Alert archive / California / Frost Advisories in 2012

Frost Advisory 3, NWS San Francisco Bay Area, CA

November 9, 20124 counties in California

NWS San Francisco Bay Area, CA issued this frost advisory at Nov 9, 2012, 6:42 PM PST for 4 counties in California. It took effect at Nov 10, 2012, 2:00 AM PST. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Nov 9, 2012, 6:42 PM PST (02:42 UTC)
In effect from
Nov 10, 2012, 2:00 AM PST
Expired
Nov 10, 2012, 8:00 AM PST
In force
6 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 02:45 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, 2.7 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 2012-11-10Temperature 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 2012-11-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1397 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
35 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.

971 
WWUS76 KMTR 100242
NPWMTR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
642 PM PST FRI NOV 9 2012

...AREAS OF FROST LIKELY LATE TONIGHT AND EARLY SATURDAY MORNING
IN THE COOLEST INTERIOR VALLEYS OF THE NORTH BAY AS WELL AS
SOUTHERN MONTEREY COUNTY...

.A COOL AIRMASS HAD SETTLED ACROSS NORTHERN AND CENTRAL CALIFORNIA
ON FRIDAY. SKIES WILL BE MOSTLY CLEAR OVERNIGHT FOR INLAND AREAS
WHICH WILL ALLOW TEMPERATURES TO FALL INTO THE LOWER TO MID 30S IN
THE COOLEST INLAND VALLEYS. AREAS OF FROST ARE EXPECTED LATE
FRIDAY NIGHT INTO EARLY SATURDAY MORNING. SATURDAY NIGHT IS ALSO
EXPECTED TO BE COOL WITH FROST ONCE AGAIN POSSIBLE THEN.

CAZ506-507-101600-
/O.NEW.KMTR.FR.Y.0003.121110T1000Z-121110T1600Z/
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
642 PM PST FRI NOV 9 2012

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM PST SATURDAY...

THE NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA HAS ISSUED A
FROST ADVISORY...WHICH IS IN EFFECT FROM 2 AM TO 8 AM PST
SATURDAY FOR INTERIOR SECTIONS OF THE NORTH BAY.

* TEMPERATURE: OVERNIGHT LOWS ARE EXPECTED TO BE IN THE LOWER TO
  MID 30S. THE COLDEST LOCATIONS MAY SEE TEMPERATURES BRIEFLY DROP
  TO AROUND FREEZING.

* TIMING: THE COLDEST TEMPERATURES WILL OCCUR FOR A FEW HOURS
  AROUND SUNRISE ON SATURDAY MORNING.

* IMPACTS: SENSITIVE VEGETATION MAY BE DAMAGED BY FROST.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

CAZ516-101600-
/O.NEW.KMTR.FR.Y.0003.121110T1000Z-121110T1600Z/
SOUTHERN SALINAS VALLEY...ARROYO SECO...AND LAKE SAN ANTONIO-
642 PM PST FRI NOV 9 2012

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM PST SATURDAY...

THE NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA HAS ISSUED A
FROST ADVISORY...WHICH IS IN EFFECT FROM 2 AM TO 8 AM PST
SATURDAY FOR THE SOUTHERN SALINAS VALLEY AND OTHER INTERIOR
VALLEYS OF SOUTHERN MONTEREY COUNTY.

* TEMPERATURE: OVERNIGHT LOWS ARE EXPECTED TO BE IN THE LOWER TO
  MID 30S. THE COLDEST LOCATIONS MAY SEE TEMPERATURES BRIEFLY DROP
  TO AROUND FREEZING.

* TIMING: THE COLDEST TEMPERATURES WILL OCCUR FOR A FEW HOURS
  AROUND SUNRISE ON SATURDAY MORNING.

* IMPACTS: SENSITIVE VEGETATION MAY BE DAMAGED BY FROST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

DYKEMA
1 follow-up statement
304 
WWUS76 KMTR 101551
NPWMTR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
751 AM PST SAT NOV 10 2012


CAZ506-507-101700-
/O.EXP.KMTR.FR.Y.0003.000000T0000Z-121110T1600Z/
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
751 AM PST SAT NOV 10 2012

...FROST ADVISORY WILL EXPIRE AT 8 AM PST THIS MORNING...

THE FROST ADVISORY WILL EXPIRE AT 8 AM PST THIS MORNING. 

TEMPERATURES WILL CONTINUE TO RISE THROUGH THE MORNING HOURS.
THEREFORE...THE FROST ADVISORY WILL BE ALLOW TO EXPIRE.

$$

CAZ516-101700-
/O.EXP.KMTR.FR.Y.0003.000000T0000Z-121110T1600Z/
SOUTHERN SALINAS VALLEY...ARROYO SECO...AND LAKE SAN ANTONIO-
751 AM PST SAT NOV 10 2012

...FROST ADVISORY WILL EXPIRE AT 8 AM PST THIS MORNING...

THE FROST ADVISORY WILL EXPIRE AT 8 AM PST THIS MORNING. 

TEMPERATURES WILL CONTINUE TO RISE THROUGH THE MORNING HOURS.
THEREFORE...THE FROST ADVISORY WILL BE ALLOW TO EXPIRE.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 10, 10:13 AM PSTFrost AdvisoryMTRMarin, Monterey, Napa, Sonoma22 hr

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.