Alert archive / California / Frost Advisories in 2020

Frost Advisory 2, NWS Los Angeles, CA

February 4, 2020Los Angeles County, California

NWS Los Angeles, CA issued this frost advisory at Feb 4, 2020, 2:02 PM PST for Los Angeles County, California. It took effect at Feb 5, 2020, 1:00 AM PST. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Feb 4, 2020, 2:02 PM PST (22:02 UTC)
In effect from
Feb 5, 2020, 1:00 AM PST
Expired
Feb 5, 2020, 9:00 AM PST
In force
8 hr
Issued by
NWS Los Angeles, CA

County Los Angeles County, CA

The radar

The Santa Ana Mts radar (KSOX), 71 km from the middle of the area, began a volume at 22:05 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

San Diego, CA (KNKX), launched 12:00Z, 10.0 hours before the alert went out and 184 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, San Diego, CA at 12:00Z on 2020-02-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, San Diego, CA at 12:00Z on 2020-02-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3353 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this frost advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Los Angeles, CA wrote its last area forecast discussion before this frost advisory went out at Feb 4, 1:48 PM PST, 14 minutes earlier.

Area forecast discussion, Feb 4, 1:48 PM PST, 14 minutes before
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The office that day

Everything else NWS Los Angeles, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 3, 4:28 PM PSTBeach Hazards StatementLOXLos Angeles11 hr
Feb 4, 2:48 AM PSTHigh Wind WarningLOX6 hr
Feb 4, 3:06 AM PSTGale WarningLOX9 hr
Feb 4, 3:06 AM PSTSmall Craft AdvisoryLOX11 hr
Feb 4, 9:01 AM PSTFreeze WarningLOX24 hr
Feb 4, 9:01 AM PSTHard Freeze WarningLOXSanta Barbara25 hr
Feb 4, 2:12 PM PSTSmall Craft AdvisoryLOX13 hr

Nearby

Frost Advisories in California, 2020Every frost advisory in 2020

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.