Alert archive / California / Wind Advisories in 2021

Wind Advisory 11, NWS San Francisco Bay Area, CA

October 19, 20219 counties in California

NWS San Francisco Bay Area, CA issued this wind advisory at Oct 19, 2021, 1:39 PM PDT for 9 counties in California. It took effect at Oct 19, 2021, 8:00 PM PDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Oct 19, 2021, 1:39 PM PDT (20:39 UTC)
In effect from
Oct 19, 2021, 8:00 PM PDT
Expired
Oct 20, 2021, 3:16 AM PDT
In force
7 hr
Issued by
NWS San Francisco Bay Area, CA

Counties Alameda County, CA, City and County of San Francisco, CA, Contra Costa County, CA, Marin County, CA, Napa County, CA, San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA, Sonoma County, CA

The radar

The San Francisco radar (KMUX), 78 km from the middle of the area, began a volume at 20:39 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 12:00Z, 8.7 hours before the alert went out and 9 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 12:00Z on 2021-10-19Temperature 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 12:00Z on 2021-10-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
856 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

131 
WWUS76 KMTR 192039
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
139 PM PDT Tue Oct 19 2021

...Gusty Southerly Winds Overnight...

CAZ006-505-506-508-509-201100-
/O.NEW.KMTR.WI.Y.0011.211020T0300Z-211020T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Bay Shoreline-
San Francisco Peninsula Coast-
Including the cities of San Francisco, Tamalpais-Homestead, 
Sausalito, Santa Rosa, South Santa Rosa, Napa, San Rafael, 
Petaluma, Novato, Rohnert Park, Oakland, Fremont, Hayward, 
Daly City, Berkeley, and Pacifica
139 PM PDT Tue Oct 19 2021

...WIND ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO 4 AM PDT
WEDNESDAY...

* WHAT...South winds 15 to 25 mph with gusts 30 to 45 mph
  expected, locally up to or exceeding 50 mph in the windiest
  locations.

* WHERE...San Francisco, Coastal North Bay Including Point Reyes 
  National Seashore, North Bay Interior Valleys, San Francisco 
  Bay Shoreline and San Francisco Peninsula Coast.

* WHEN...From 8 PM this evening to 4 AM PDT Wednesday. The
  strongest winds are expected around to just after midnight.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

* ADDITIONAL DETAILS...A 35 to 50 mph low level jet located a few
  hundred to a couple thousand feet above the surface has the
  potential to occasionally mix down and result in gusty southerly
  winds overnight. The strongest winds will be along the coast of
  the North Bay and San Francisco Peninsula but will also filter
  into portions of the San Francisco Bayshore, North Bay Valleys,
  and across the hills throughout the region.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr
1 follow-up statement
029 
WWUS76 KMTR 201016
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
316 AM PDT Wed Oct 20 2021

CAZ006-505-506-508-509-201130-
/O.CAN.KMTR.WI.Y.0011.000000T0000Z-211020T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Bay Shoreline-
San Francisco Peninsula Coast-
Including the cities of San Francisco, Tamalpais-Homestead, 
Sausalito, Santa Rosa, South Santa Rosa, Napa, San Rafael, 
Petaluma, Novato, Rohnert Park, Oakland, Fremont, Hayward, 
Daly City, Berkeley, and Pacifica
316 AM PDT Wed Oct 20 2021

...WIND ADVISORY IS CANCELLED...

While breezy to locally gusty winds to around 30 mph will be
possible this morning, wind speeds are no longer anticipated to
reach advisory criteria.

$$

For more information from the National Weather Service visit
http://weather.gov/mtr

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 19, 2:05 AM PDTGale WarningMTR25 hr
Oct 19, 2:05 AM PDTSmall Craft AdvisoryMTR5 days
Oct 19, 2:05 AM PDTSmall Craft AdvisoryMTR12 hr

Nearby

Wind Advisories in California, 2021Every wind 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.