Alert archive / California / Hard Freeze Warnings in 2021
Hard Freeze Warning 3, NWS Eureka, CA
NWS Eureka, CA issued this hard freeze warning at Mar 20, 2021, 2:30 PM PDT for Lake County, Mendocino County, California. It took effect at Mar 21, 2021, 12:00 AM PDT. It was in force for 8 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Mar 20, 2021, 2:30 PM PDT (21:30 UTC)
- In effect from
- Mar 21, 2021, 12:00 AM PDT
- Expired
- Mar 21, 2021, 8:00 AM PDT
- In force
- 8 hr
- Issued by
- NWS Eureka, CA
Counties Lake County, CA, Mendocino County, CA
The radar
The Beale AFB radar (KBBX), 128 km from the middle of the area, began a volume at 21:30 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, 9.5 hours before the alert went out and 188 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
- 8 J/kg
- Mixed-layer CIN
- -43 J/kg
- Mixed-layer LCL
- 1025 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- -36 m²/s²
- 0-3 km storm-relative helicity
- 42 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
680 WWUS76 KEKA 202130 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 230 PM PDT Sat Mar 20 2021 CAZ111-114-210530- /O.NEW.KEKA.HZ.W.0003.210321T0700Z-210321T1500Z/ Northeastern Mendocino Interior-Northern Lake- 230 PM PDT Sat Mar 20 2021 ...HARD FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM PDT SUNDAY... * WHAT...Sub-freezing temperatures as low as 26 expected. * WHERE...Northeastern Mendocino Interior and Northern Lake Counties. * WHEN...From midnight tonight to 8 AM PDT Sunday. * IMPACTS...Frost and freeze conditions will kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. To prevent freezing and possible bursting of outdoor water pipes they should be wrapped, drained, or allowed to drip slowly. Those that have in-ground sprinkler systems should drain them and cover above- ground pipes to protect them from freezing. 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. && $$ CAZ110-112-113-115-210530- /O.NEW.KEKA.FZ.W.0012.210321T0700Z-210321T1500Z/ Northwestern Mendocino Interior-Southwestern Mendocino Interior- Southeastern Mendocino Interior-Southern Lake- 230 PM PDT Sat Mar 20 2021 ...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM PDT SUNDAY... * WHAT...Widespread frost is expected tonight while sub-freezing temperatures develop in the coldest valleys, where temperatures as low as 29 are possible. * WHERE...Northwestern Mendocino Interior, Southwestern Mendocino Interior, Southeastern Mendocino Interior and Southern Lake Counties. * WHEN...From midnight tonight to 8 AM PDT Sunday. * IMPACTS...Frost and freeze conditions will kill crops and other sensitive vegetation. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Provide adequate shelter for outdoor pets or consider bringing them indoors. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$ CAZ101-103-210530- /O.NEW.KEKA.FR.Y.0013.210321T0700Z-210321T1500Z/ Coastal Del Norte-Northern Humboldt Coast- 230 PM PDT Sat Mar 20 2021 ...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM PDT SUNDAY... * WHAT...Temperatures as low as 34 will result in frost formation in protected coastal valleys. * WHERE...Coastal Del Norte and Northern Humboldt Coast Counties. * WHEN...From midnight tonight to 8 AM PDT Sunday. * 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. && $$
1 follow-up statement
024 WWUS76 KEKA 210510 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 1010 PM PDT Sat Mar 20 2021 CAZ111-114-211500- /O.CON.KEKA.HZ.W.0003.210321T0700Z-210321T1500Z/ Northeastern Mendocino Interior-Northern Lake- 1010 PM PDT Sat Mar 20 2021 ...HARD FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM PDT SUNDAY... * WHAT...Sub-freezing temperatures as low as 27 expected. * WHERE...Northeastern Mendocino Interior and Northern Lake County. * WHEN...From midnight tonight to 8 AM PDT Sunday. * IMPACTS...Frost and freeze conditions will kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. To prevent freezing and possible bursting of outdoor water pipes they should be wrapped, drained, or allowed to drip slowly. Those that have in-ground sprinkler systems should drain them and cover above- ground pipes to protect them from freezing. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$ CAZ110-112-113-115-211500- /O.CON.KEKA.FZ.W.0012.210321T0700Z-210321T1500Z/ Northwestern Mendocino Interior-Southwestern Mendocino Interior- Southeastern Mendocino Interior-Southern Lake- 1010 PM PDT Sat Mar 20 2021 ...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM PDT SUNDAY... * WHAT...Widespread frost is expected tonight while sub-freezing temperatures develop in the coldest valleys, where temperatures as low as 29 are possible. * WHERE...Northwestern Mendocino Interior, Southwestern Mendocino Interior, Southeastern Mendocino Interior and Southern Lake County. * WHEN...From midnight tonight to 8 AM PDT Sunday. * IMPACTS...Frost and freeze conditions will kill crops and other sensitive vegetation. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Provide adequate shelter for outdoor pets or consider bringing them indoors. 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. && $$ CAZ101-103-211500- /O.CON.KEKA.FR.Y.0013.210321T0700Z-210321T1500Z/ Coastal Del Norte-Northern Humboldt Coast- 1010 PM PDT Sat Mar 20 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT SUNDAY... * WHAT...Temperatures as low as 34 will result in frost formation in protected coastal valleys. * WHERE...Coastal Del Norte and Northern Humboldt Coast. * WHEN...From midnight tonight to 8 AM PDT Sunday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 20, 1:57 PM PDT | Small Craft Advisory | EKA | 37 hr | |
| Mar 20, 2:30 PM PDT | Frost Advisory | EKA | Del Norte, Humboldt | 18 hr |
| Mar 20, 2:30 PM PDT | Freeze Warning | EKA | Mendocino | 18 hr |
Nearby
Hard Freeze Warnings in California, 2021Every hard freeze warning 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.