Alert archive / California / Frost Advisories in 2024

Frost Advisory 8, NWS San Francisco Bay Area, CA

February 7, 20245 counties in California

NWS San Francisco Bay Area, CA issued this frost advisory at Feb 7, 2024, 3:10 AM PST for 5 counties in California. It took effect at Feb 7, 2024, 10:00 PM PST. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Feb 7, 2024, 3:10 AM PST (11:10 UTC)
In effect from
Feb 7, 2024, 10:00 PM PST
Expired
Feb 8, 2024, 9:00 AM PST
In force
11 hr
Issued by
NWS San Francisco Bay Area, CA

Counties Marin County, CA, Monterey County, CA, Napa County, CA, San Benito County, CA, Sonoma County, CA

The radar

The San Francisco radar (KMUX), 50 km from the middle of the area, began a volume at 11:12 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

Vandenberg AFB, CA (KVBG), launched 00:00Z, 11.2 hours before the alert went out and 348 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.

Skew-T log-pSkew-T log-p diagram, Vandenberg AFB, CA at 00:00Z on 2024-02-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Vandenberg AFB, CA at 00:00Z on 2024-02-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
20 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
893 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
-31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 7, 11:29 AM PSTSpecial Marine WarningMTR31 min
Feb 7, 11:59 AM PSTSpecial Weather StatementMTRSanta Cruz31 min
Feb 7, 12:10 PM PSTSpecial Marine WarningMTR35 min
Feb 7, 12:41 PM PSTSpecial Marine WarningMTR34 min
Feb 7, 12:48 PM PSTSpecial Weather StatementMTRSanta Cruz27 min
Feb 7, 1:09 PM PSTSpecial Marine WarningMTR36 min

Nearby

Frost Advisories in California, 2024Every frost advisory in 2024

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.