Alert archive / California / Red Flag Warnings in 2021

Red Flag Warning 4, NWS Los Angeles, CA

July 17, 2021Santa Barbara County, California

NWS Los Angeles, CA issued this red flag warning at Jul 17, 2021, 2:56 PM PDT for Santa Barbara County, California. It took effect at Jul 18, 2021, 6:00 AM PDT. It was in force for 22 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 17, 2021, 2:56 PM PDT (21:56 UTC)
In effect from
Jul 18, 2021, 6:00 AM PDT
Expired
Jul 19, 2021, 3:43 AM PDT
In force
22 hr
Issued by
NWS Los Angeles, CA

County Santa Barbara County, CA

The radar

The Vandenberg AFB radar (KVBX), 47 km from the middle of the area, began a volume at 21:56 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 9.9 hours before the alert went out and 48 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, Vandenberg AFB, CA at 12:00Z on 2021-07-17Temperature 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, Vandenberg AFB, CA at 12:00Z on 2021-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
2243 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

314 
WWUS86 KLOX 172156 CCA
RFWLOX

URGENT - FIRE WEATHER MESSAGE...CORRECTED
National Weather Service Los Angeles/Oxnard CA
256 PM PDT Sat Jul 17 2021

...RED FLAG WARNING IN EFFECT FROM SUNDAY MORNING THROUGH MONDAY 
MORNING FOR SANTA BARBARA AND SAN LUIS OBISPO COUNTIES AND VENTURA
COUNTY MOUNTAINS DUE TO INCREASED THREAT OF THUNDERSTORMS WITH 
POTENTIAL FOR DRY LIGHTNING AND GUSTY ERRATIC WINDS...

.Monsoonal moisture with increased instability will overspread Southwest
California later tonight into Monday. An upper level disturbance will
bring a threat of thunderstorms to Los Angeles and Ventura counties
starting late tonight, shifting northwestward into Santa Barbara and
San Luis Obispo counties on Sunday. A moist monsoonal pattern will
continue to bring a slight chance of showers and thunderstorms to
much of Southwest California through at least Monday morning. With
higher moisture content across the southern portions of our 
forecast area, most of the storms over Los Angeles County and the 
coastal/valley areas of Ventura county are expected to be wetter, 
however, there is still a threat of isolated dry lightning strikes
across the periphery of storms. As storms transition northwestward
into Santa Barbara and San Luis Obispo Counties as well as the 
Ventura County mountains, there is a greater threat of drier storms
mixing with wet storms, along with gusty outflow winds, resulting
in an increased risk of fire ignitions and rapid fire spread in 
these areas. Given the very dry fuels, any lightning strikes will 
be problematic, especially across Santa Barbara and San Luis 
Obispo counties, as well as the Ventura county mountains.


CAZ234>239-251-252-181730-
/O.UPG.KLOX.FW.A.0004.210718T1300Z-210719T1700Z/
/O.NEW.KLOX.FW.W.0004.210718T1300Z-210719T1700Z/
San Luis Obispo County Central Coast-
Santa Barbara County Central Coast-Santa Ynez Valley-
San Luis Obispo County Interior Valleys-Cuyama Valley-
Santa Barbara County South Coast-
San Luis Obispo County Mountains / Los Padres National Forest-
Santa Barbara County Mountains-
256 PM PDT Sat Jul 17 2021

...RED FLAG WARNING IN EFFECT FROM 6 AM SUNDAY TO 10 AM PDT MONDAY
FOR SANTA BARBARA AND SAN LUIS OBISPO COUNTIES DUE TO INCREASED 
THREAT OF THUNDERSTORMS WITH POTENTIAL FOR DRY LIGHTNING AND GUSTY
OUTFLOW WINDS...

The National Weather Service in Los Angeles/Oxnard has issued a
Red Flag Warning FOR THUNDERSTORMS WITH POTENTIAL FOR DRY
LIGHTNING AND GUSTY OUTFLOW WINDS, which is in effect from 6 AM 
Sunday to 10 AM PDT Monday. The Fire Weather Watch is no longer in
effect.

* Impacts...Given the very dry fuels, any cloud to ground
  lightning strikes have the potential of starting new wildfires
  across the warning area. Gusty and erratic winds with
  thunderstorms will also bring the threat of rapid fire spread
  with any new ignitions. For coastal areas, the greatest threat
  of fire ignitions and spread will be coastal foothills and 
  interior areas where fuels are driest. 

* Thunderstorms...Increased threat of isolated to scattered dry
  and wet thunderstorms that could produce little rainfall, 
  accompanied with cloud to ground lightning.

* Outflow Winds...Strong and erratic wind gusts up to 40 mph are 
  possible near any thunderstorms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are expected shortly. A combination of extremely dry fuels, gusty
erratic winds and lightning associated with thunderstorms can 
result in extreme fire behavior.


&&

$$

CAZ253-181730-
/O.NEW.KLOX.FW.W.0004.210718T1300Z-210719T1700Z/
Ventura County Mountains / Los Padres National Forest-
256 PM PDT Sat Jul 17 2021

...RED FLAG WARNING IN EFFECT FROM 6 AM SUNDAY TO 10 AM PDT
MONDAY FOR THE VENTURA COUNTY MOUNTAINS DUE TO INCREASED 
THREAT OF THUNDERSTORMS WITH POTENTIAL FOR DRY LIGHTNING AND GUSTY
OUTFLOW WINDS...

The National Weather Service in Los Angeles/Oxnard has issued a
Red Flag Warning FOR THUNDERSTORMS WITH POTENTIAL FOR DRY
LIGHTNING AND GUSTY OUTFLOW WINDS, which is in effect from 6 AM 
Sunday to 10 AM PDT Monday. 

* Impacts...Given the very dry fuels, any cloud to ground
  lightning strikes have the potential of starting new wildfires
  across the warning area. Gusty and erratic winds with
  thunderstorms will also bring the threat of rapid fire spread
  with any new ignitions.

* Thunderstorms...Increased threat of isolated to scattered dry
  and wet thunderstorms that could produce little rainfall, 
  accompanied with cloud to ground lightning.

* Outflow Winds...Strong and erratic wind gusts up to 40 mph are 
  possible near any thunderstorms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are expected shortly. A combination of extremely dry fuels, gusty
erratic winds and lightning associated with thunderstorms can 
result in extreme fire behavior.

&&

$$

Gomberg
3 follow-up statements
825 
WWUS86 KLOX 181642
RFWLOX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
942 AM PDT Sun Jul 18 2021

...RED FLAG WARNING IN EFFECT THROUGH 10 AM MONDAY MORNING FOR 
SANTA BARBARA AND SAN LUIS OBISPO COUNTIES AND VENTURA COUNTY 
MOUNTAINS DUE TO INCREASED THREAT OF THUNDERSTORMS WITH POTENTIAL 
FOR DRY LIGHTNING AND GUSTY ERRATIC WINDS...

.Monsoonal moisture and associated instability will continue to increase across
Southwest California through the day into tonight, increasing across
San Luis Obispo and Santa Barbara counties this afternoon and evening.
As the monsoonal moisture interacts with an upper level disturbance
off the coast, there is still the concern of increased lightning 
activity this afternoon into Monday morning. As storms transition 
northwestward into Santa Barbara and San Luis Obispo counties, as
well as the Ventura county mountains, there is a greater threat 
of drier storms mixing with wet storms along with gusty outflow 
winds, resulting in an increased risk of fire ignitions and rapid 
fire spread across these areas. Given the very dry fuels, any 
lightning strikes will be problematic, especially across Santa 
Barbara and San Luis Obispo counties, as well as the Ventura 
county mountains. While there is increased moisture across coastal
and valley areas of Los Angeles and Ventura counties, there is 
some concern that the mountains of Los Angeles county and Antelope
Valley could see somewhat drier storms than previously 
anticipated, so if any additional organized convection becomes 
imminent for these areas, the Red Flag Warning may be expanded for
these locations. 

CAZ234>239-251>253-182300-
/O.CON.KLOX.FW.W.0004.000000T0000Z-210719T1700Z/
San Luis Obispo County Central Coast-
Santa Barbara County Central Coast-Santa Ynez Valley-
San Luis Obispo County Interior Valleys-Cuyama Valley-
Santa Barbara County South Coast-
San Luis Obispo County Mountains / Los Padres National Forest-
Santa Barbara County Mountains-
Ventura County Mountains / Los Padres National Forest-
942 AM PDT Sun Jul 18 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 AM PDT MONDAY FOR
SANTA BARBARA AND SAN LUIS OBISPO COUNTIES AS WELL AS THE VENTURA
COUNTY MOUNTAINS DUE TO INCREASED THREAT OF THUNDERSTORMS WITH 
POTENTIAL FOR DRY LIGHTNING AND GUSTY OUTFLOW WINDS...

* Impacts...Given the very dry fuels, any cloud to ground 
  lightning strikes have the potential of starting new wildfires 
  across the warning area. Gusty and erratic winds with 
  thunderstorms will also bring the threat of rapid fire spread 
  with any new ignitions. For coastal areas, the greatest threat 
  of fire ignitions and spread will be coastal foothills and 
  interior areas where fuels are driest.

* Thunderstorms...Increased threat of isolated to scattered dry 
  and wet thunderstorms that could produce little rainfall, 
  accompanied with cloud to ground lightning.

* Outflow Winds...Strong and erratic wind gusts up to 40 mph are 
  possible near any thunderstorms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are expected shortly. A combination of extremely dry fuels, gusty
erratic winds and lightning associated with thunderstorms can
result in extreme fire behavior.

&&

$$
744 
WWUS86 KLOX 182150
RFWLOX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
250 PM PDT Sun Jul 18 2021

...RED FLAG WARNING IN EFFECT THROUGH 10 AM MONDAY MORNING FOR
SANTA BARBARA AND SAN LUIS OBISPO COUNTIES AND VENTURA COUNTY
MOUNTAINS DUE TO INCREASED THREAT OF THUNDERSTORMS WITH POTENTIAL
FOR DRY LIGHTNING AND GUSTY ERRATIC WINDS...

.Monsoonal moisture and associated instability will continue to bring a threat
of showers and thunderstorms to portions of Southwest California through
Monday morning, with a slight chance of storms lingering across the Los
Angeles and Ventura county mountains and Antelope Valley on Monday afternoon.
As the monsoonal moisture interacts with an upper level disturbance off the coast, 
there is still the concern of lightning activity this afternoon into Monday
morning. Any thunderstorms that develop across Santa Barbara and San Luis Obispo
counties, as well as the Ventura county mountains, will have a greater threat of
drier storms mixing with wet storms along with gusty outflow winds, resulting 
in an increased risk of fire ignitions and rapid fire spread. Given the very dry
fuels, any lightning strikes will be problematic. While there is increased moisture
across coastal and valley areas of Los Angeles and Ventura counties, there is some 
concern that the mountains of Los Angeles county and Antelope Valley could see
somewhat drier storms than previously anticipated. 


CAZ234>239-251>253-191700-
/O.CON.KLOX.FW.W.0004.000000T0000Z-210719T1700Z/
San Luis Obispo County Central Coast-
Santa Barbara County Central Coast-Santa Ynez Valley-
San Luis Obispo County Interior Valleys-Cuyama Valley-
Santa Barbara County South Coast-
San Luis Obispo County Mountains / Los Padres National Forest-
Santa Barbara County Mountains-
Ventura County Mountains / Los Padres National Forest-
250 PM PDT Sun Jul 18 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 AM PDT MONDAY FOR
SANTA BARBARA AND SAN LUIS OBISPO COUNTIES AS WELL AS THE VENTURA
COUNTY MOUNTAINS DUE TO THREAT OF THUNDERSTORMS WITH POTENTIAL 
FOR DRY LIGHTNING AND GUSTY OUTFLOW WINDS...

* Impacts...Given the very dry fuels, any cloud to ground 
  lightning strikes have the potential of starting new wildfires 
  across the warning area. Gusty and erratic winds with 
  thunderstorms will also bring the threat of rapid fire spread 
  with any new ignitions. For coastal areas, the greatest threat 
  of fire ignitions and spread will be coastal foothills and 
  interior areas where fuels are driest.

* Thunderstorms...Threat of isolated to widely scattered dry and 
  wet thunderstorms that could produce little rainfall, 
  accompanied with cloud to ground lightning.

* Outflow Winds...Strong and erratic wind gusts up to 40 mph are 
  possible near any thunderstorms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are expected shortly. A combination of extremely dry fuels, gusty
erratic winds and lightning associated with thunderstorms can
result in extreme fire behavior.

&&

$$

Gomberg
713 
WWUS86 KLOX 191043
RFWLOX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
343 AM PDT Mon Jul 19 2021

CAZ234>239-251>253-191145-
/O.CAN.KLOX.FW.W.0004.000000T0000Z-210719T1700Z/
San Luis Obispo County Central Coast-
Santa Barbara County Central Coast-Santa Ynez Valley-
San Luis Obispo County Interior Valleys-Cuyama Valley-
Santa Barbara County South Coast-
San Luis Obispo County Mountains / Los Padres National Forest-
Santa Barbara County Mountains-
Ventura County Mountains / Los Padres National Forest-
343 AM PDT Mon Jul 19 2021

...RED FLAG WARNING IS CANCELLED FOR SANTA BARBARA AND SAN LUIS
OBISPO COUNTIES AS WELL AS THE VENTURA COUNTY MOUNTAINS...

The National Weather Service in Los Angeles/Oxnard has cancelled
the Red Flag Warning.

The the chance or thunderstorms has diminished to under 10 percent
this morning. Since the chance of thunderstorms is now so low the
Red Flag Warning for dry lightning has been cancelled.

There is a slight chance of a thunderstorm over the eastern San 
Gabriel mountains this afternoon during peak heating.

$$

Rorke

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 9:54 AM PDTFire Weather WatchLOXSanta Barbara5 hr

Nearby

Red Flag Warnings in California, 2021Every red flag warning 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.