Alert archive / California / Wind Advisories in 2021

Wind Advisory 49, NWS Los Angeles, CA

April 17, 2021Los Angeles County, California

NWS Los Angeles, CA issued this wind advisory at Apr 17, 2021, 7:26 PM PDT for Los Angeles County, California. It took effect at Apr 18, 2021, 5:00 AM PDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Apr 17, 2021, 7:26 PM PDT (02:26 UTC)
In effect from
Apr 18, 2021, 5:00 AM PDT
Expired
Apr 18, 2021, 2:00 PM PDT
In force
9 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 02:27 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 00:00Z, 2.4 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 00:00Z on 2021-04-18Temperature 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, San Diego, CA at 00:00Z on 2021-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.1939587897Sfc1 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
1622 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
-91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

346 
WWUS76 KLOX 180226
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
726 PM PDT Sat Apr 17 2021

CAZ046-054-181200-
/O.NEW.KLOX.WI.Y.0049.210418T1200Z-210418T2100Z/
Santa Monica Mountains Recreational Area-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Acton, Mount Wilson, and Sandberg
726 PM PDT Sat Apr 17 2021

...WIND ADVISORY IN EFFECT FROM 5 AM TO 2 PM PDT SUNDAY...

* WHAT...Northeast winds 15 to 30 mph with gusts up to 45 mph 
  expected.

* WHERE...Santa Monica Mountains and Los Angeles County 
  Mountains excluding the Santa Monica Range.

* WHEN...From 5 AM to 2 PM PDT Sunday.

* IMPACTS...Gusty winds will blow around unsecured objects and
  make driving difficult, especially for high profile vehicles.
  Tree limbs could be blown down and a few power outages may
  result. Major roadways that could be impacted by the gusty winds
  include Interstate 5 as well as Highways 14 and 39. The gusty
  Santa Ana winds combined with very warm temperatures and very
  low humidities will bring elevated fire weather conditions. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

CAZ044-045-088-547-181200-
/O.NEW.KLOX.WI.Y.0049.210418T1200Z-210418T2100Z/
Ventura County Interior Valleys-Ventura County Coastal Valleys-
Santa Clarita Valley-Los Angeles County San Fernando Valley-
Including the cities of Santa Paula, Fillmore, Ojai, Piru, 
Thousand Oaks, Simi Valley, Moorpark, Newbury Park, 
Santa Clarita, Newhall, Valencia, Woodland Hills, Northridge, 
Burbank, and Universal City
726 PM PDT Sat Apr 17 2021

...WIND ADVISORY IN EFFECT FROM 5 AM TO 2 PM PDT SUNDAY...

* WHAT...Northeast winds 15 to 25 mph with gusts 35 to 40 mph
  expected. Isolated gusts up to 45 mph likely in the windiest
  foothill locations. 

* WHERE...Ventura County Interior Valleys, Ventura County 
  Coastal Valleys, Santa Clarita Valley and San Fernando Valley.

* WHEN...From 5 AM to 2 PM PDT Sunday.

* IMPACTS...Gusty winds will blow around unsecured objects and
  make driving difficult, especially for high profile vehicles.
  Tree limbs could be blown down and a few power outages may
  result. Major roadways that could be impacted by the gusty winds
  include Interstates 5 and 405, as well as Highways 14,23, and
  118. The gusty Santa Ana winds combined with very warm
  temperatures and very low humidities will bring elevated fire 
  weather conditions. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

Gomberg
2 follow-up statements
777 
WWUS76 KLOX 181201
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
501 AM PDT Sun Apr 18 2021

CAZ046-054-182100-
/O.CON.KLOX.WI.Y.0049.000000T0000Z-210418T2100Z/
Santa Monica Mountains Recreational Area-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Acton, Mount Wilson, and Sandberg
501 AM PDT Sun Apr 18 2021

...WIND ADVISORY REMAINS IN EFFECT UNTIL 2 PM PDT THIS
AFTERNOON...

* WHAT...Northeast winds 15 to 30 mph with gusts up to 45 mph 
  expected.

* WHERE...Santa Monica Mountains and Los Angeles County 
  Mountains excluding the Santa Monica Range.

* WHEN...Until 2 PM PDT this afternoon.

* IMPACTS...Gusty winds will blow around unsecured objects and
  make driving difficult, especially for high profile vehicles.
  Tree limbs could be blown down and a few power outages may
  result. Major roadways that could be impacted by the gusty winds
  include Interstate 5 as well as Highways 14 and 39. The gusty
  Santa Ana winds combined with very warm temperatures and very
  low humidities will bring elevated fire weather conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

CAZ044-045-088-547-182100-
/O.CON.KLOX.WI.Y.0049.000000T0000Z-210418T2100Z/
Ventura County Interior Valleys-Ventura County Coastal Valleys-
Santa Clarita Valley-Los Angeles County San Fernando Valley-
Including the cities of Santa Paula, Fillmore, Ojai, Piru, 
Thousand Oaks, Simi Valley, Moorpark, Newbury Park, 
Santa Clarita, Newhall, Valencia, Woodland Hills, Northridge, 
Burbank, and Universal City
501 AM PDT Sun Apr 18 2021

...WIND ADVISORY REMAINS IN EFFECT UNTIL 2 PM PDT THIS
AFTERNOON...

* WHAT...Northeast winds 15 to 25 mph with gusts 35 to 40 mph 
  expected. Isolated gusts up to 45 mph likely in the windiest 
  foothill locations.

* WHERE...Ventura County Interior Valleys, Ventura County 
  Coastal Valleys, Santa Clarita Valley and San Fernando Valley.

* WHEN...Until 2 PM PDT this afternoon.

* IMPACTS...Gusty winds will blow around unsecured objects and
  make driving difficult, especially for high profile vehicles.
  Tree limbs could be blown down and a few power outages may
  result. Major roadways that could be impacted by the gusty winds
  include Interstates 5 and 405, as well as Highways 14,23, and
  118. The gusty Santa Ana winds combined with very warm
  temperatures and very low humidities will bring elevated fire
  weather conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

Rorke
567 
WWUS76 KLOX 182116
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
216 PM PDT Sun Apr 18 2021

CAZ044>046-054-088-547-182230-
/O.EXP.KLOX.WI.Y.0049.000000T0000Z-210418T2100Z/
Ventura County Interior Valleys-Ventura County Coastal Valleys-
Santa Monica Mountains Recreational Area-
Los Angeles County Mountains excluding the Santa Monica Range-
Santa Clarita Valley-Los Angeles County San Fernando Valley-
Including the cities of Santa Paula, Fillmore, Ojai, Piru, 
Thousand Oaks, Simi Valley, Moorpark, Newbury Park, Acton, 
Mount Wilson, Sandberg, Santa Clarita, Newhall, Valencia, 
Woodland Hills, Northridge, Burbank, and Universal City
216 PM PDT Sun Apr 18 2021

...WIND ADVISORY HAS EXPIRED...

Winds have diminished across the area and the Wind Advisory was
allowed to expire at 2 PM PDT. However, breezy to windy conditions
with local gusts up to 40 to 50 mph will prevail thru mid
afternoon.

$$

Sirard

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 18, 2:25 AM PDTSmall Craft AdvisoryLOX25 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.