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Red Flag Warning


URGENT - FIRE WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
309 PM PST Sun Dec 10 2017

...RED FLAG WARNING IN EFFECT FOR MUCH OF LOS ANGELES AND VENTURA
COUNTIES THROUGH MONDAY EVENING FOR GUSTY NORTHEAST WINDS AND LOW
RELATIVE HUMIDITY...

...RED FLAG WARNING IN EFFECT FOR THE SANTA BARBARA COUNTY
MOUNTAINS UNTIL 6PM THIS EVENING FOR PLUME DEVELOPMENT AND LOW
RELATIVE HUMIDITY...

.DISCUSSION...An extended period of Santa Ana offshore winds will
continue through Monday focused over much of Los Angeles and
Ventura Counties. East winds of 20 to 30 mph with gusts up to
45 mph will continue at times this afternoon then redevelop with
gusts 30-40 mph late tonight and Monday, however, winds are
expected to be weaker overall on Monday. Meanwhile, minimum
humidities of 3 to 10 percent will be common through at least the
middle of next week, with widespread poor overnight recoveries
mostly staying under 30 percent. As a result, critical Red Flag
conditions will persist over most of Los Angeles and Ventura
Counties through Monday with a chance for locally critical
conditions continuing into Tuesday especially in the valleys and
mountains. The Santa Barbara County Mountains will also remain in
critical fire weather conditions until sunset due to plume
development of the existing Thomas Fire and very low humidity.
There is a chance of additional plume growth on Monday.

CAZ246-253-254-111800-
/O.CON.KLOX.FW.W.0009.000000T0000Z-171212T0400Z/
Santa Monica Mountains Recreational Area-
Ventura County Mountains / Los Padres National Forest-
Los Angeles County Mountains / Angeles National Forest-
309 PM PST Sun Dec 10 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM PST MONDAY FOR
STRONG NORTHEAST WINDS AND LOW RELATIVE HUMIDITY OVER THE LOS
ANGELES AND VENTURA COUNTY MOUNTAINS...

* Winds...Northeast 15 to 25 mph with gusts up to 40 mph.

* Relative Humidity...3 to 10 percent with poor overnight
  recoveries.

* Impacts...If fire ignition occurs, there will be the potential
  for very rapid spread of wildfire with long range spotting and
  extreme fire behavior that could lead to a threat to life and
  property. Use extreme caution with potential fire ignition
  sources.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are expected. A combination of gusty winds and low relative
humidity can contribute to extreme fire behavior. Use extreme
caution when using potential fire ignition sources. This is a
dangerous situation, please follow evacuation orders.

&&

$$

URGENT - FIRE WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
309 PM PST Sun Dec 10 2017

...RED FLAG WARNING IN EFFECT FOR MUCH OF LOS ANGELES AND VENTURA
COUNTIES THROUGH MONDAY EVENING FOR GUSTY NORTHEAST WINDS AND LOW
RELATIVE HUMIDITY...

...RED FLAG WARNING IN EFFECT FOR THE SANTA BARBARA COUNTY
MOUNTAINS UNTIL 6PM THIS EVENING FOR PLUME DEVELOPMENT AND LOW
RELATIVE HUMIDITY...

.DISCUSSION...An extended period of Santa Ana offshore winds will
continue through Monday focused over much of Los Angeles and
Ventura Counties. East winds of 20 to 30 mph with gusts up to
45 mph will continue at times this afternoon then redevelop with
gusts 30-40 mph late tonight and Monday, however, winds are
expected to be weaker overall on Monday. Meanwhile, minimum
humidities of 3 to 10 percent will be common through at least the
middle of next week, with widespread poor overnight recoveries
mostly staying under 30 percent. As a result, critical Red Flag
conditions will persist over most of Los Angeles and Ventura
Counties through Monday with a chance for locally critical
conditions continuing into Tuesday especially in the valleys and
mountains. The Santa Barbara County Mountains will also remain in
critical fire weather conditions until sunset due to plume
development of the existing Thomas Fire and very low humidity.
There is a chance of additional plume growth on Monday.

CAZ252-110200-
/O.CON.KLOX.FW.W.0009.000000T0000Z-171211T0200Z/
Santa Barbara County Mountains-
309 PM PST Sun Dec 10 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS EVENING
FOR PLUME DEVELOPMENT AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS
OF SANTA BARBARA COUNTY...

* Plume Development...Deep vertical mixing will allow for large
  plume growth and rapid fire spread until sunset.

* Winds...East 5 to 15 mph with gusts up to 20 mph.

* Relative Humidity...3 to 10 percent with poor overnight
  recoveries.

* Impacts...If fire ignition occurs, there will be the potential
  for very rapid spread of wildfire with long range spotting and
  extreme fire behavior that could lead to a threat to life and
  property. Use extreme caution with potential fire ignition
  sources.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are expected. A combination of plume development, locally gusty
winds and low relative humidity can contribute to extreme fire
behavior. Use extreme caution when using potential fire ignition
sources. This is a dangerous situation, please follow evacuation
orders.

&&

$$


Air Quality Alert


CAZ034-037-051-111800-
San Luis Obispo County Central Coast-
San Luis Obispo County Interior Valleys-
San Luis Obispo County Mountains-
Including the cities of San Luis Obispo, Pismo Beach, Morro Bay,
Cambria, San Simeon, Paso Robles, Atascadero, and Black Mountain
304 PM PST Fri Dec 8 2017

...AIR QUALITY ALERT DUE TO SMOKE IMPACTS FROM WILDFIRES EXTENDED
THROUGH 10 AM PST MONDAY...

The San Luis Obispo County Air Pollution Control District has
extended an Air Quality Alert due to smoke impacts in San Luis
Obispo County through 10 am PST Monday. Smoke from the from wildfires
in Ventura and Los Angeles Counties is being transported into San
Luis Obispo County.

Exposure to particle pollution can cause serious health problems,
aggravate lung disease, cause asthma attacks and acute bronchitis,
and increase risk of respiratory infections.

Residents are advised to use caution as conditions warrant. People
with heart or lung disease should follow their doctors advice for
dealing with episodes of blowing dust.

Additionally, older adults and children should avoid prolonged
exposure, strenuous activity or heavy exertion, as conditions
dictate.

For the latest air quality forecasts and information, visit the San
Luis Obispo County Air Pollution Control District website at
www.slocleanair.org, or call 805.781.5912.

$$

15

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NOAA National Weather Service
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Silver Spring, MD 20910
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Page last modified: June 2, 2009
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