Alert archive / California / Winter Weather Advisories in 2021

Winter Weather Advisory 13, NWS Eureka, CA

March 7, 20215 counties in California

NWS Eureka, CA issued this winter weather advisory at Mar 7, 2021, 2:09 PM PST for 5 counties in California. It took effect at Mar 8, 2021, 1:00 PM PST. It was in force for 45 hr.

The area

The counties it named.

The facts

Issued
Mar 7, 2021, 2:09 PM PST (22:09 UTC)
In effect from
Mar 8, 2021, 1:00 PM PST
Expired
Mar 10, 2021, 10:00 AM PST
In force
45 hr
Issued by
NWS Eureka, CA

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

The radar

The Eureka (Bunker Hill) radar (KBHX), 75 km from the middle of the area, began a volume at 22:08 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, 10.2 hours before the alert went out and 233 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 2021-03-07Temperature 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, Medford/Jackson, OR at 12:00Z on 2021-03-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 200 square meters per square second.1939587897117Sfc1 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
1554 m above ground
0-6 km bulk shear
91 kt
0-1 km storm-relative helicity
200 m²/s²
0-3 km storm-relative helicity
299 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

009 
WWUS46 KEKA 072209
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
209 PM PST Sun Mar 7 2021

...SNOW SHOWERS EXPECTED MONDAY THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south across
the northeastern Pacific through mid week. An extended period of
showery weather will occur with the storm system. Showers across
the mountains will produce accumulating snow. Travel impacts will
be possible as a result across mountain roadways and highway
passes.

CAZ102-105>108-110-111-114-080615-
/O.NEW.KEKA.WW.Y.0013.210308T2100Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
209 PM PST Sun Mar 7 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 PM MONDAY TO 4 AM PST
WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Total snow accumulations
  from 4 to 12 inches.

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

* WHEN...From 1 PM Monday to 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry
  Summit on highway 299, Scott Mountain Summit on highway 3,
  Oregon Mountain on highway 299, South Fork Mountain on highway
  36, and additional sections of highway 36 and 3 in Trinity
  County.

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.

&&

$$
11 follow-up statements
714 
WWUS46 KEKA 080602
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1002 PM PST Sun Mar 7 2021

...SNOW SHOWERS EXPECTED MONDAY THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south across
the northeastern Pacific through mid week. An extended period of
showery weather will occur with the storm system. Showers across
the mountains will produce accumulating snow. Travel impacts will
be possible as a result across mountain roadways and highway
passes.

CAZ102-105>108-110-111-114-081300-
/O.CON.KEKA.WW.Y.0013.210308T2100Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
1002 PM PST Sun Mar 7 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 1 PM MONDAY TO
4 AM PST WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow expected above 2,000 feet. Total snow accumulations
  from 4 to 12 inches.

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

* WHEN...From 1 PM Monday to 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry
  Summit on Highway 299, Scott Mountain Summit on Highway 3,
  Oregon Mountain on Highway 299, South Fork Mountain on Highway
  36, and additional sections of Highways 36 and 3 in Trinity
  County.

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.

&&

$$
405 
WWUS46 KEKA 081126
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
326 AM PST Mon Mar 8 2021

...SNOW SHOWERS EXPECTED TODAY THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south across
the northeastern Pacific through mid week. An extended period of
showery weather will occur with the storm system. Showers across
the mountains will produce accumulating snow. Travel impacts will
be possible as a result across mountain roadways and highway
passes. Snow levels will fluctuate from 2,000 to 3,000 feet. 

CAZ102-105>108-110-111-114-081930-
/O.CON.KEKA.WW.Y.0013.210308T2100Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
326 AM PST Mon Mar 8 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 1 PM THIS
AFTERNOON TO 4 AM PST WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Total snow accumulations
  of 4 to 12 inches.

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

* WHEN...From 1 PM this afternoon to 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry
  Summit on Highway 299, Scott Mountain Summit on Highway 3,
  Oregon Mountain on Highway 299, South Fork Mountain on Highway
  36, and additional sections of Highways 36 and 3 in Trinity
  County.

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.

&&

$$
957 
WWUS46 KEKA 081658
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
858 AM PST Mon Mar 8 2021

...SNOW SHOWERS EXPECTED TODAY THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through mid week. An extended period of showery 
weather will occur with the storm system. Showers across the 
mountains will produce accumulating snow. Travel impacts will be 
possible as a result across mountain roadways and highway passes.

CAZ102-105>108-110-111-114-090100-
/O.CON.KEKA.WW.Y.0013.210308T2100Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
858 AM PST Mon Mar 8 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 1 PM THIS
AFTERNOON TO 4 AM PST WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Total snow accumulations 
  of 4 to 12 inches.

* WHERE...Southern Trinity, Northeastern Mendocino Interior,
  Northwestern Mendocino Interior, Del Norte Interior, Northern
  Humboldt Interior, Northern Trinity, Southern Humboldt Interior
  and Northern Lake County.

* WHEN...From 1 PM this afternoon to 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry 
  Summit on Highway 299, Scott Mountain Summit on Highway 3, 
  Oregon Mountain on Highway 299, South Fork Mountain on Highway 
  36, and additional sections of Highways 36 and 3 in Trinity 
  County.

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.

&&

$$
179 
WWUS46 KEKA 082211
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
211 PM PST Mon Mar 8 2021

...SNOW SHOWERS EXPECTED THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through mid week. An extended period of showery
weather will occur with the storm system. Showers across the
mountains will produce accumulating snow. Travel impacts will be
possible as a result across mountain roadways and highway passes.

CAZ102-105>108-110-111-114-090615-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
211 PM PST Mon Mar 8 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Total snow accumulations 
  of 4 to 12 inches.

* WHERE...Southern Trinity, Northeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Del Norte Interior, Northern 
  Humboldt Interior, Northern Trinity, Southern Humboldt 
  Interior and Northern Lake County.

* WHEN...Through 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry 
  Summit on Highway 299, Scott Mountain Summit on Highway 3, 
  Oregon Mountain on Highway 299, South Fork Mountain on Highway 
  36, and additional sections of Highways 36 and 3 in Trinity 
  County.

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.

&&

$$
427 
WWUS46 KEKA 090912
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
112 AM PST Tue Mar 9 2021

...SNOW SHOWERS EXPECTED THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through mid week. An extended period of showery
weather will occur with the storm system. Showers across the
mountains will produce accumulating snow. Travel impacts will be
possible as a result across mountain roadways and highway passes.

CAZ102-105>108-110-111-114-091715-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
112 AM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Total snow accumulations 
  of 4 to 12 inches.

* WHERE...Southern Trinity, Northeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Del Norte Interior, Northern 
  Humboldt Interior, Northern Trinity, Southern Humboldt 
  Interior and Northern Lake County.

* WHEN...Through 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry 
  Summit on Highway 299, Scott Mountain Summit on Highway 3, 
  Oregon Mountain on Highway 299, South Fork Mountain on Highway 
  36, and additional sections of Highways 36 and 3 in Trinity 
  County.

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.

&&

$$
921 
WWUS46 KEKA 091110
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
310 AM PST Tue Mar 9 2021

...SNOW SHOWERS EXPECTED THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through Wednesday. An extended period of showery 
weather will continue with the storm system. Showers across the 
mountains will produce accumulating snow. Travel impacts will be 
possible as a result across mountain roadways and highway passes.
Showers will diminish Tuesday night and Wednesday. 

CAZ102-105>108-091915-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
310 AM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
WEDNESDAY ABOVE 2000 FEET...

* WHAT...Snow above 2000 feet. Additional snow accumulations of 3
  to 6 inches with local amounts up to a foot at the higher
  elevations.

* WHERE...Southern Trinity, Del Norte Interior, Northern Humboldt
  Interior, Northern Trinity, and Southern Humboldt Interior.

* WHEN...Until 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry 
  Summit on Highway 299, Scott Mountain Summit on Highway 3, 
  Oregon Mountain on Highway 299, South Fork Mountain on Highway 
  36, and additional sections of Highways 36 and 3 in Trinity 
  County.

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.

&&

$$

CAZ110-111-114-091915-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1200Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
310 AM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
WEDNESDAY ABOVE 3000 FEET...

* WHAT...Snow above 3000 feet. Additional snow accumulations of 3
  to 6 inches with local amounts up to a foot at the higher
  elevations.

* WHERE...Northeastern Mendocino Interior, Northwestern Mendocino
  Interior, and Northern Lake County.

* WHEN...Until 4 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry 
  Summit on Highway 299, Scott Mountain Summit on Highway 3, 
  Oregon Mountain on Highway 299, South Fork Mountain on Highway 
  36, and additional sections of Highways 36 and 3 in Trinity 
  County.

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.

&&

$$
820 
WWUS46 KEKA 091646
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
846 AM PST Tue Mar 9 2021

...SNOW SHOWERS EXPECTED THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through Wednesday. An extended period of showery
weather will occur with the storm system, and showers over the 
mountains will produce accumulating snow. Travel impacts will be 
possible as a result across mountain roadways and highway passes.

CAZ113-115-100100-
/O.EXB.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Southeastern Mendocino Interior-Southern Lake County-
846 AM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM PST WEDNESDAY
ABOVE 1500 FEET...

* WHAT...Snow above 1500 feet. Additional snow accumulations of 
  up to 5 inches.

* WHERE...Southeastern Mendocino Interior and Southern Lake 
  County Counties.

* WHEN...Until 10 AM PST Wednesday.

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

&&

$$

CAZ102-105>108-110-111-114-100100-
/O.EXT.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
846 AM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 10 AM PST
WEDNESDAY ABOVE 1500 FEET...

* WHAT...Snow above 1500 feet. Additional snow accumulations of 2
  to 6 inches.

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

* WHEN...Until 10 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry
  Summit on Highway 299, Scott Mountain Summit on Highway 3,
  Oregon Mountain on Highway 299, South Fork Mountain on Highway
  36, and additional sections of Highways 36 and 3 in Trinity
  County. Portions of highway 101 near Laytonville may also
  experience several inches of snow, particularly tonight.

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.

&&

$$
880 
WWUS46 KEKA 092213
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
213 PM PST Tue Mar 9 2021

...SNOW SHOWERS EXPECTED THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through Wednesday. An extended period of showery
weather will occur with the storm system, and showers over the
mountains will produce accumulating snow. Travel impacts will be
possible as a result across mountain roadways and highway passes.

CAZ104-109-100615-
/O.EXA.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Southwestern Humboldt-Mendocino Coast-
213 PM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM PST WEDNESDAY
ABOVE 1500 FEET...

* WHAT...Snow above 1500 feet. Additional snow accumulations of 2
  to 6 inches.

* WHERE...Southwestern Humboldt and Mendocino Coast Counties.

* WHEN...Until 10 AM PST Wednesday.

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

&&

$$

CAZ102-105>108-110-111-113>115-100615-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southeastern Mendocino Interior-Northern Lake County-
Southern Lake County-
213 PM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST
WEDNESDAY ABOVE 1500 FEET...

* WHAT...Snow above 1500 feet. Additional snow accumulations of 2
  to 6 inches.

* WHERE...Southern Trinity, Del Norte Interior, Southeastern
  Mendocino Interior, Northwestern Mendocino Interior,
  Northeastern Mendocino Interior, Northern Humboldt Interior,
  Northern Trinity, Southern Humboldt Interior, Northern Lake
  County and Southern Lake County.

* WHEN...Until 10 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry
  Summit on Highway 299, Scott Mountain Summit on Highway 3,
  Oregon Mountain on Highway 299, South Fork Mountain on Highway
  36, and additional sections of Highways 36 and 3 in Trinity
  County. Portions of highway 101 near Laytonville and Rattlesnake
  Summit may also experience several inches of snow tonight.

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.

&&

$$
138 
WWUS46 KEKA 100516
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
916 PM PST Tue Mar 9 2021

...SNOW SHOWERS EXPECTED THROUGH WEDNESDAY...

.A cold upper level storm system will gradually move south along
the west coast through Wednesday. An extended period of showery
weather will occur with the storm system, and showers over the
mountains will produce accumulating snow. Travel impacts will be
possible as a result across mountain roadways and highway passes.

CAZ102-104>111-113>115-101330-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-Mendocino Coast-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southeastern Mendocino Interior-Northern Lake County-
Southern Lake County-
916 PM PST Tue Mar 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST
WEDNESDAY ABOVE 1500 FEET...

* WHAT...Snow above 1500 feet. Additional snow accumulations of 
  up to 5 inches.

* WHERE...Portions of northwest California above 1500 ft.

* WHEN...Until 10 AM PST Wednesday.

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

* ADDITIONAL DETAILS...Highway passes impacted include Berry
  Summit on Highway 299, Scott Mountain Summit on Highway 3,
  Oregon Mountain on Highway 299, South Fork Mountain on Highway
  36, and additional sections of Highways 36 and 3 in Trinity
  County. Portions of highway 101 near Laytonville and Rattlesnake
  Summit may also experience several inches of snow tonight.

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.

&&

$$
271 
WWUS46 KEKA 101319
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
519 AM PST Wed Mar 10 2021

CAZ102-101430-
/O.CAN.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Del Norte Interior-
519 AM PST Wed Mar 10 2021

...WINTER WEATHER ADVISORY IS CANCELLED...

Showers will continue to taper off through this morning.

$$

CAZ104>111-113>115-101800-
/O.CON.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Mendocino Coast-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake County-Southern Lake County-
519 AM PST Wed Mar 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST THIS
MORNING ABOVE 1500 FEET...

* WHAT...Snow above 1500 feet. Additional snow accumulations of 
  up to one inch.

* WHERE...Portions of northwest California.

* WHEN...Until 10 AM PST this morning.

* IMPACTS...Plan on slippery road conditions. 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.

&&

$$
500 
WWUS46 KEKA 101810
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1010 AM PST Wed Mar 10 2021

...Snow Levels Rising Today, but Some Snow Showers Continuing...

.Snow levels around 2000 feet early this morning are on the rise, 
and will be in the 2500 to 3000 foot range by this afternoon.
Snow shower activity will focus across Mendocino, Lake, and southern 
Trinity Counties, with some additional light accumulations possible 
in areas of more persistent snow showers. Be prepared for locally
slippery road conditions over some of the highway passes in these
areas.


CAZ108-110-111-113>115-110000-
/O.EXP.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
/O.NEW.KEKA.WW.Y.0014.210310T1810Z-210311T0000Z/
Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake County-Southern Lake County-
1010 AM PST Wed Mar 10 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 4 PM PST THIS
AFTERNOON ABOVE 2500 FEET...
...PREVIOUS WINTER WEATHER ADVISORY DOWN TO 1500 FEET HAS 
EXPIRED...

* WHAT...Snow above 2500 feet. Additional snow accumulations of 1 to 
  3 inches possible, especially in more persistent snow shower 
  activity above 3000 feet.

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino Interior, 
  Northern Lake County and Southern Lake County Counties. This 
  includes South Fork Mountain on Highway 36, and additional 
  sections of Highways 36 and 3 in Trinity County above 2500 feet.

* WHEN...Until 4 PM PST this afternoon.

* IMPACTS...Plan on locally slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and allow extra time to reach your destination.

Check the latest road conditions at http://quickmap.dot.ca.gov or by 
calling 1-800-GAS- ROAD.

A Winter Weather Advisory for snow means that periods of snow will 
cause travel difficulties.

&&

$$

CAZ104>107-109-101915-
/O.EXP.KEKA.WW.Y.0013.000000T0000Z-210310T1800Z/
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Mendocino Coast-
1010 AM PST Wed Mar 10 2021

...WINTER WEATHER ADVISORY HAS EXPIRED...


$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 7, 2:04 PM PSTFrost AdvisoryEKAHumboldt, Mendocino17 hr
Mar 7, 2:04 PM PSTFreeze WarningEKALake, Mendocino17 hr

Nearby

Winter Weather Advisories in California, 2021Every winter weather 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.