Alert archive / California / Frost Advisories in 2021
Frost Advisory 38, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at May 21, 2021, 2:22 PM PDT for 4 counties in California. It took effect at May 22, 2021, 12:00 AM PDT. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- May 21, 2021, 2:22 PM PDT (21:22 UTC)
- In effect from
- May 22, 2021, 12:00 AM PDT
- Expired
- May 22, 2021, 9:00 AM PDT
- In force
- 9 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 21:26 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, 9.4 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1732 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 65 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
026 WWUS76 KEKA 212122 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 222 PM PDT Fri May 21 2021 CAZ106>108-110-111-114-220530- /O.NEW.KEKA.FR.Y.0038.210522T0700Z-210522T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 222 PM PDT Fri May 21 2021 ...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM SATURDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Humboldt Interior, Northern Trinity, Southern Trinity, Northwestern Mendocino Interior, Northeastern Mendocino Interior and Northern Lake Counties. * WHEN...From midnight tonight to 9 AM Saturday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. $$
2 follow-up statements
342 WWUS76 KEKA 220456 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 956 PM PDT Fri May 21 2021 CAZ106>108-110-111-114-221300- /O.CON.KEKA.FR.Y.0038.210522T0700Z-210522T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 956 PM PDT Fri May 21 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT SATURDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Trinity, Northwestern Mendocino Interior, Northeastern Mendocino Interior, Northern Trinity, Southern Humboldt Interior and Northern Lake Counties. * WHEN...Until 9 AM PDT Saturday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
197 WWUS76 KEKA 221032 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 332 AM PDT Sat May 22 2021 CAZ106>108-110-111-114-221600- /O.CON.KEKA.FR.Y.0038.000000T0000Z-210522T1600Z/ Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 332 AM PDT Sat May 22 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT THIS MORNING... * WHAT...Temperatures as low as 36 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 Saturday. * 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 |
|---|---|---|---|---|
| May 20, 8:09 PM PDT | Gale Warning | EKA | 25 hr | |
| May 20, 8:09 PM PDT | Small Craft Advisory | EKA | 15 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.