Alert archive / California / Frost Advisories in 2021
Frost Advisory 37, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at May 20, 2021, 2:09 PM PDT for 5 counties in California. It took effect at May 21, 2021, 1:00 AM PDT. It was in force for 8 hr.
The area
The counties it named.
The facts
- Issued
- May 20, 2021, 2:09 PM PDT (21:09 UTC)
- In effect from
- May 21, 2021, 1:00 AM PDT
- Expired
- May 21, 2021, 9:00 AM PDT
- In force
- 8 hr
- Issued by
- NWS Eureka, CA
Counties Del Norte County, CA, Humboldt County, CA, Lake County, CA, Mendocino County, CA, Trinity County, CA
The radar
The Eureka (Bunker Hill) radar (KBHX), 75 km from the middle of the area, began a volume at 21:08 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, 9.2 hours before the alert went out and 233 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
- 3 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 1016 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 100 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
352 WWUS76 KEKA 202109 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 209 PM PDT Thu May 20 2021 CAZ112-113-115-202215- /O.CAN.KEKA.WI.Y.0011.000000T0000Z-210521T0000Z/ Southwestern Mendocino Interior-Southeastern Mendocino Interior- Southern Lake- 209 PM PDT Thu May 20 2021 ...WIND ADVISORY IS CANCELLED... $$ CAZ102-105>108-110-111-210515- /O.NEW.KEKA.FR.Y.0037.210521T0800Z-210521T1600Z/ Del Norte Interior-Northern Humboldt Interior- Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- 209 PM PDT Thu May 20 2021 ...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM PDT FRIDAY... * WHAT...Temperatures as low as 29 will result in frost formation. * WHERE...Del Norte Interior, Northern Humboldt Interior, Southern Humboldt Interior, Northern Trinity, Southern Trinity, Northwestern Mendocino Interior and Northeastern Mendocino Interior Counties. * WHEN...From 1 AM to 9 AM PDT Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
3 follow-up statements
448 WWUS76 KEKA 202251 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 351 PM PDT Thu May 20 2021 CAZ114-210700- /O.EXA.KEKA.FR.Y.0037.210521T0800Z-210521T1600Z/ Northern Lake- 351 PM PDT Thu May 20 2021 ...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM PDT FRIDAY... * WHAT...Temperatures as low as 34 will result in frost formation. * WHERE...Northern Lake County. * WHEN...From 1 AM to 9 AM PDT 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. && $$ CAZ102-105>108-110-111-210700- /O.CON.KEKA.FR.Y.0037.210521T0800Z-210521T1600Z/ Del Norte Interior-Northern Humboldt Interior- Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- 351 PM PDT Thu May 20 2021 ...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM PDT FRIDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Trinity, Northeastern Mendocino Interior, Northwestern Mendocino Interior, Del Norte Interior, Northern Humboldt Interior, Northern Trinity and Southern Humboldt Interior Counties. * WHEN...From 1 AM to 9 AM PDT Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
086 WWUS76 KEKA 210553 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 1053 PM PDT Thu May 20 2021 CAZ102-105>108-110-111-114-211400- /O.CON.KEKA.FR.Y.0037.210521T0800Z-210521T1600Z/ Del Norte Interior-Northern Humboldt Interior- Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 1053 PM PDT Thu May 20 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT FRIDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Trinity, Northeastern Mendocino Interior, Northwestern Mendocino Interior, Del Norte Interior, Northern Humboldt Interior, Northern Trinity, Southern Humboldt Interior and Northern Lake Counties. * WHEN...Until 9 AM PDT 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. && $$
085 WWUS76 KEKA 211030 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 330 AM PDT Fri May 21 2021 CAZ102-105>108-110-111-114-211600- /O.CON.KEKA.FR.Y.0037.000000T0000Z-210521T1600Z/ Del Norte Interior-Northern Humboldt Interior- Southern Humboldt Interior-Northern Trinity-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake- 330 AM PDT Fri May 21 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT THIS MORNING... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Trinity, Northeastern Mendocino Interior, Northwestern Mendocino Interior, Del Norte Interior, Northern Humboldt Interior, Northern Trinity, Southern Humboldt Interior and Northern Lake Counties. * WHEN...Until 9 AM PDT Friday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 8:08 PM PDT | Gale Warning | EKA | 24 hr | |
| May 19, 8:08 PM PDT | Small Craft Advisory | EKA | 15 hr | |
| May 20, 3:35 AM PDT | Wind Advisory | EKA | Mendocino | 11 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.