Alert archive / California / Winter Storm Warnings in 2018

Winter Storm Warning 4, NWS Eureka, CA

March 23, 2018Mendocino County, Trinity County, California

NWS Eureka, CA issued this winter storm warning at Mar 23, 2018, 3:40 AM PDT for Mendocino County, Trinity County, California. It took effect at Mar 23, 2018, 10:00 AM PDT. It was in force for 5 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
Mar 23, 2018, 3:40 AM PDT (10:40 UTC)
In effect from
Mar 23, 2018, 10:00 AM PDT
Expired
Mar 23, 2018, 2:33 PM PDT
In force
5 hr
Issued by
NWS Eureka, CA

Counties Mendocino County, CA, Trinity County, CA

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 00:00Z, 10.7 hours before the alert went out and 262 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 00:00Z on 2018-03-23Temperature 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 00:00Z on 2018-03-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
1773 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

067 
WWUS46 KEKA 231040
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
340 AM PDT Fri Mar 23 2018


CAZ107-108-111-232100-
/O.CAN.KEKA.WS.W.0003.000000T0000Z-180324T0600Z/
/O.NEW.KEKA.WS.W.0004.180323T1700Z-180324T0600Z/
Northern Trinity-Southern Trinity-Northeastern Mendocino Interior-
340 AM PDT Fri Mar 23 2018

...WINTER STORM WARNING IN EFFECT FROM 10 AM THIS MORNING TO
11 PM PDT THIS EVENING ABOVE 2000 FEET...

* WHAT...Heavy snow expected. Plan on difficult travel 
  conditions, including during the evening commute. Total snow 
  accumulations of 2 to 5 inches, with localized amounts up to 
  15 inches, are expected.

* WHERE...Northern Trinity, Southern Trinity and Northeastern
  Mendocino County Interior. Highways impacted include 299, 3 and
  36. 

* WHEN...Late this morning through this evening. Snowfall rates
  will increase during the day and peak by this evening. Snow 
  levels will rise to 3000 feet this afternoon. Additional snow is
  expected on Saturday.
  

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. If driving, slow down. Allow extra time and be
prepared for changing conditions. Check the latest forecasts and
call 1-800-427-7623 for current road conditions and chain
requirements before traveling. Be alert for rock slides in 
mountainous terrain.

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$

CAZ102-105-106-232100-
/O.CON.KEKA.WS.W.0003.000000T0000Z-180324T0600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-
340 AM PDT Fri Mar 23 2018

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 2000 FEET...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions, including during the evening commute. Additional
  snow accumulations of 6 to 8 inches, with localized amounts up 
  to 18 inches, are expected.

* WHERE...Del Norte Interior, Northern Humboldt Interior and
  Southern Humboldt County Interior. Highways impacted include
  299, 36 and 199.

* WHEN...This morning through this evening. Snowfall rates will
  increase during the day and peak by this evening. Snow levels
  will rise to 3000 feet this afternoon. Additional snow is
  expected on Saturday. 

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. If driving, slow down. Allow extra time and be
prepared for changing conditions. Check the latest forecasts and
call 1-800-427-7623 for current road conditions and chain
requirements before traveling. Be alert for rock slides in 
mountainous terrain.

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$
3 follow-up statements
284 
WWUS46 KEKA 231534
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
834 AM PDT Fri Mar 23 2018

CAZ102-105-106-231645-
/O.CAN.KEKA.WS.W.0003.000000T0000Z-180324T0600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-
834 AM PDT Fri Mar 23 2018

...WINTER STORM WARNING IS CANCELLED...

$$

CAZ111-231645-
/O.CAN.KEKA.WS.W.0004.180323T1700Z-180324T0600Z/
Northeastern Mendocino Interior-
834 AM PDT Fri Mar 23 2018

...WINTER STORM WARNING IS CANCELLED...

$$

CAZ107-108-232345-
/O.CON.KEKA.WS.W.0004.180323T1700Z-180324T0600Z/
Northern Trinity-Southern Trinity-
834 AM PDT Fri Mar 23 2018

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 2000 FEET...

* WHAT...Heavy snow expected. Plan on difficult travel 
  conditions, including during the evening commute. Total snow 
  accumulations of 2 to 5 inches, with localized amounts up to 
  12 inches, are expected.

* WHERE...Trinity County. Highways impacted include Hwy 299, 3,
  and 36.

* WHEN...10 AM to 11 PM today.

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. If driving, slow down. Allow extra time and be
prepared for changing conditions. Check the latest forecasts and
call 1-800-427-7623 for current road conditions and chain
requirements before travelling. Be alert for rock slides in
mountainous terrain.

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$
697 
WWUS46 KEKA 231751
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1051 AM PDT Fri Mar 23 2018

CAZ107-108-240200-
/O.CON.KEKA.WS.W.0004.000000T0000Z-180324T0600Z/
Northern Trinity-Southern Trinity-
1051 AM PDT Fri Mar 23 2018

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 2000 FEET...

* WHAT...Heavy snow expected. Plan on difficult travel conditions,
  including during the evening commute. Total snow accumulations
  near 5 inches, with localized amounts up to 12 inches, are 
  expected.

* WHERE...Trinity County. Highways impacted include Hwy 299, 3,
  and 36.

* WHEN...10 AM to 11 PM today.

* ADDITIONAL DETAILS...Slow down, allow extra time and be prepared
  for changing conditions. Check the latest forecasts and call
  1-800-427-7623 for current road conditions and chain
  requirements before traveling. Be alert for rock slides in
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. If driving, slow down. Allow extra time and be
prepared for changing conditions. Check the latest forecasts and
call 1-800-427-7623 for current road conditions and chain
requirements before travelling. Be alert for rock slides in
mountainous terrain.

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$

CAZ102-105-106-240200-
/O.NEW.KEKA.WW.Y.0010.180324T0000Z-180324T0900Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-
1051 AM PDT Fri Mar 23 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
2 AM PDT SATURDAY ABOVE 2500 FEET...

* WHAT...Snow expected. Plan on slippery road conditions, 
  including during the evening commute. Total snow accumulations 
  of 2 to 4 inches, with localized amounts up to 7 inches, are 
  expected.

* WHERE...Del Norte Interior, Northern Humboldt Interior and
  Southern Humboldt County Interior. Highways impacted include Hwy
  299, 199, and 36.

* WHEN...5 PM today to 2 AM Saturday.

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving. 

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$
372 
WWUS46 KEKA 232133
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
233 PM PDT Fri Mar 23 2018

CAZ107-108-240545-
/O.CAN.KEKA.WS.W.0004.000000T0000Z-180324T0600Z/
/O.NEW.KEKA.WS.A.0005.180324T1800Z-180325T1200Z/
/O.EXB.KEKA.WW.Y.0010.180324T0000Z-180324T1200Z/
Northern Trinity-Southern Trinity-
233 PM PDT Fri Mar 23 2018

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM PDT SATURDAY
ABOVE 2000 FEET...
...WINTER STORM WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
LATE SATURDAY NIGHT ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Plan on slippery road
  conditions. Above 2000 feet, total snow accumulations of 2 to 4
  inches during Friday night, with localized amounts up to 8 
  inches, are expected. Additional snow accumulations from 5 to 8 
  inches will be possible during Saturday.

* WHERE...Trinity County. Highways impacted include Hwy 299, 36,
  and 3.

* WHEN...For the Winter Weather Advisory, 5 PM today to 5 AM 
  Saturday. For the Winter Storm Watch, from Saturday morning 
  through late Saturday night.

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain. Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1- 800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving. 

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$

CAZ102-105-106-240545-
/O.NEW.KEKA.WS.A.0005.180324T1800Z-180325T1200Z/
/O.EXT.KEKA.WW.Y.0010.180324T0000Z-180324T1200Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-
233 PM PDT Fri Mar 23 2018

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 5 AM PDT SATURDAY
ABOVE 2000 FEET...
...WINTER STORM WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
LATE SATURDAY NIGHT ABOVE 2000 FEET...

* WHAT...Snow expected above 2000 feet. Plan on slippery road
  conditions. Above 2000 feet, total snow accumulations of 2 to 4
  inches during Friday night, with localized amounts up to 8 
  inches, are expected. Additional snow accumulations from 5 to 8 
  inches will be possible during Saturday.

* WHERE...Del Norte Interior, Northern Humboldt Interior and
  Southern Humboldt County Interior. Highways impacted include Hwy
  199, 299, 36, and 96.

* WHEN...For the Winter Weather Advisory, 5 PM today to 5 AM 
  Saturday. For the Winter Storm Watch, from Saturday morning 
  through late Saturday night.

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain. Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1- 800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving. 

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

For a detailed view of the hazard area visit:
http://www.wrh.noaa.gov/map/?wfo=eka

&&

$$

CAZ110-111-240545-
/O.NEW.KEKA.WS.A.0005.180324T1800Z-180325T1200Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
233 PM PDT Fri Mar 23 2018

...WINTER STORM WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
LATE SATURDAY NIGHT ABOVE 2000 FEET...

* WHAT...Heavy snow possible. Plan on difficult travel conditions.
  Total snow accumulations of 5 to 8 inches possible during
  Saturday.

* WHERE...Northwestern Mendocino Interior and Northeastern
  Mendocino County Interior.

* WHEN...From Saturday morning through late Saturday night.

* ADDITIONAL DETAILS...Slow down, allow extra time and be 
  prepared for changing conditions. Check the latest forecasts 
  and call 1-800-427-7623 for current road conditions and chain 
  requirements before traveling. Be alert for rock slides in 
  mountainous terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow, sleet or ice accumulations that may impact travel. Continue
to monitor the latest forecasts.

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 23, 5:39 AM PDTSpecial Weather StatementEKADel Norte36 min
Mar 23, 10:51 AM PDTWinter Weather AdvisoryEKADel Norte, Humboldt, Trinity18 hr
Mar 23, 2:33 PM PDTWinter Storm WatchEKADel Norte, Humboldt, Mendocino, Trinity13 hr

Nearby

Winter Storm Warnings in California, 2018Every winter storm warning in 2018

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.