Alert archive / California / Frost Advisories in 2021
Frost Advisory 59, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at Dec 16, 2021, 4:21 AM PST for Del Norte County, Humboldt County, Mendocino County, California. It took effect at Dec 17, 2021, 12:00 AM PST. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- Dec 16, 2021, 4:21 AM PST (12:21 UTC)
- In effect from
- Dec 17, 2021, 12:00 AM PST
- Expired
- Dec 17, 2021, 9:00 AM PST
- In force
- 9 hr
- Issued by
- NWS Eureka, CA
Counties Del Norte County, CA, Humboldt County, CA, Mendocino County, CA
The radar
The Eureka (Bunker Hill) radar (KBHX), 47 km from the middle of the area, began a volume at 12:22 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, 0.4 hours before the alert went out and 210 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
- 682 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 83 m²/s²
- 0-3 km storm-relative helicity
- 219 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
070 WWUS76 KEKA 161221 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 421 AM PST Thu Dec 16 2021 CAZ101-103-109-162030- /O.NEW.KEKA.FR.Y.0059.211217T0800Z-211217T1700Z/ Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast- 421 AM PST Thu Dec 16 2021 ...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM PST FRIDAY... * WHAT...Temperatures as low as 32 will result in frost formation. * WHERE...Coastal Del Norte, Northern Humboldt Coast and Mendocino Coast Counties. * WHEN...From midnight tonight to 9 AM PST Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. * ADDITIONAL DETAILS...Dry air and clear skies will aid in cooling temperatures near the coast, which will lead to widespread frost. 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. && $$
1 follow-up statement
710 WWUS76 KEKA 162221 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 221 PM PST Thu Dec 16 2021 CAZ101-103-109-171700- /O.CON.KEKA.FR.Y.0059.211217T0800Z-211217T1700Z/ Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast- 221 PM PST Thu Dec 16 2021 ...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM PST FRIDAY... * WHAT...Temperatures as low as 29 will result in frost formation. * WHERE...Coastal Del Norte, Mendocino Coast and Northern Humboldt Coast Counties. * WHEN...From midnight tonight to 9 AM PST Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 15, 8:34 PM PST | Small Craft Advisory | EKA | 34 hr | |
| Dec 15, 10:09 PM PST | Winter Weather Advisory | EKA | Del Norte, Humboldt, Trinity | 8 hr |
| Dec 16, 5:15 AM PST | Small Craft Advisory | EKA | 25 hr | |
| Dec 16, 5:15 AM PST | Hazardous Seas Warning | EKA | 4 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.