Alert archive / California / Winter Weather Advisories in 2018

Winter Weather Advisory 2, NWS Eureka, CA

January 20, 2018Trinity County, California

NWS Eureka, CA issued this winter weather advisory at Jan 20, 2018, 1:47 PM PST for Trinity County, California. It took effect at Jan 21, 2018, 8:00 AM PST. It was in force for 14 hr.

The area

The counties it named.

The facts

Issued
Jan 20, 2018, 1:47 PM PST (21:47 UTC)
In effect from
Jan 21, 2018, 8:00 AM PST
Expired
Jan 21, 2018, 10:00 PM PST
In force
14 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 21:50 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, 9.8 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 2018-01-20Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 12:00Z on 2018-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 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
643 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this winter weather advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Eureka, CA wrote its last area forecast discussion before this winter weather advisory went out at Jan 19, 3:37 PM PST, 22 hours 10 minutes earlier.

Area forecast discussion, Jan 19, 3:37 PM PST, 22 hours 10 minutes before
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Hazardous weather outlook, Jan 19, 2:22 PM PST, 23 hours 25 minutes before
Hazardous Weather Outlook
National Weather Service Eureka CA
222 PM PST Fri Jan 19 2018

CAZ102-105-106-202230-
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-
222 PM PST Fri Jan 19 2018

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 7 PM PST THIS EVENING...

This hazardous weather outlook is for northwest California.

.DAY ONE...This afternoon and tonight.

A Winter Weather Advisory is currently in effect.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Additional high elevation snow will be possible on Sunday.

Strong southerly winds are expected on Sunday with gusts to 55 mph
expected on exposed ridges.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ107-108-202230-
Northern Trinity-Southern Trinity-
222 PM PST Fri Jan 19 2018

...WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGH SUNDAY
EVENING...

This hazardous weather outlook is for northwest California.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected through tonight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

A Winter Storm Watch is currently in effect for areas of 3,000 feet.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ101-103-104-109-202230-
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
222 PM PST Fri Jan 19 2018

This hazardous weather outlook is for northwest California.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected through tonight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Strong southerly winds are expected on Sunday with gusts to 45 mph
expected on exposed coastal areas.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ110>113-202230-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
222 PM PST Fri Jan 19 2018

This hazardous weather outlook is for northwest California.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 20, 2:45 AM PSTGale WarningEKA39 hr
Jan 20, 2:51 AM PSTWind AdvisoryEKADel Norte, Humboldt37 hr
Jan 20, 1:47 PM PSTWinter Storm WarningEKA32 hr

Nearby

Winter Weather Advisories in California, 2018Every winter weather advisory 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; radar from the NEXRAD Level II archive.