Alert archive / California / Frost Advisories in 2021
Frost Advisory 44, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at Oct 7, 2021, 1:25 PM PDT for 4 counties in California. It took effect at Oct 8, 2021, 1:00 AM PDT. It was in force for 7 hr.
The area
The counties it named.
The facts
- Issued
- Oct 7, 2021, 1:25 PM PDT (20:25 UTC)
- In effect from
- Oct 8, 2021, 1:00 AM PDT
- Expired
- Oct 8, 2021, 8:15 AM PDT
- In force
- 7 hr
- Issued by
- NWS Eureka, CA
Counties Humboldt County, CA, Lake County, CA, Mendocino County, CA, Trinity County, CA
The radar
The Eureka (Bunker Hill) radar (KBHX), 102 km from the middle of the area, began a volume at 20:26 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
Oakland, CA (KOAK), launched 12:00Z, 8.4 hours before the alert went out and 267 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
- 1 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 714 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 68 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
057 WWUS76 KEKA 072025 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 125 PM PDT Thu Oct 7 2021 CAZ106>108-110-111-114-080430- /O.NEW.KEKA.FR.Y.0044.211008T0800Z-211008T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 125 PM PDT Thu Oct 7 2021 ...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM PDT FRIDAY... * WHAT...Temperatures in the low to mid 30s will result in frost formation. * WHERE...Sheltered valleys in portions of Southern Humboldt Interior, Northern Trinity, Southern Trinity, Northwestern Mendocino Interior, Northeastern Mendocino Interior and Northern Lake Counties. * WHEN...From 1 AM to 9 AM PDT Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. * ADDITIONAL DETAILS...Frost will be likely once again on Saturday morning in similar locations. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
3 follow-up statements
366 WWUS76 KEKA 080359 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 859 PM PDT Thu Oct 7 2021 CAZ106>108-110-111-114-081200- /O.CON.KEKA.FR.Y.0044.211008T0800Z-211008T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 859 PM PDT Thu Oct 7 2021 ...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM PDT FRIDAY... * WHAT...Temperatures in the low to mid 30s will result in frost formation. * WHERE...Sheltered valleys in portions of Southern Humboldt Interior, Trinity, Northwestern Mendocino Interior, Northeastern Mendocino Interior and Northern Lake Counties. * WHEN...From 1 AM to 9 AM PDT Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. * ADDITIONAL DETAILS...Frost will be likely once again on Saturday morning in similar locations. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
129 WWUS76 KEKA 081014 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 314 AM PDT Fri Oct 8 2021 CAZ106>108-110-111-114-081600- /O.CON.KEKA.FR.Y.0044.000000T0000Z-211008T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 314 AM PDT Fri Oct 8 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT THIS MORNING... * WHAT...Temperatures as low as 100 below will result in frost formation. * WHERE...Southern Trinity, Northwestern Mendocino Interior, Northeastern Mendocino Interior, Northern Trinity, Southern Humboldt Interior and Northern Lake Counties. * WHEN...Until 9 AM PDT this morning. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
364 WWUS76 KEKA 081515 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 815 AM PDT Fri Oct 8 2021 CAZ106>108-110-111-114-081615- /O.CAN.KEKA.FR.Y.0044.000000T0000Z-211008T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 815 AM PDT Fri Oct 8 2021 ...FROST ADVISORY IS CANCELLED... A couple selects spots like Hayfork managed to reach the mid 30s, otherwise clouds kept most of the area milder overnight, limiting frost, and temperatures will continue to rise with daytime heating this morning. $$
The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 7, 2:56 PM PDT | Fire Weather Watch | EKA | 60 hr |
Nearby
Frost Advisories in California, 2021Every frost advisory in 2021
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.