Santa Ana winds ease over Los Angeles

By: Dr. Jeff Masters , 2:17 PM GMT on November 17, 2008

Share this Blog
3
+

The Santa Ana winds have died down over Los Angeles, and winds should remain below 25 mph today through Thursday over the region. This should allow fire fighters to gain control of the three major blazes burning near the city. Wind gusts in excess of hurricane force--74 mph--were recorded at several mountain locations Friday and Saturday, thanks to the major difference in pressure between a strong high pressure system to the northeast of Los Angeles and lower pressure air over the ocean. By 4 pm PST Sunday, though, winds had fallen below 15 mph over the entire region (Figure 1), and a weak sea breeze had formed near the coast. Taking a look at this morning's wundermap (with fire layer turned on) for Los Angeles, we can see that winds are below 5 mph over the region. All high wind warnings and fire weather warnings have been canceled for California, but continued hot and dry conditions will slow down efforts of fire fighters to control the fires. The smoke has caused pollution problems in the city, and the Air Quality Index (AQI) for particulate matter less than 2.5 microns (PM2.5) exceeded the EPA standard yesterday. Today's pollution forecast calls for PM2.5 levels in the unhealthy for sensitive groups level, in excess of the EPA standards.


Figure 1. Wundermap (with fire layer turned on) for Los Angeles, California, at 4 pm EST Sunday November 16, 2008. Two major fires, the Sylmar fire to the north, and the Freeway fire to the east, are shown. The black colors show the relative concentration of smoke. The colored circles show the temperature, and the lines going into the circles show the direction the wind is blowing from. The perpendicular lines at the the end of these lines show how strong the wind is blowing. Each longer line is an additional 10 mph, and each shorter perpendicular line is an additional 5 mph. Thus, for the circle at upper right with a 66° temperature, the wind was blowing 15 mph out of the NNE. (Note that we've changed the convention used on marine maps, where these so-called "wind barbs" denote the winds in knots, not mph).

High temperature records
The hot flow of air off the desert set numerous high temperature records across Southern California on Sunday. Records set or tied included 88° in downtown Los Angeles, 93° in Camalillo; 86° at LAX airport; 90° at Long Beach; 89° at Paso Robles; 87° at Santa Maria; 91° at Woodland Hills; 87° at UCLA; 93° at Oxnard; and 87° at Santa Barbara. On Saturday, 30 high temperature records were set or tied across the state of California, including a blistering 93° in downtown Los Angeles (old record, 90° in 1936). The hottest new record was 94° at the Santa Ana Fire Station.

The forecast
Hot and dry conditions will persist over Los Angeles today, then gradually cool Tuesday and Wednesday. On Wednesday and Thursday, winds should reverse and blow cool, moist air from the oceans over the city, allowing fire fighters to gain full control of the fires. By Saturday, the GFS model is indicating a possible return to Santa Ana wind conditions for the weekend, but the ECMWF model disagrees. At this point, it appears we may get a weak Santa Ana wind event this weekend, but nowhere near as strong as the one that just ended.


Figure 2. Visible satellite image from NASA's Terra satellite taken on Sunday, November 16, 2008 at 11:30 am PST. Smoke from the Sylmar fire 20 miles north of Los Angeles has drifted out over the Catalina Islands, joined by a larger plume of smoke from the "Freeway Fire" in Orange County.

Support the Portlight Christmas for Gulf Coast Kids Honor Walk
The Portlight.org charity is sponsoring a new nationwide grassroots event to raise funds for and awareness of their ongoing efforts, specifically to provide Christmas presents (and maybe a big party) for kids and families in the Gulf Coast areas devastated by Hurricane Ike. They need 100 people across the country to commit to walking one mile this Saturday, November 22, and to raise at least $300.00 in sponsorship from friends, family, co-workers, neighbors, etc. Participants can choose where they want to walk--the local park, the mall, anywhere. Please support this worthwhile effort!

Jeff Masters

Sayre fire (anvilhead)
Sayre fire
Sayre Fire (anvilhead)
Sayre Fire

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 452 - 402

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

pottery....remind me in August that I'm complaining about the cold.....
Member Since: Posts: Comments:
Looks like some of the models are now not showing a winter storm on the East coast until the Monday after Thanksgiving.
Member Since: September 2, 2007 Posts: 178 Comments: 20443
441. conchygirl

Yeah, forcast lows have been way off the last couple nights here (by 10-11 degrees) so I figure tonight I'll probably really get it.
Won't frost here by the lake, but maybe nearby.
Currently 55 but feels diffent tonight.
Member Since: September 2, 2008 Posts: 97 Comments: 32263
440, Thank goodness.
Member Since: Posts: Comments:
Presslord, my eldest just finished a Dive job in SC -- he passed through Charleston -- He loved the place, the people, the architecture.....did say he say some he saw some broad with a cigar in her mouth and huge whatever's banging on doors trying to raise money for Portlight.org
Member Since: July 18, 2007 Posts: 30 Comments: 26536
pottery....you make me sick......
Member Since: Posts: Comments:
wow its cold and windy......
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting presslord:
conchy.....I'm freezin' in Charleston....
Ah, poor guy!
Member Since: June 11, 2008 Posts: 24 Comments: 5910
Cold and bored ?
I agree with that. Its 76 here. Got on my shirt..
Member Since: Posts: Comments:
But Presslord, just think of all the donations --
Member Since: July 18, 2007 Posts: 30 Comments: 26536
conchy.....I'm freezin' in Charleston....
Member Since: Posts: Comments:
Ok, who has a decent topic to discuss. Weather doesn't seem to be doing it, although it is gonna be really nippy here in Central Florida tonight! Rob - your area might see frost.
Member Since: June 11, 2008 Posts: 24 Comments: 5910
I am NOT going to wave my Jolly Roger in public!!!!!!!!
Member Since: Posts: Comments:
OOOOOOOOhhhhhh, sculls and crossbones waving about in the car. I gotta see that....
Member Since: Posts: Comments:
Quoting zoomiami:
Evening everyone - quite lively in here tonight. Cold weather stirred everyone up!
Hey Zoo - just like Surfmom's ponies - cold weather does gets them all 'excited'.
Member Since: June 11, 2008 Posts: 24 Comments: 5910
Hey, Tim!

as you can see, we're all cold and bored and desperately seeking an appropriate topic.
Member Since: September 2, 2008 Posts: 97 Comments: 32263
Evening everyone - quite lively in here tonight. Cold weather stirred everyone up!
Member Since: Posts: Comments:
Quoting RobDaHood:
I'm just gonna sit back and behave myself tonight...keeping mouth shut.
Me too, but missed most of the mischief! :)
Member Since: June 11, 2008 Posts: 24 Comments: 5910
Quoting conchygirl:
Whoa........just jumped in and looks like I have some catching up to do - Surfmom, are you instigating again. LOL
It's been a while, but I have it under cotnrol...well sorta -- instead of the sword you could wave The JoLLy Roger - might be more appropriate
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Greetings, Tampa. What news ??
Member Since: Posts: Comments:
Quoting presslord:
in the chat while in the car on the way tomorrow....I will be happy to respond to this 'sword flashing' business....


Yikes.....
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Good evening everyone.
Member Since: September 2, 2007 Posts: 178 Comments: 20443
I know -- but we're all thinking it LOL -- Okay, I am calmed down now -- back in lady like mode
Member Since: July 18, 2007 Posts: 30 Comments: 26536
in the chat while in the car on the way tomorrow....I will be happy to respond to this 'sword flashing' business....
Member Since: Posts: Comments:
I got a New Gig for the Mardi Gras Monkey..Link

Member Since: Posts: Comments:
Quoting RobDaHood:
Waiting for Astro to follow that link...the reaction is always fun
Scared him away!!
Member Since: Posts: Comments:
I'm just gonna sit back and behave myself tonight...keeping mouth shut.
Member Since: September 2, 2008 Posts: 97 Comments: 32263
OK - back to business - questions... you are taking Portlight to Atlanta? are we chattering to keep you company or do we need to keep it straight and promote what Portlight has accomplished?

BTW -- IT'S SO GOOD TO SEE YOU PRESSLORD!!!! thought you sailed away to another port and found some other pyrate dames to talk weather with
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Whoa........just jumped in and looks like I have some catching up to do - Surfmom, are you instigating again. LOL
Member Since: June 11, 2008 Posts: 24 Comments: 5910
I cannot think of a Press response to you Mom, that would not result in a permanent, immediate bannishment. LOL
Member Since: Posts: Comments:
brrrr..floor furnace is cranky.
Need new thermostat in the am.

Home Depot run in order.

Maybe upgrade to Digital.

Join the 21st Century.
Member Since: Posts: Comments:
the only appropriate response to that would very likely get me banned for life....
Member Since: Posts: Comments:
428 - they might be warm Presslord, but the sword is HOT
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Quoting presslord:
Please let the record show:

I am NOT taking the bait by responding to the 'sword flashing' comment...
....awww come on....you'd have the girls of wu howling
Member Since: July 18, 2007 Posts: 30 Comments: 26536
right now I'm just thinkin' they'd be warm....
Member Since: Posts: Comments:
post 410. Oh come on Press.........
Member Since: Posts: Comments:
nice Pat....you da man....
Member Since: Posts: Comments:
Quoting presslord:
they were also, as a matter of fact, anatomically correct....
..... hate to see 'em in another 5 years or so.... might be dusting the floor w/'em
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Quoting presslord:
Greetings all.....stormjunkie and i are travelling to Atlanta tomorrow to make a presentation about our Ike efforts to a coalition of federal and state agencies....you can follow us by webcam at stormjunkie.com Very cool!
Member Since: Posts: Comments:


Keep on Truckin press...Link
Member Since: Posts: Comments:
Waiting for Astro to follow that link...the reaction is always fun
Member Since: September 2, 2008 Posts: 97 Comments: 32263
Plastic boobies ?? I thought they wer.............
Boy, am I silly......
Member Since: Posts: Comments:
Please let the record show:

I am NOT taking the bait by responding to the 'sword flashing' comment...
Member Since: Posts: Comments:
Quoting presslord:
THEY WERE NOT PLASTIC!!!!!!!!!!!!

They were down-filled.....
ROTFL --now I have heard everything.......
Member Since: July 18, 2007 Posts: 30 Comments: 26536
they were also, as a matter of fact, anatomically correct....
Member Since: Posts: Comments:
leave the treat to the real ladies
Member Since: July 18, 2007 Posts: 30 Comments: 26536
THEY WERE NOT PLASTIC!!!!!!!!!!!!

They were down-filled.....
Member Since: Posts: Comments:
Thats brilliant, Press.
Member Since: Posts: Comments:
Quoting presslord:
Astro....check the archives just before Halloween....you're in for a real treat....
more like a cheap trick Presslord
Member Since: July 18, 2007 Posts: 30 Comments: 26536
and please Presslord, not to conflict with your staff, but the next time you get dressed up? -- can we have a Pirate Captain look -- some of us would prefer the image of you flashing your sword instead of a cigar and plastic boobies
Member Since: July 18, 2007 Posts: 30 Comments: 26536
pottery...yea....they asked us to give the keynote....gonna shake 'em down for some $$$$$$$$$$
Member Since: Posts: Comments:

Viewing: 452 - 402

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.