California fires fueled by record drought

By: Dr. Jeff Masters , 1:40 PM GMT on October 23, 2007

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An area of disturbed weather has developed near the northern Lesser Antilles Islands, due to a westward-moving tropical wave interacting with an upper-level low. Wind shear is currently too high (30 knots) to allow development of this disturbance. However, the past two runs of the NOGAPS model have predicted that wind shear will fall enough by Friday to allow a tropical depression to form near the western Bahamas. This storm is predicted to move westward across eastern Cuba and into the Western Caribbean. The GFS model does not go along with this scenario, but hints at a weak system developing and moving northeast out sea over the middle Atlantic. The UKMET and ECMWF models do not develop a Bahamas storm, either, but do show a large region of low pressure with low wind shear developing over the Western Caribbean later this week. It would not be a surprise to see a tropical depression develop in the Western Caribbean late this week or early next week.

Southern California's fire storm
Surface maps show a strong high pressure system centered over Nevada and Utah. The clockwise flow of air around this high is driving strong northeasterly winds over Southern California. As the air spills down the mountain passes into coastal San Diego and Los Angeles, gravity helps accelerate the winds. The air compresses and warms as it descends, due to the higher pressures found at sea level. This creates a very hot, low-humidity wind--the dangerous Santa Ana wind. At 1:37 pm PDT yesterday, the humidity in downtown Los Angeles was 8%. Some wind reports Monday afternoon in Southern California, showing the strength of the Santa Ana winds:

Los Angeles County peak wind gusts
------------------------------------------------- --
Leo Carrillo Beach... ... ... ... ... ... ... Northeast 44 mph.
Van Nuys... ... ... ... ... ... ... ... ..... North 39 mph.
Tonner Canyon... ... ... ... ... ... ... .... Northeast 46 mph.
Malibu Canyon... ... ... ... ... ... ... .... Northeast 41 mph.
Malibu Hills... ... ... ... ... ... ... ..... North 54 mph.
Newhall... ... ... ... ... ... ... ... ... .. Northeast 38 mph.
Newhall Pass... ... ... ... ... ... ... ..... North 72 mph.
Saugus... ... ... ... ... ... ... ... ... ... North 60 mph.
Del Valle... ... ... ... ... ... ... ... .... Northeast 50 mph.
Acton... ... ... ... ... ... ... ... ... .... Northeast 45 mph.
Camp Nine... ... ... ... ... ... ... ... .... North 71 mph.
Chilao... ... ... ... ... ... ... ... ... ... Northeast 55 mph.
Mill Creek... ... ... ... ... ... ... ... ... North 41 mph.
Sandberg... ... ... ... ... ... ... ... ..... East 40 mph.
Warm Springs... ... ... ... ... ... ... ..... East 62 mph.
Whitaker Peak... ... ... ... ... ... ... .... North 48 mph.
Lake Palmdale... ... ... ... ... ... ... .... Northeast 46 mph.
Poppy Park... ... ... ... ... ... ... ... ... East 43 mph.
Saddleback Butte... ... ... ... ... ... ..... East 33 mph.
Lancaster... ... ... ... ... ... ... ... .... East 31 mph.

Ventura County peak wind gusts
--------------------------------------------
Oxnard... ... ... ... ... ... ... ... ... ... East 41 mph.
Camarillo... ... ... ... ... ... ... ... .... Northeast 51 mph.
Point Mugu... ... ... ... ... ... ... ... ... Northeast 43 mph.
Piru... ... ... ... ... ... ... ... ... ..... North 49 mph.
Simi Valley... ... ... ... ... ... ... ... .. Northeast 41 mph.
Thousand Oaks... ... ... ... ... ... ... .... North 42 mph.
Laguna Peak... ... ... ... ... ... ... ... .. Northwest 62 mph.

Fourteen large wildfires have developed spanning seven counties in California since Saturday, thanks to the Santa Ana winds, and the prevailing extreme drought conditions. Rainfall in San Diego has been a mere 2.6 inches thus far in 2007, 32% of normal. The July 1, 2006 through June 30, 2007 period was the 4th driest on record in San Diego. In Los Angeles, it was the driest year since record keeping began 130 years ago. Downtown Los Angeles has recorded just 3.37" of rain thus far in 2007--only 28% of normal.

Air quality
Not surprisingly, air quality due to particulate matter has been awful in Southern California (Figure 1). Exceedances of the Federal air quality standards by more than a factor of two have occurred the past three days in both Los Angeles and San Diego. Hightened particulate pollution is strongly correlated with increased death rates, particulary in vulnerable populations, such as those with heart conditions, athsma, or other lung diseases. Everyone should avoid any outdoor exertion; people with respiratory or heart disease, the elderly, and children should remain indoors. Keep your windows and doors closed unless it is extremely hot inside. In these cases, seek alternate shelter. Run your air conditioner if you have one. Keep the fresh air intake closed and the filter clean to prevent bringing additional smoke inside. EPA's Airnow website has more information.


Figure 1. Visible satellite images taken midday on Saturday, Sunday, and Monday. Overlaid on the images is the peak daily particle pollution Air Quality Index (AQI) levels due to smoke. Poor air quality became more widespread across the region as the number and size of the fires increased from day to day. Smoke is visible as white or bluish-white streaks. Blowing dust (brown streaks), reducing visibility under three miles, is also apparent on the images. Image credit: NASA and EPA.

The forecast
The warm, dry, and windy weather will continue today, bringing a repeat of yesterday's extremely dangerous fire situation. A trough of low pressure is expected to move into northern California Wednesday morning, weakening the high pressure system driving the Santa Ana winds. By Thursday, the Santa Ana winds will be gone, and fire fighters will be able to gain the upper hand.

This may only be the first of several serious fire situations in Southern California in the coming months. Santa Ana winds conditions commonly develop during the October through March period, and the extreme drought conditions in Southern California are not going to improve until at least December, when the winter rainy season typically starts. The 3-month precipitation forecast from NOAA's Climate Prediction Center calls for a 33% chance of below-average rainfall over Southern California for the coming winter.

The University of Wisconsin's CIMSS group has a more detailed blog with many weather maps and satellite animations of the Southern California fires.

San Francisco's Climate Challenge
San Francisco residents have a different and more positive kind of challenge this week. An innovative contest designed to encourage residents to reduce energy usage is being launched, with a sign-up deadline of Wednesday. The content offers prizes up to $5000 for those residents able to reduce their energy consumption the most over the coming month. For more information, see the new Weather Underground climate page: at http://www.wunderground.com/climate/. The new page will track current climate trends each month, and feature stories on new research and programs in the climate change field every few weeks. We'll also add a full set of information on the science of climate change over the coming months. The goal is to have a web site that keeps track of the most important issues in climate change.

Jeff Masters

Effect the winds in this truck! (chentetij)
Volcadura de un trailer por los vientos de Santana
Effect the winds in this truck!
Smoke over Woodbridge (wheels)
A fire east of Irvine produced major air polution
Smoke over Woodbridge

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258. Drakoen
11:48 PM GMT on October 23, 2007
Nothing over the bay of campeche, just a strong cold front.
Member Since: October 28, 2006 Posts: 57 Comments: 30222
257. Weather456
7:48 PM AST on October 23, 2007
2 Week Satellite Precipitation Accumulation ending 0000Z today reveals several climatological features

Image 08

Mid-Latitude Systems - lighter rainfall amounts and gaps due to the fact they move faster than tropical features due to the westerlies they are embedded within. there are gaps becuz most the mid-latitudes follow a trough-ridge-trough-ridge pattern both in the upper and lower atmosphere. In the lower atmosphere troughs bring rain, ridge brings fair weather. In the upper levels troughs bring cooler weather and ridges bring warmer weather. Usually, a cold front is replaced by a surface anticyclone with a capping upper trof. This is not always the case though, as i have seen "thick" and "tall" ridges from the surface to 200mb.

Temporal Storms of Central America - Tropical and Non tropical rainfalls from daytime heating, sea breeze, upper level lows, the ITCZ, tropical waves. These are some of the heaviest rainfall amounts and likely due to effects of the topography. Most likely areas of flooding also.

Tradewind Inversion markes the lower boundary of the subtropical ridge where the subsidence and mid-upper level dry air in the subtropical ridge creates an inversion limiting cloud cover within the tradewinds.

ITCZ, monsoon trough and the NECZ (near-equatorial convergence zone of N South America) is a convergence of east hemispheres easterly trades. The rainfall pattern here is heavy and more concentrated within narrow band due the fact the clouds are nearly stationary and more intense.



Image 09 is similar but the subtropical ridge and ITCZ is more intense in the Eastern ATL.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
256. Ivansvrivr
11:43 PM GMT on October 23, 2007
Agreed Shen. Politics arent for the main blog. This is neutral ground where we discuss current conditons mainly tropical. We are each given a private blog where we can discuss other interests, but EVERYBODY please kep it off the main. Politics is notthing but TROLL CHUM. thanks.
255. SomeRandomTexan
6:47 PM CDT on October 23, 2007
as long as la nina doesnt mess up opening day of deer season.... i dont care after that...lol
Member Since: August 30, 2007 Posts: 0 Comments: 1837
254. Drakoen
11:47 PM GMT on October 23, 2007
voriticty maximum northeast of the Lesser Antilles.
850mb vorticity:
Member Since: October 28, 2006 Posts: 57 Comments: 30222
252. TampaSpin
11:41 PM GMT on October 23, 2007
246. ShenValleyFlyFish 11:33 PM GMT on October 23, 2007
Sulli/weather et all: Please stop trying to beg the question of the causes of the California disaster. There are a myriad factors including the lunatic fringe in a nation of 250 mil+. If this were coming form the other side of the isle it would have been shouted down long ago. SHAME SHAME


Shen--Ahmen...Bravo..How true.
Member Since: Posts: Comments:
251. Ivansvrivr
11:43 PM GMT on October 23, 2007
Drak, this time of year, that should be off the Belize/Honduras coast. This La Nina is turning into a doozy.
250. presslord
11:43 PM GMT on October 23, 2007
Shen: VERY nicely done....
Member Since: August 13, 2007 Posts: 0 Comments: 10484
249. Drakoen
11:41 PM GMT on October 23, 2007
Member Since: October 28, 2006 Posts: 57 Comments: 30222
247. weatherbro
11:39 PM GMT on October 23, 2007
Models keep on flip-flopping on if and when the front will arrive. This stalling out scenario is highly unusual for October. defiantly La Nina. So if you just moved here don't think every October is like this in Florida lol.
Member Since: May 26, 2007 Posts: 47 Comments: 1287
246. ShenValleyFlyFish
11:33 PM GMT on October 23, 2007
Sulli/weather et all: Please stop trying to beg the question of the causes of the California disaster. There are a myriad factors including the lunatic fringe in a nation of 250 mil+. If this were coming form the other side of the isle it would have been shouted down long ago. SHAME SHAME
Member Since: September 9, 2007 Posts: 36 Comments: 4687
245. presslord
11:32 PM GMT on October 23, 2007
furthermore...even in cases where human activity played a role in ignition...it's not necessarily "arson'...much more often it's careless smoking, improperly extinguished campfires, trash burning, etc.
Member Since: August 13, 2007 Posts: 0 Comments: 10484
244. SomeRandomTexan
11:24 PM GMT on October 23, 2007
Does anyone know how close these fires are to the metro area?
Member Since: August 30, 2007 Posts: 0 Comments: 1837
243. presslord
11:19 PM GMT on October 23, 2007
for the record: The Malibu fire was NOT started by an arsonist...it was caused by wind blowing power lines down....
Member Since: August 13, 2007 Posts: 0 Comments: 10484
242. ShenValleyFlyFish
11:15 PM GMT on October 23, 2007
238. Orcasystems 6:59 PM EDT on October 23, 2007 I don't understand this.. the largest waterbombers (Mars) in the world are a couple hours flying time (Vancouver Island BC) away from California, and no one has asked for them?
I know they are on standbye if asked, it was on the news last night.

AH my dear Canadian cousin do you not understand or are you bewildered by what you understand. (Father was card -green- carrying Canadian). Individualism and hubris will be the demise of this Nation. Sad but when you're #1 you can't ask for help. Would appear like weakness.
Member Since: September 9, 2007 Posts: 36 Comments: 4687
241. weatherblog
11:14 PM GMT on October 23, 2007
This tropical wave encountering the ULL seems likely to develop at this point. The convection is currently strong and shear may not be all too favorable, but is supported by most models that this will let up (obviously being that they all develop it). When, where, and how strong this gets is fully up to debate though. I think the biggest threat of this system, development or no development, would be Northern Anitilles, Puerto Rico, Dominician Republic/Haiti, Cuba, Bahamas, and South Florida. And of course this all matters on how the ULL and the high sets up...which is too questionable to decide now, as the models still don't have a good grip on this system yet.

I'd imagine tonight or tomorrow this will be labeled our new invest.
Member Since: July 10, 2006 Posts: 27 Comments: 1623
240. sullivanweather
11:12 PM GMT on October 23, 2007
Let's not fool ourselves here.

Record drought is playing a hand with the SoCal fires, but most of these fires would have never came to be if not for the arsonists that started them.

There's no doubt that the cause of these fires will eventually be labeled as 'climate change' due to global warming, but anyone with half a brain knows the real problem here is arsonists taking advantage of the weather conditions.
Member Since: March 8, 2007 Posts: 273 Comments: 12612
239. GBlet
11:06 PM GMT on October 23, 2007
Eagle, really? Live in Great Bend. I am looking for some longrange forecasts for my area.
Member Since: September 13, 2007 Posts: 0 Comments: 435
238. Orcasystems
10:59 PM GMT on October 23, 2007
I don't understand this.. the largest waterbombers (Mars) in the world are a couple hours flying time (Vancouver Island BC) away from California, and no one has asked for them?

I know they are on standbye if asked, it was on the news last night.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
237. TerraNova
10:59 PM GMT on October 23, 2007
Interesting system east of Antilles...shear will have to fall though for any development to occur. Apparently this is supposed to occur and every model (including 12z Euro and 18z GFS) develop this to some extent. A very clearly defined circulation can be seen on IR, WV and VIS imagery and I think it's very likely we will have a new invest by tomorrow.
Member Since: July 30, 2007 Posts: 76 Comments: 4063
236. Cavin Rawlins
10:52 PM GMT on October 23, 2007
Afternoon terra

Member Since: July 24, 2005 Posts: 407 Comments: 19076
235. Ivansvrivr
10:52 PM GMT on October 23, 2007
O2AN702AF feel free to e-mail my answer for winter storms to Terra-Nova if you so choose.
234. Ivansvrivr
10:48 PM GMT on October 23, 2007
My avatar is a zoo animal, thats why I was wondering. With the strong A/B high, cold air trying to undercut it in your area, sleet/ice storms are on the menu this winter for lots of areas. Remember 99 or 00 how many people missed the Superbowl due to ice. La Nina.
233. eaglesrock
10:42 PM GMT on October 23, 2007
Searching through the long-range meteograms and found this...a sleet storm for Kansas City.

232. zoomiami
10:42 PM GMT on October 23, 2007
No- its what we call our house/family - too many kids, birds, dogs, cats, fish & other assorted animals!
Member Since: August 13, 2007 Posts: 10 Comments: 4151
231. TerraNova
10:42 PM GMT on October 23, 2007
Can anyone explain to me why here in the northwest, when we have a windstorm, they refuse to call the hurricanes?

Most likely because those systems are extratropical in nature. Waters are too cold to support tropical systems such as hurricanes.
Member Since: July 30, 2007 Posts: 76 Comments: 4063
230. Ivansvrivr
10:38 PM GMT on October 23, 2007
ZooMia do you work at the zoo?
229. TerraNova
10:38 PM GMT on October 23, 2007
Afternoon extreme, 456, drak, and others.

Fires rage in California (Link to full-sized image):

Member Since: July 30, 2007 Posts: 76 Comments: 4063
228. Ivansvrivr
10:36 PM GMT on October 23, 2007
Heat index was like 93 or 94 today here.
227. Ivansvrivr
10:35 PM GMT on October 23, 2007
SEFL-no frontal passage for next 7 days min. Possible heavy rain from stalled fronts though. 1024mb high is a brick wall. Look at the "strong front" in the GOM. Stopped dead in it's tracks. Some models retrograde it by weeks end.
226. zoomiami
10:34 PM GMT on October 23, 2007
The cold front isn't going to make it here (miami) sort of stopped where it is - Reports call for se winds all week (too bad!)
Member Since: August 13, 2007 Posts: 10 Comments: 4151
225. SomeRandomTexan
10:33 PM GMT on October 23, 2007
well no frost here yet but we did see the 40's last night with high in the upper 50's to low 60's.... thats perfect in my book.... wish it was like this all year long....:)
Member Since: August 30, 2007 Posts: 0 Comments: 1837
224. Cavin Rawlins
10:31 PM GMT on October 23, 2007

I should have clarified cold front as compared to COLD FRONT. a cold front makes it as far S. as maybe the fl straits lasts a day before retreating as a warm front. A COLD FRONT sweeps through S. Fl and we at least get a light frost inland/north of Lake O.


ok
Member Since: July 24, 2005 Posts: 407 Comments: 19076
223. Ivansvrivr
10:30 PM GMT on October 23, 2007
I wouldnt say no cold fronts, but weaker ones. There's a cold front heading for FL right now.

I should have clarified cold front as compared to COLD FRONT. a cold front makes it as far S. as maybe the fl straits lasts a day before retreating as a warm front. A COLD FRONT sweeps through S. Fl and we at least get a light frost inland/north of Lake O.
222. SomeRandomTexan
10:30 PM GMT on October 23, 2007
seems the local mets are calling for a barage of cold fronts coming down... in setx
Member Since: August 30, 2007 Posts: 0 Comments: 1837
221. Cavin Rawlins
10:26 PM GMT on October 23, 2007
Ivansvrivr,

I wouldnt say no cold fronts, but weaker ones. There's a cold front heading for FL right now.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
220. Cavin Rawlins
10:25 PM GMT on October 23, 2007
199. Patrap 5:41 PM AST on October 23, 2007

That fire image looks like a pic of early Earth.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
219. Ivansvrivr
10:24 PM GMT on October 23, 2007
456, thats why SFL won't get a cold front until maybe christmas, Then we get icicles when we spray water on our roofs the night of the freeze. I did in 85. La Nina dams polar air up north until mid-winter. When the dam breaks, Fl Citrus dies.
218. Cavin Rawlins
10:19 PM GMT on October 23, 2007
217. Ivansvrivr 6:18 PM AST on October 23, 2007 Hide this comment.
"A 1024 mb ridge centered near 33N/62W is the dominate weather feature over the Western Atlantic"

Isn't that high at least as strong as the typical A/B high in Aug/Sept?


yes
Member Since: July 24, 2005 Posts: 407 Comments: 19076
217. Ivansvrivr
10:18 PM GMT on October 23, 2007
"A 1024 mb ridge centered near 33N/62W is the dominate weather feature over the Western Atlantic"

Isn't that high at least as strong as the typical A/B high in Aug/Sept?
216. Ivansvrivr
10:12 PM GMT on October 23, 2007
With the Bermuda High so stong, La Nina raging, wierd pattern, CONUS is in fall mode, Tropics are just getting into September. W.Carrib topography is condusive for development when tradewinds die down. Bermuda high not exactly retreating, trade winds may be slow to weaken.
215. Drakoen
10:12 PM GMT on October 23, 2007
yea Adrian. The system can take advantage of the conditions. We'll have to watch this one closely.
Member Since: October 28, 2006 Posts: 57 Comments: 30222
214. Cavin Rawlins
10:10 PM GMT on October 23, 2007
Whats left of Kiko

Member Since: July 24, 2005 Posts: 407 Comments: 19076
213. hurricane23
10:03 PM GMT on October 23, 2007
If the 18z CIMSS are on the money conditions could become more favorable for some development of the low north of the islands.
Member Since: May 14, 2006 Posts: 8 Comments: 13741
212. Cavin Rawlins
10:00 PM GMT on October 23, 2007
CENTRAL AMERICA AND THE CARIBBEAN REGION....

An area of cloudiness is located within the Southwest Caribbean Basin from Central America to 70W south of 18N. This area is associated with a 1009 mb low near 12N/79W and the ITCZ/monsoon trough. Otherwise, dry air and pretty fair weather dominates the Greater Antilles and elsewhere across central America.

Overcast skies, shower, increase wind and wave activity will continue to affect the Lesser Antilles north of Saint Vincent (near 15N) in association with a tropical wave near 62W south of 22N interacting with southwesterlies aloft south of an upper circulation near 20N/60W. Latest visible imagery showed rotation near the surface which indicate a low pressure area however, upper level winds are currently unfavorable for development but expected to relax somewhat as it moves towards the west near 5-10 knots.


by W456
Member Since: July 24, 2005 Posts: 407 Comments: 19076
211. Patrap
9:57 PM GMT on October 23, 2007
GOES-12 Channel 3 (WV) False Color

Link
Member Since: July 3, 2005 Posts: 423 Comments: 127814
210. O2AN702AF
9:56 PM GMT on October 23, 2007
Can anyone explain to me why here in the northwest, when we have a windstorm, they refuse to call the hurricanes? Lets see, they blow counter-clockwise with winds up to 100 plus? Why is that just a storm? I love the gulf and someday are leaving this cold damp place. Perhaps it is because on the coast all there is are trees and no one cares about them. by the time the storm gets 100 miles inland to civilization it only blowing 60 to 80??? Just curious. Can't wait to move to Galveston.!!!
209. Patrap
9:55 PM GMT on October 23, 2007
GOES-12 Channel 4 (IR) Atlantic

Link
Member Since: July 3, 2005 Posts: 423 Comments: 127814
208. Patrap
9:54 PM GMT on October 23, 2007
GOES WV Loop of Tropical Basin


Link
Member Since: July 3, 2005 Posts: 423 Comments: 127814

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

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