNING...
...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM TO 10 AM PST
MONDAY...

* WHAT...For the first Winter Weather Advisory, wet snow.
  Additional snow accumulations of up to one inch. For the second
  Winter Weather Advisory, snow expected. Total snow accumulations
  of mostly 1 to 2 inches expected, locally up to 3 inches.

* WHERE...Mendocino Coast, Southwestern Mendocino Interior, 
  Southeastern Mendocino Interior and Southern Lake Counties.

* WHEN...For the first Winter Weather Advisory, until 10 AM PST 
  this morning. For the second Winter Weather Advisory, from 1 
  AM to 10 AM PST Monday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state of California can be
obtained by calling 1-800-GAS-ROAD.

&&

$$

The office that day

Everything else NWS Eureka, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 24, 2:53 AM PSTGale WarningEKA12 hr

Nearby

Winter Storm Watches in California, 2021Every winter storm watch 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.