Alert archive / California / Winter Storm Warnings in 2020

Winter Storm Warning 4, NWS Eureka, CA

April 3, 2020Trinity County, California

NWS Eureka, CA issued this winter storm warning at Apr 3, 2020, 2:22 PM PDT for Trinity County, California. It took effect at Apr 4, 2020, 5:00 AM PDT. It was in force for 45 hr. 6 reports 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
Apr 3, 2020, 2:22 PM PDT (21:22 UTC)
In effect from
Apr 4, 2020, 5:00 AM PDT
Expired
Apr 6, 2020, 2:00 AM PDT
In force
45 hr
Issued by
NWS Eureka, CA

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 101 km from the middle of the area, began a volume at 21:21 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
Apr 4, 11:50 AM PDTSNOW 11 Sw Trinity Center, CASNOW BEGAN AROUND 0700 AND ACCUMULATING. SNOW IS INCREASING IN INTENSITY. SPOTTER OBSERVED ACCUMULATION ON ROADWAYS, BEGINNING AROUND 1030.
Apr 4, 12:30 PM PDTSNOW 0.8Lewiston, CASOCIAL MEDIA REPORT OF LESS THAN AN INCH OF SNOW FELL FROM 11 A.M. TO 12:30 P.M. IN LEWISTON AT AN ELEVATION OF 2,300 FEET.
Apr 4, 1:10 PM PDTSNOW 21 Nne Carrville, CASOCIAL MEDIA REPORT OF 2 INCHES FELL FROM 9:30 A.M. TO 1:10 P.M. AT AN ELEVATION BETWEEN 2,500 TO 2,800 FEET NEAR COFFEE CREEK.
Apr 4, 2:12 PM PDTSNOW 319 Ne Covelo, CASOCIAL MEDIA REPORT OF 3 INCHES OF SNOW FROM 8:30 A.M. TO 2 P.M. AT AN ELEVATION OF 2,200 FEET.
Apr 4, 3:30 PM PDTSNOW 21 S Trinity Center, CABEGUN AT 8 AM PDT.
Apr 5, 11:25 PM PDTSNOW 21 Sw Trinity Center, CATWO INCHES OF FRESH SNOW ON THE SNOWBOARD THAT FELL IN THE EVENING. ELEVATION IS 2500 FEET.

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 12:00Z, 9.4 hours before the alert went out and 193 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 2020-04-03Temperature 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 2020-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
783 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

709 
WWUS46 KEKA 032122
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
222 PM PDT Fri Apr 3 2020


CAZ107-040530-
/O.UPG.KEKA.WS.A.0004.200404T1200Z-200405T1200Z/
/O.NEW.KEKA.WS.W.0004.200404T1200Z-200406T0600Z/
Northern Trinity-
222 PM PDT Fri Apr 3 2020

...WINTER STORM WARNING IN EFFECT FROM 5 AM SATURDAY TO 11 PM PDT
SUNDAY ABOVE 3500 FEET...

* WHAT...Heavy snow accumulations in excess of 7 inches expected 
  above 3500 feet.

* WHERE...Northern Trinity County.

* WHEN...From 5 AM Saturday to 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous at Scott Mountain
  Summit on Highway 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
11 follow-up statements
994 
WWUS46 KEKA 040517
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1017 PM PDT Fri Apr 3 2020

CAZ107-041200-
/O.CON.KEKA.WS.W.0004.200404T1200Z-200406T0600Z/
Northern Trinity-
1017 PM PDT Fri Apr 3 2020

...WINTER STORM WARNING REMAINS IN EFFECT FROM 5 AM SATURDAY TO
11 PM PDT SUNDAY ABOVE 3500 FEET...

* WHAT...Heavy snow accumulations in excess of 7 inches expected 
  above 3500 feet.

* WHERE...Northern Trinity County.

* WHEN...From 5 AM Saturday to 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous at Scott Mountain 
  Summit on Highway 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
925 
WWUS46 KEKA 041113
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
413 AM PDT Sat Apr 4 2020

...Snow levels will fluctuate as two systems move through the area...

.Cold air in northern Trinity county will keep snow levels around
3,000 to 3,5000 feet this morning. They will rise to around 4,000
feet this afternoon and evening. Sunday afternoon they will fall
to around 3,500 feet once again. 

CAZ107-041915-
/O.CON.KEKA.WS.W.0004.200404T1200Z-200406T0600Z/
Northern Trinity-
413 AM PDT Sat Apr 4 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT SUNDAY
ABOVE 3500 FEET...

* WHAT...Heavy snow is expected mainly above 3500 feet. Snow
  accumulations of 10 to 20 inches are possible above 4,500 feet
  with amounts of 7 to 10 inches above 3,500 feet. Local amounts 1
  to 3 inches are possible as low as 2,500 feet this morning. 

* WHERE...Northern Trinity County.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous on highway 3 north
  of Weaverville with the biggest impacts at Scott Mountain 
  Summit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
873 
WWUS46 KEKA 041750
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1050 AM PDT Sat Apr 4 2020


CAZ107-050200-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-
1050 AM PDT Sat Apr 4 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT SUNDAY
ABOVE 3000 FEET...

* WHAT...Heavy snow is expected for elevations above 3000 feet.
  Snow accumulations near 5 inches at 3000 feet, ranging to over a
  foot for elevations above 3500 feet.

* WHERE...Northern Trinity County, including Oregon Mountain on
  Highway 299, and Scott Mountain Summit on Highway 3.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous on highway 3 north 
  of Weaverville with the biggest impacts at Scott Mountain 
  Summit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
641 
WWUS46 KEKA 041830
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1130 AM PDT Sat Apr 4 2020


CAZ108-050230-
/O.EXA.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Southern Trinity-
1130 AM PDT Sat Apr 4 2020

...WINTER STORM WARNING IN EFFECT UNTIL 11 PM PDT SUNDAY ABOVE
3000 FEET...

* WHAT...Heavy snow accumulations near 7 inches above 3000 feet.

* WHERE...Southern Trinity County, including portions of Highway
  36.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous on highway 3 north
  of Weaverville with the biggest impacts at Scott Mountain
  Summit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$

CAZ107-050230-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-
1130 AM PDT Sat Apr 4 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT SUNDAY
ABOVE 3000 FEET...

* WHAT...Heavy snow is expected for elevations above 3000 feet. 
  Snow accumulations near 5 inches at 3000 feet, ranging to over 
  a foot for elevations above 3500 feet.

* WHERE...Northern Trinity County, including Oregon Mountain on 
  Highway 299, and Scott Mountain Summit on Highway 3.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous on highway 3 north 
  of Weaverville with the biggest impacts at Scott Mountain 
  Summit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
768 
WWUS46 KEKA 042118
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
218 PM PDT Sat Apr 4 2020


CAZ107-108-050530-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-Southern Trinity-
218 PM PDT Sat Apr 4 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT SUNDAY
ABOVE 3000 FEET...

* WHAT...Heavy snow accumulations near 5 inches for elevations
  near 3000 feet, and in excess of a foot for elevations above
  4000 feet.

* WHERE...Elevations above 3000 feet in Trinity County. Highway
  passes impacted include Scott Mountain Summit on highway 3,
  Oregon Mountain on highway 299, and portions of highways 36 and
  3 in southern Trinity County.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous. Travel may be
  impossible at Scott Mountain Summit on highway 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
107 
WWUS46 KEKA 050512
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1012 PM PDT Sat Apr 4 2020

CAZ107-108-051200-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-Southern Trinity-
1012 PM PDT Sat Apr 4 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT SUNDAY
ABOVE 3000 FEET...

* WHAT...Heavy snow accumulations near 5 inches for elevations 
  near 3,000 feet, and in excess of a foot for elevations above 
  4,000 feet.

* WHERE...Elevations above 3,000 feet in Trinity County. Highway 
  passes impacted include Scott Mountain Summit on Highway 3, 
  Oregon Mountain on Highway 299, and portions of Highways 36 
  and 3 in southern Trinity County.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Road conditions will be hazardous. Travel may be 
  impossible at Scott Mountain Summit on highway 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
572 
WWUS46 KEKA 051107
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
407 AM PDT Sun Apr 5 2020

...Snow continues at higher elevations...

.Snow levels are currently 3,500 to 4,000 feet in Trinity county.
Heavy snow is expected this morning. Showers will continue this
afternoon and tonight. Snow levels will gradually fall to 2,500
feet late tonight, but most accumulating snow will be above 3,500
feet. 

CAZ107-108-051915-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-Southern Trinity-
407 AM PDT Sun Apr 5 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 3500 FEET...

* WHAT...Heavy snow accumulations of 6 to 12 inches above 4,000
  feet today and 3 to 7 inches for elevations near 3,500 feet as
  snow levels fall this afternoon.

* WHERE...Trinity county above 4,000 feet today falling to 3,500
  feet late this afternoon and evening. This will impact highway 3
  at Scott mountain summit and hwy 36 at south fork mountain and 
  east of Hwy 3. 

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Road conditions will be hazardous. Travel may be 
  impossible at Scott Mountain Summit on highway 3.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
117 
WWUS46 KEKA 051723
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1023 AM PDT Sun Apr 5 2020


CAZ107-108-060130-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-Southern Trinity-
1023 AM PDT Sun Apr 5 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 3500 FEET...

* WHAT...Heavy snow accumulations of 6 to 12 inches above 4000
  feet today and 3 to 7 inches for elevations near 3500 feet.

* WHERE...Trinity county above 3500 4000 feet. Travel will be
  hazardous at Scott Mountain Summit on highway 3 in northern
  Trinity County, and along portions of highway 36 and highway 3 
  in southern Trinity County.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Road conditions will be hazardous. Travel may be 
  impossible at Scott Mountain Summit on highway 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
142 
WWUS46 KEKA 052111
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
211 PM PDT Sun Apr 5 2020


CAZ108-052215-
/O.CAN.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Southern Trinity-
211 PM PDT Sun Apr 5 2020

...WINTER STORM WARNING IS CANCELLED...

$$

CAZ107-060515-
/O.CON.KEKA.WS.W.0004.000000T0000Z-200406T0600Z/
Northern Trinity-
211 PM PDT Sun Apr 5 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 3500 FEET...

* WHAT...Heavy snow accumulations of 6 to 12 inches above 4500
  feet, and 3 to 7 inches for elevations near 3500 feet.

* WHERE...Trinity County above 3500 feet. Travel will be 
  hazardous at Scott Mountain Summit on highway 3 in northern 
  Trinity County.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Road conditions will be hazardous. Travel may be 
  impossible at Scott Mountain Summit on highway 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
561 
WWUS46 KEKA 060513
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
1013 PM PDT Sun Apr 5 2020

CAZ107-060900-
/O.EXT.KEKA.WS.W.0004.000000T0000Z-200406T0900Z/
Northern Trinity-
1013 PM PDT Sun Apr 5 2020

...WINTER STORM WARNING NOW IN EFFECT UNTIL 2 AM PDT MONDAY ABOVE
3500 FEET...

* WHAT...Additional snow accumulations of 2 to 4 inches are
  possible above 3500 feet, with light snow accumulations as low
  as 2500 feet as well.

* WHERE...Primarily across northeastern Trinity County, with
  heaviest accumulations above 3500 feet. Travel will be hazardous
  at Scott Mountain Summit and many other areas along Highway 3 
  in northern Trinity County.

* WHEN...Until 2 AM PDT Monday.

* IMPACTS...Road conditions will be hazardous. Travel may be
  impossible along Highway 3, particularly near Scott Mountain 
  Summit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. Prepare for possible power
outages. 

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

&&

$$
172 
WWUS46 KEKA 060905
WSWEKA

URGENT - WINTER WEATHER MESSAGE
National Weather Service Eureka CA
205 AM PDT Mon Apr 6 2020

CAZ107-061015-
/O.EXP.KEKA.WS.W.0004.000000T0000Z-200406T0900Z/
Northern Trinity-
205 AM PDT Mon Apr 6 2020

...WINTER STORM WARNING HAS EXPIRED...

A few snow showers may persist overnight, but accumulations are
expected to be less than an inch.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 3, 2:20 PM PDTSmall Craft AdvisoryEKA23 hr

Nearby

Winter Storm Warnings in California, 2020Every winter storm warning in 2020

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.