Alert archive / California / Winter Storm Warnings in 2018

Winter Storm Warning 3, NWS Eureka, CA

March 22, 20184 counties in California

NWS Eureka, CA issued this winter storm warning at Mar 22, 2018, 3:28 AM PDT for 4 counties in California. It took effect at Mar 22, 2018, 11:00 PM PDT. It was in force for 10 hr. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Mar 22, 2018, 3:28 AM PDT (10:28 UTC)
In effect from
Mar 22, 2018, 11:00 PM PDT
Expired
Mar 23, 2018, 8:34 AM PDT
In force
10 hr
Issued by
NWS Eureka, CA

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

The radar

The Eureka (Bunker Hill) radar (KBHX), 60 km from the middle of the area, began a volume at 10:28 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.

What was reported inside it

TimeReportWhereRemark
Mar 23, 8:10 AM PDTSNOW 17 E Bridgville, CA2800 FEET WITH 36 DEGREES. SNOW STARTED AT 1 AT 3 AM WITH 1 INCH ON GROUND. MODERATE FLAKES FALLING CURRENTLY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 00:00Z, 10.5 hours before the alert went out and 204 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 2018-03-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 00:00Z on 2018-03-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.1939587897117136156Sfc1 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
3 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
1510 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
278 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

318 
WWUS46 KEKA 221028
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
328 AM PDT Thu Mar 22 2018

CAZ102-105>108-111-222330-
/O.UPG.KEKA.WS.A.0004.180323T0600Z-180324T0600Z/
/O.NEW.KEKA.WS.W.0003.180323T0600Z-180324T0600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northeastern Mendocino Interior-
328 AM PDT Thu Mar 22 2018

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

* WHAT...Heavy snow expected. Plan on difficult travel conditions,
  including during the evening commute on Friday. Total snow
  accumulations of 4 to 8 inches, with localized amounts up to 18
  inches above 3000 feet, are expected.

* WHERE...Del Norte Interior, Interior Humboldt County, Northern
  Trinity, Southern Trinity and Northeastern Mendocino Interior
  County. Highways impacted include 199 near the Oregon border,
  299 at Berry Summit, 299 at Oregon Mountain, 299 at Buckhorn 
  Summit and portions of 3 and 36 above 2000 feet.

* WHEN...Late this evening through Friday evening. Snowfall rates
  will increase during the day on Friday. Snow levels will slowly
  rise to 3000 feet Friday afternoon.

* 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

&&

$$
4 follow-up statements
333 
WWUS46 KEKA 222057
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
157 PM PDT Thu Mar 22 2018

CAZ102-105>108-111-230500-
/O.CON.KEKA.WS.W.0003.180323T0600Z-180324T0600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northeastern Mendocino Interior-
157 PM PDT Thu Mar 22 2018

...WINTER STORM WARNING REMAINS IN EFFECT FROM 11 PM THIS EVENING
TO 11 PM PDT FRIDAY ABOVE 2000 FEET...

* WHAT...Heavy snow expected. Plan on difficult travel conditions,
  including during the evening commute on Friday. Total snow
  accumulations of 4 to 8 inches, with localized amounts up to 18
  inches above 3000 feet, are expected.

* WHERE...Del Norte Interior, Interior Humboldt County, Northern
  Trinity, Southern Trinity and Northeastern Mendocino Interior
  County. Highways impacted include 199 near the Oregon border,
  299 at Berry Summit, 299 at Oregon Mountain, 299 at Buckhorn 
  Summit and portions of 3 and 36 above 2000 feet.

* WHEN...Late this evening through Friday evening. Snowfall rates
  will increase during the day on Friday. Snow levels will slowly
  rise to 3000 feet Friday afternoon.

* 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

&&

$$
925 
WWUS46 KEKA 230448
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
948 PM PDT Thu Mar 22 2018

CAZ102-105>108-111-231300-
/O.CON.KEKA.WS.W.0003.180323T0600Z-180324T0600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northeastern Mendocino Interior-
948 PM PDT Thu Mar 22 2018

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

* WHAT...Heavy snow expected. Plan on difficult travel conditions,
  including during the evening commute on Friday. Total snow
  accumulations of 4 to 8 inches, with localized amounts up to 18
  inches above 3000 feet, are expected.

* WHERE...Del Norte Interior, Interior Humboldt County, Northern
  Trinity, Southern Trinity and Northeastern Mendocino Interior
  County. Highways impacted include 199 near the Oregon border,
  299 at Berry Summit, 299 at Oregon Mountain, 299 at Buckhorn 
  Summit and portions of 3 and 36 above 2000 feet.

* WHEN...Late this evening through Friday evening. Snowfall rates
  will increase during the day on Friday. Snow levels will slowly
  rise to 3000 feet Friday afternoon. Additional snow is expected
  Saturday as well. 

* 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

&&

$$
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

&&

$$
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

&&

$$

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.