Alert archive / California / Frost Advisories in 2025
Frost Advisory 21, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at Oct 5, 2025, 11:37 PM PDT for Trinity County, California. It took effect at Oct 6, 2025, 2:00 AM PDT. It was in force for 7 hr.
The area
The counties it named.
The facts
- Issued
- Oct 5, 2025, 11:37 PM PDT (06:37 UTC)
- In effect from
- Oct 6, 2025, 2:00 AM PDT
- Expired
- Oct 6, 2025, 9:00 AM PDT
- In force
- 7 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 06:34 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 00:00Z, 6.6 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2611 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
161 WWUS76 KEKA 060637 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 1137 PM PDT Sun Oct 5 2025 CAZ107-108-061445- /O.NEW.KEKA.FR.Y.0021.251006T0900Z-251006T1600Z/ Northern Trinity-Southern Trinity- Including Hayfork, Big Bar, Ruth, Weaverville, Carrville, Douglas City, Del Loma, Junction City, and Trinity Center 1137 PM PDT Sun Oct 5 2025 ...FROST ADVISORY IN EFFECT UNTIL 9 AM PDT MONDAY... * WHAT...Temperatures as low as 40 will result in frost formation. * WHERE...Trinity County. * WHEN...Until 9 AM PDT Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka MKK
2 follow-up statements
681 WWUS76 KEKA 061238 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 538 AM PDT Mon Oct 6 2025 CAZ107-108-061600- /O.CON.KEKA.FR.Y.0021.000000T0000Z-251006T1600Z/ Northern Trinity-Southern Trinity- Including Hayfork, Ruth, Weaverville, Carrville, Douglas City, Junction City, and Trinity Center 538 AM PDT Mon Oct 6 2025 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT THIS MORNING... * WHAT...Temperatures as low as 35 will result in frost formation. * WHERE...Trinity County. * WHEN...Until 9 AM PDT this morning. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. * ADDITIONAL DETAILS...The coldest valleys will see a brief period of frost this morning. Ridges will remain significantly warmer. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka MKK
329 WWUS76 KEKA 061617 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 917 AM PDT Mon Oct 6 2025 CAZ107-108-061730- /O.EXP.KEKA.FR.Y.0021.000000T0000Z-251006T1600Z/ Northern Trinity-Southern Trinity- Including Ruth, Douglas City, Hayfork, Trinity Center, Carrville, Weaverville, and Junction City 917 AM PDT Mon Oct 6 2025 ...FROST ADVISORY HAS EXPIRED... $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka JJW
The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 6, 10:38 AM PDT | Small Craft Advisory | EKA | 3 hr |
Nearby
Frost Advisories in California, 2025Every frost advisory in 2025
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.