Alert archive / California / Frost Advisories in 2021
Frost Advisory 43, NWS Eureka, CA
NWS Eureka, CA issued this frost advisory at Sep 28, 2021, 1:04 PM PDT for Humboldt County, Mendocino County, Trinity County, California. It took effect at Sep 29, 2021, 12:00 AM PDT. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- Sep 28, 2021, 1:04 PM PDT (20:04 UTC)
- In effect from
- Sep 29, 2021, 12:00 AM PDT
- Expired
- Sep 29, 2021, 9:00 AM PDT
- In force
- 9 hr
- Issued by
- NWS Eureka, CA
Counties Humboldt County, CA, Mendocino County, CA, Trinity County, CA
The radar
The Eureka (Bunker Hill) radar (KBHX), 73 km from the middle of the area, began a volume at 20:09 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, 8.1 hours before the alert went out and 241 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
- 940 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 90 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
946 WWUS76 KEKA 282004 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 104 PM PDT Tue Sep 28 2021 CAZ106-108-110-111-290515- /O.NEW.KEKA.FR.Y.0043.210929T0700Z-210929T1600Z/ Southern Humboldt Interior-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- 104 PM PDT Tue Sep 28 2021 ...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM WEDNESDAY... * WHAT...Temperatures as low as 34 will result in frost formation. * WHERE...Southern Humboldt Interior, Southern Trinity, Northwestern Mendocino Interior, and Northeastern Mendocino Interior. * WHEN...From midnight tonight to 9 AM Wednesday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. * ADDITIONAL DETAILS...Normally colder areas may briefly dip to near freezing around sunrise. 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. $$
3 follow-up statements
158 WWUS76 KEKA 290338 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 838 PM PDT Tue Sep 28 2021 CAZ106-108-110-111-291145- /O.CON.KEKA.FR.Y.0043.210929T0700Z-210929T1600Z/ Southern Humboldt Interior-Southern Trinity- Northwestern Mendocino Interior-Northeastern Mendocino Interior- 838 PM PDT Tue Sep 28 2021 ...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM PDT WEDNESDAY... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Trinity, Northwestern Mendocino Interior, Northeastern Mendocino Interior and Southern Humboldt Interior Counties. * WHEN...From midnight tonight to 9 AM PDT Wednesday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
540 WWUS76 KEKA 291011 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 311 AM PDT Wed Sep 29 2021 CAZ106-291115- /O.CAN.KEKA.FR.Y.0043.000000T0000Z-210929T1600Z/ Southern Humboldt Interior- 311 AM PDT Wed Sep 29 2021 ...FROST ADVISORY IS CANCELLED... Clouds have moved in and temperature are not as cold as expected. $$ CAZ108-110-111-291600- /O.CON.KEKA.FR.Y.0043.000000T0000Z-210929T1600Z/ Southern Trinity-Northwestern Mendocino Interior- Northeastern Mendocino Interior- 311 AM PDT Wed Sep 29 2021 ...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT THIS MORNING... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...Southern Trinity, Northwestern Mendocino Interior and Northeastern Mendocino Interior Counties. * WHEN...Until 9 AM PDT this morning. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. Frost Advisories and Freeze Warnings are issued during the local growing season as defined by climatology and local agriculture experts. Once the growing season has ended these statements will no longer be issued until the spring. && $$
635 WWUS76 KEKA 291548 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 848 AM PDT Wed Sep 29 2021 CAZ108-110-111-291700- /O.EXP.KEKA.FR.Y.0043.000000T0000Z-210929T1600Z/ Southern Trinity-Northwestern Mendocino Interior- Northeastern Mendocino Interior- 848 AM PDT Wed Sep 29 2021 ...FROST ADVISORY WILL EXPIRE AT 9 AM PDT THIS MORNING... $$
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.