Alert archive / California / Frost Advisories in 2012

Frost Advisory 2, NWS San Francisco Bay Area, CA

April 5, 20124 counties in California

NWS San Francisco Bay Area, CA issued this frost advisory at Apr 5, 2012, 8:17 PM PDT for 4 counties in California. It took effect at Apr 6, 2012, 3:00 AM PDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Apr 5, 2012, 8:17 PM PDT (03:17 UTC)
In effect from
Apr 6, 2012, 3:00 AM PDT
Expired
Apr 6, 2012, 8:00 AM PDT
In force
5 hr
Issued by
NWS San Francisco Bay Area, CA

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

The radar

The San Francisco radar (KMUX), 84 km from the middle of the area, began a volume at 03:17 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 00:00Z, 3.3 hours before the alert went out and 16 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, Oakland, CA at 00:00Z on 2012-04-06Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 00:00Z on 2012-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 square meters per square second.1939587897117Sfc1 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
1593 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
-13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

896 
WWUS76 KMTR 060317
NPWMTR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
817 PM PDT THU APR 5 2012

CAZ506-507-061130-
/O.NEW.KMTR.FR.Y.0002.120406T1000Z-120406T1500Z/
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
817 PM PDT THU APR 5 2012

...FROST ADVISORY IN EFFECT FROM 3 AM TO 8 AM PDT FRIDAY...

THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
ISSUED A FROST ADVISORY...WHICH IS IN EFFECT FROM 3 AM TO 8 AM
PDT FRIDAY. 

* TEMPERATURE: LOWS IN THE UPPER 20S TO MIDDLE 30S CAN BE 
  EXPECTED WITH THE COOLEST READINGS IN SHELTERED LOCATIONS. 

* LOCATION: THE NORTH BAY VALLEYS PLUS NORTH BAY MOUNTAINS UNDER
  1000 FEET. 

* IMPACTS: COLD TEMPERATURES COULD LEAD TO PLANTS BEING KILLED IF
  LEFT UNCOVERED. IN ADDITION...PATCHY FROST COULD MAKE FOR SLICK
  ROADWAYS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED. 

&&

$$

CAZ516-061130-
/O.NEW.KMTR.FR.Y.0002.120406T1000Z-120406T1500Z/
SOUTHERN SALINAS VALLEY...ARROYO SECO...AND LAKE SAN ANTONIO-
817 PM PDT THU APR 5 2012

...FROST ADVISORY IN EFFECT FROM 3 AM TO 8 AM PDT FRIDAY...

THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
ISSUED A FROST ADVISORY...WHICH IS IN EFFECT FROM 3 AM TO 8 AM
PDT FRIDAY. 

* TEMPERATURE: LOWS IN THE UPPER 20S TO MIDDLE 30S CAN BE 
  EXPECTED WITH THE COOLEST READINGS IN SHELTERED LOCATIONS. 

* LOCATION: THE SOUTHERN SALINAS VALLEY.

* IMPACTS: COLD TEMPERATURES COULD LEAD TO PLANTS BEING KILLED IF
  LEFT UNCOVERED. IN ADDITION...PATCHY FROST COULD MAKE FOR SLICK
  ROADWAYS.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED. 

&&

$$
2 follow-up statements
378 
WWUS76 KMTR 061023
NPWMTR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
323 AM PDT FRI APR 6 2012

CAZ506-507-061500-
/O.CON.KMTR.FR.Y.0002.000000T0000Z-120406T1500Z/
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
323 AM PDT FRI APR 6 2012

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

THE FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING.

* TEMPERATURE: LOWS IN THE UPPER 20S TO MIDDLE 30S THROUGH 8 AM
  WITH THE COLDEST READINGS IN WIND SHELTERED LOCATIONS.

* LOCATION: ALL NORTH BAY VALLEY FLOORS INCLUDING THE NORTH BAY
  MOUNTAINS WITH VALLEY LOCATIONS UNDER 1000 FEET.

* IMPACTS: COLD TEMPERATURES COULD LEAD TO PLANTS BEING KILLED 
  IF LEFT UNCOVERED. IN ADDITION...PATCHY FROST COULD MAKE FOR 
  SLICK ROADWAYS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$

CAZ516-061500-
/O.CON.KMTR.FR.Y.0002.000000T0000Z-120406T1500Z/
SOUTHERN SALINAS VALLEY...ARROYO SECO...AND LAKE SAN ANTONIO-
323 AM PDT FRI APR 6 2012

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

THE FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING.

* TEMPERATURE: LOWS IN THE UPPER 20S TO MIDDLE 30S THIS MORNING
  WITH THE COLDEST READINGS IN WIND SHELTERED LOCATIONS.

* LOCATION: THE SOUTHERN SALINAS VALLEY.

* IMPACTS: COLD TEMPERATURES COULD LEAD TO PLANTS BEING KILLED 
  IF LEFT UNCOVERED. IN ADDITION...PATCHY FROST COULD MAKE FOR 
  SLICK ROADWAYS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
376 
WWUS76 KMTR 061500
NPWMTR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
800 AM PDT FRI APR 6 2012

...FROST ADVISORY HAS BEEN CANCELLED...


CAZ506-507-516-061600-
/O.CAN.KMTR.FR.Y.0002.000000T0000Z-120406T1500Z/
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
SOUTHERN SALINAS VALLEY...ARROYO SECO...AND LAKE SAN ANTONIO-
800 AM PDT FRI APR 6 2012

...FROST ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
CANCELLED THE FROST ADVISORY. 

TEMPERATURES ARE BEGINING TO WARM ENOUGH TO NO LONGER WARRANT A
FROST ADVISORY. 

$$

Nearby

Frost Advisories in California, 2012Every frost advisory in 2012

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.