Alert archive / California / Frost Advisories in 2021
Frost Advisory 55, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at Nov 25, 2021, 1:21 PM PST for Humboldt County, Mendocino County, California. It took effect at Nov 26, 2021, 3:00 AM PST. It was in force for 6 hr.
The area
The counties it named.
The facts
- Issued
- Nov 25, 2021, 1:21 PM PST (21:21 UTC)
- In effect from
- Nov 26, 2021, 3:00 AM PST
- Expired
- Nov 26, 2021, 9:00 AM PST
- In force
- 6 hr
- Issued by
- NWS Eureka, CA
Counties Humboldt County, CA, Mendocino County, CA
The radar
The Eureka (Bunker Hill) radar (KBHX), 71 km from the middle of the area, began a volume at 21:22 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, 9.4 hours before the alert went out and 266 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
- 1666 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 1 m²/s²
- 0-3 km storm-relative helicity
- 45 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
581 WWUS76 KEKA 252121 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 121 PM PST Thu Nov 25 2021 CAZ106-109-112-113-260530- /O.NEW.KEKA.FR.Y.0055.211126T1100Z-211126T1700Z/ Southern Humboldt Interior-Mendocino Coast- Southwestern Mendocino Interior-Southeastern Mendocino Interior- 121 PM PST Thu Nov 25 2021 ...FROST ADVISORY IN EFFECT FROM 3 AM TO 9 AM PST FRIDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Humboldt Interior, Mendocino Coast, Southwestern Mendocino Interior and Southeastern Mendocino Interior Counties. * WHEN...From 3 AM to 9 AM PST Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. * ADDITIONAL DETAILS...Low temperatures in interior valleys is expected overnight. Light winds and strong valley inversions are expected. Lingering midlevel clouds could keep northern areas bit warmer. 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. && $$
3 follow-up statements
018 WWUS76 KEKA 260519 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 919 PM PST Thu Nov 25 2021 CAZ106-109-112-113-261330- /O.CON.KEKA.FR.Y.0055.211126T1100Z-211126T1700Z/ Southern Humboldt Interior-Mendocino Coast- Southwestern Mendocino Interior-Southeastern Mendocino Interior- 919 PM PST Thu Nov 25 2021 ...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM PST FRIDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Mendocino Coast, Southwestern Mendocino Interior, Southern Humboldt Interior and Southeastern Mendocino Interior Counties. * WHEN...From 3 AM to 9 AM PST Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
938 WWUS76 KEKA 261322 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 522 AM PST Fri Nov 26 2021 CAZ106-109-112-113-261700- /O.CON.KEKA.FR.Y.0055.000000T0000Z-211126T1700Z/ Southern Humboldt Interior-Mendocino Coast- Southwestern Mendocino Interior-Southeastern Mendocino Interior- 522 AM PST Fri Nov 26 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PST THIS MORNING... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Mendocino Coast, Southwestern Mendocino Interior, Southern Humboldt Interior and Southeastern Mendocino Interior Counties. * WHEN...Until 9 AM PST 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. && $$
907 WWUS76 KEKA 261647 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 847 AM PST Fri Nov 26 2021 CAZ106-109-112-113-261800- /O.EXP.KEKA.FR.Y.0055.000000T0000Z-211126T1700Z/ Southern Humboldt Interior-Mendocino Coast- Southwestern Mendocino Interior-Southeastern Mendocino Interior- 847 AM PST Fri Nov 26 2021 ...FROST ADVISORY WILL EXPIRE AT 9 AM PST THIS MORNING... $$
The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 25, 3:04 AM PST | Frost Advisory | EKA | Humboldt, Mendocino | 6 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.