Santa Ana Winds later this week in Southern CA

This time of year is Santa Anna Wind season in portions of southern California around Los Angeles. This means the possibility of elevated fire danger. So, fire season is still very much in the picture for these areas. As you will see from this article from the Press-Enterpirse, the air attack base at Hemet-Ryan is ready.

In October 2008, I posted a short article on santa ana winds where I linked to a webpage on Santa Ana Winds by Robert Fovell, professor of Atmospheric and Oceanic Sciences at the University of California. He also has a FAQ page on the santa ana winds.

I meant to write more about santa ana winds, but I don't think that I did. So, I'll be working on more articles about the santa ana winds over the next couple of weeks.

The NWS out of Los Angeles and Oxnard California (here is their website) has issued a special weather statement at 3:52 AM PDT on Monday, October 24 for moderate santa ana winds and very low relative humidities for late Wednesday Oct. 24 through Friday October 26. They have an excellent graphic of this wind advisory that may be found here, and I should warn you that this graphic seems to updated regularly. So, don't be surprised if you see a different graphic.

For Los Angeles and Ventura Counties, peak wind gusts in the mountains are expected to be 40 to 50 mph and slightly lower in the valleys (35 to 45 mph).

I'll be keeping on eye on this and if anything of note develops firewise during this expected santa ana wind event, I'll let you know.

Update on Oct. 25, 3:10 PM EDT. I just checked out the NWS - Los Angeles/Oxnard CA webpage and saw a different graphic, dated Oct. 24, 10:24 PM PDT. And perhaps by the time you read this there will be yet another graphic, or perhaps none at all if the santa ana wind event is past.

Here is the special weather statement from the NWS that I referred to earlier:

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
352 AM PDT MON OCT 24 2011

CAZ034>041-044>046-051>054-059-087-088-547-548-250100-
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-VENTURA COUNTY COAST-
LOS ANGELES COUNTY COAST INCLUDING DOWNTOWN LOS ANGELES-
VENTURA COUNTY INTERIOR VALLEYS-VENTURA COUNTY COASTAL VALLEYS-
SANTA MONICA MOUNTAINS RECREATIONAL AREA-
SAN LUIS OBISPO COUNTY MOUNTAINS-SANTA BARBARA COUNTY MOUNTAINS-
VENTURA COUNTY MOUNTAINS-
LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA MONICA RANGE-
ANTELOPE VALLEY-CATALINA ISLAND-SANTA CLARITA VALLEY-
LOS ANGELES COUNTY SAN FERNANDO VALLEY-
LOS ANGELES COUNTY SAN GABRIEL VALLEY-
352 AM PDT MON OCT 24 2011

...MODERATE SANTA ANA WINDS WITH VERY LOW HUMIDITIES EXPECTED
LATE WEDNESDAY THROUGH FRIDAY...

HIGH PRESSURE WILL BUILD INTO THE GREAT BASIN ON WEDNESDAY...
RESULTING IN INCREASING OFFSHORE FLOW OVER SOUTHWESTERN CALIFORNIA
FROM WEDNESDAY AFTERNOON THROUGH THURSDAY. GUSTY NORTHEAST CANYON WINDS ARE EXPECTED THROUGH AND BELOW THE FAVORED PASSES AND CANYONS OF VENTURA AND LOS ANGELES COUNTIES...WHERE SOME AREAS MAY HAVE ADVISORY LEVEL WIND GUSTS BETWEEN 40 AND 50 MPH. BY THURSDAY NIGHT AND FRIDAY...OFFSHORE FLOW WILL PERSIST BUT THE NORTHEAST WINDS WILL NOT BE QUITE AS STRONG.

THE OFFSHORE FLOW WILL IMPORT VERY DRY AIR INTO THE REGION AS WELL.
ON WEDNESDAY...AFTERNOON RELATIVE HUMIDITY WILL FALL IN THE LOW
TEENS AND SINGLE DIGITS ACROSS THE MOUNTAINS. THESE LOW RELATIVE
HUMIDITIES WILL THEN SPREAD INTO THE FOOTHILLS AND VALLEYS ON
THURSDAY AND FRIDAY. THE OFFSHORE WINDS WILL RESULT IN VERY POOR
OVERNIGHT RELATIVE HUMIDITY RECOVERY. THE LOW HUMIDITIES COMBINED
WITH GUSTY CANYON WINDS LATE WEDNESDAY THROUGH FRIDAY MORNING WILL
RESULT IN HEIGHTENED FIRE WEATHER CONCERNS. THERE WILL BE THE
POTENTIAL FOR RED FLAG CONDITIONS DURING THE PERIOD...ESPECIALLY
FOR THE MOUNTAINS OF VENTURA AND LOS ANGELES COUNTIES INCLUDING
THE SANTA MONICA RANGE...AND THE SANTA CLARITA VALLEY. A FIRE
WEATHER WATCH MAY EVENTUALLY BE NEEDED FOR THESE AREAS AS WE
DRAW CLOSER TO THE EVENT.

AS THE OFFSHORE FLOW DEVELOPS...A WARMING TREND CAN BE EXPECTED
WEDNESDAY THROUGH FRIDAY...BUT HOT CONDITIONS ARE NOT ANTICIPATED.
THE MOST NOTICEABLE WARMING WILL OCCUR ON THURSDAY AND FRIDAY WITH
MANY COASTAL AND VALLEY AREAS IN THE UPPER 70S TO MID 80S.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA FOR THE
LATEST UPDATES ON THIS SITUATION.