... pattern so unusual that it has forecasters scratching their heads.

[tabatha]

A series of warm Pacific storms will continue to batter Southern California with strong winds, heavy downpours and snowfall Sunday, according to the National Weather Service.

The wet weather is expected to last through midweek, in a pattern so unusual that it has forecasters scratching their heads — particularly because this is a La Niña year, when ocean temperatures near the equator cool. Such years often involve colder, drier conditions in Southern California, said Bill Patzert, a climatologist for the Jet Propulsion Laboratory in La Cañada Flintridge.

"I call La Niña the diva of drought for Southern California," Patzert said. "But the rainfall looks like El Niño."

As a result, some areas might receive their highest one-week rainfall totals in recent years.

.............

About 2 to 5 inches of rain was expected to fall Sunday in the coastal and valley areas, and 5 to 10 inches in the foothills and mountains, according to Stuart Seto of the National Weather Service. Snow levels are expected to remain above 9,000 feet and then begin to fall by Monday, he added.

.............

Forecasters initially attributed the big rainstorm to a "Pineapple Express," a weather pattern that delivers moisture from the Hawaii area to the Pacific Coast. But the system hammering Southern California is actually caused by a large plume of subtropical moisture that is stretching from Asia. The plume "is mixing with a low-pressure system, and it's creating heavy periods of rain," Seto said.

http://www.latimes.com/news/local/la-me-pineapple-express-20101219,0,7110204.story

[SheilaT]

1. "So unusual that it has forecaster scratching their heads"

just indicates we don't know everything about climate and the mechanisms that influence it.

I am not, by the way, trying to say that global warming isn't real, just that we still have more to learn about how everything works.

[Jackpine Radical]

2. I think stuff like this is actually evidence for GW.

The warming of the Earth is very uneven and unpredictable; it amounts to adding chaotic energy to the system, and generates unpredictable results. In statistical terms, the variance increases much faster than the mean.

[Motown_Johnny]

4. the correct term is "Climate Change"

think about it

[elocs]

7. I wish that "climate change" was the term used from the beginning

because it would have prevented a lot of unnecessary wrangling over the term "global warming". Sure, the deniers would still deny, but "global warming" just made it easy for them.

[Uncle Joe]

12. Global warming is actually the most accurate term to describe the disease, climate change is just

the localized symptoms.

[harun]

14. I think that term has its issues as well. Climate has always had periods of

great change.

Issue is the Carbon levels. So the term used should reflect that. I like The Carbon Flush.

[Bandit]

27. Global Warming is real but only the symptom while the cause is Climate Change.

And the Cause of Climate Change is probably many factors combined with not the least being man's pollution.

[NoPasaran]

3. Wish you could send some of that rain my way

It's dry as a bone in Central Texas. We really haven't had a good soaking since Hermine in September.

[GrannyK]

17. And even that soaking didn't reach those of us who are a little

bit north of the Temple area.

I'm a little south of Moody and we only got a few sprinkles from Hermine. I can't remember when we had a good soaking.

[tabatha]

5. Here is a good place to see the rain over CA

http://www.wunderground.com/radar/radblast.asp?num=6&delay=15&scale=1.00&noclutter=0&ID=VBX&type=N0R&lat=0&lon=0&label=you&showstorms=0&showlabels=1&rainsnow=0

[kestrel91316]

6. We have already had more cold, cloudy, rainy weather here this fall

than we normally get in an average winter (or at least it seems so to me). And winter doesn't start until tomorrow. We had ZERO fire season this year, which is a wonderful thing but highly unusual, and all this rain doesn't bode well for the fire situation once it DOES come back, due to all the growth of chaparral that's gonna build up.

It's raining and raining and raining. The storm fronts settle in for days instead of quickly moving on, which is the norm.

[LWolf]

8. As I recall, it's normal to have lots of rain in an El Nino year.

While I moved out of So Cal 5.5 years ago, I lived there for 30 years; excess rain and resultant flooding came with El Nino.

I'm wondering if El Nino is more, or will be more, frequent with global warming. Will it become the norm?

[kestrel91316]

15. I thought this was a La Nina year. I guess I can't keep track, they change their

minds about it so often. At any rate, I have been here 27 years. This is the dreariest, coldest, wettest fall I can recall.

[LWolf]

18. It's been a wet fall in my area, as well.

Some of that in rain, some in snow. Right now there's 6 inches on snow on the ground, wilth more showers predicted off and on all week. I'm welcoming it, since the snow insulates the ground a bit, and the moisture raises the temperatures a little. The 2 previous years I've had too many sub-zero temps; pipes frozen for days, cutting off all water on the place, pipes breaking....I need to get through this winter without the repair bills, and without having to haul water.

I'm pretty sure it's an El Nino year, but I could be wrong. Then again, climate change or global warming COULD indicate a general warming of the Pacific, and increase in storms, becoming the norm.

[tabatha]

21. You are right - that is why they are scratching their heads.

"particularly because this is a La Niña year, when ocean temperatures near the equator cool. Such years often involve colder, drier conditions in Southern California, said Bill Patzert, a climatologist for the Jet Propulsion Laboratory in La Cañada Flintridge.

"I call La Niña the diva of drought for Southern California," Patzert said. "But the rainfall looks like El Niño.""

[necso]

9. I like using Goes full-disk (west) and composite data

to get a broad view of things.

Here's the infrared (which doesn't require sunlight over the entire area of interest):



Here's the water vapor (composite, incomplete):

http://www.goes.noaa.gov/browsc3.html

There is, has been, a rather persistent, well-developed "plume" of clouds and moisture (according to the data) that's somewhat untypical.

And a jet-stream prediction (which, as a prediction, is an extrapolation):

http://www.weatherimages.org/data/imag192.html

Location, strength and how well-formed it is, are generally of interest.

The current NWS forecast for my area doesn't predict snow in the 7-day, and it predicts a break starting Thursday. Although I'll be interested to see what the forecast is on Monday (which is days away from the coming holiday).

[nadinbrzezinski]

11. Holy shit that is going well beyond the Hawaiian chain

and well into the Western Pacific.

[tabatha]

16. Thanks for that - it illustrates the comment made in the article:

Forecasters initially attributed the big rainstorm to a "Pineapple Express," a weather pattern that delivers moisture from the Hawaii area to the Pacific Coast. But the system hammering Southern California is actually caused by a large plume of subtropical moisture that is stretching from Asia. The plume "is mixing with a low-pressure system, and it's creating heavy periods of rain," Seto said.

[necso]

19. I'm no meteorologist

(and my interest in weather particulars is mostly confined to my location), but the current "tropical fetch" ("pineapple express") does seem somewhat different than more-common patterns of such (whatever you call it).

More generally, the definition of terms (like "Santa Ana" winds) can be subject to some debate; although I'm often content using multiple, even contradictory definitions of some thing, as long as effective communication can take place using these definitions.

[tabatha]

20. Pineapple Express

http://en.wikipedia.org/wiki/Pineapple_Express

I just learned this term yesterday, although it has been around for a while.

This weather is NOT typical "Pineapple Express" weather - but far greater, where the plume does not start in Hawaii but further back in Asia.

[necso]

22. If you're interested in the phenomenon

(warmer, wetter "fetch"), you might want to try to find a good article on the Hawaiian rainbands. (I couldn't quickly find one; plus, I haven't been paying attention to what (if anything) is happening there.)

But it isn't only such "fetch" that affects precipitation, the strength of the storms coming from "up north" and how far down these reach (with strength) is important.

However, any further discussion will likely have me stepping on some orthodoxies, and since I haven't kept data supporting my observations, offering these observations risks more trouble than it seems worth.

[tabatha]

23. coming from "up north"?

[necso]

25. A common pattern for winter storms in SoCal

is to move "down" from the Gulf of Alaska or other points north and west. (You can often follow the progress of these storms on the radar.) And commonly, we get winter storms when the jet-stream moves down towards (over, near) SoCal, as is the case apparently now (there is often a very pronounced recurving (a "loop") in the jet-stream when this happens). (There are also "cut-off" lows that move "down" over us: ie, cut off from the steering influence of the jet-stream; although storms can seem to affect the jet-stream itself (which apparently isn't always well-formed), so there appears to be something of a mutual influence.)

Sometimes there are warmer, wetter influences that get "fetched" ("pulled in") from warmer, wetter regions, which often means the area around Hawaii (hence "Pineapple Express" -- and the term being questionable in these circumstances) .

Right now, there seems to be something of a "conveyor belt" delivering moisture from warmer regions, which appears related to the jet-stream and more-northernly (from here) influences (lingering low pressure). And without these influences, my guess is that the pattern would quickly break down.

[tabatha]

26. Ok, I was concentrating on the current weather activity.

Yep, I am also aware of the Pacific high that allows us to have such normally stable summers.

[WCGreen]

10. maybe it's androgynous Nina....

[glinda]

13. All of this is just the beginning. The Earth's climate is out of whack.

[azul]

24. 40 days and 40 nights rinse cycle?

My wife worked for a while in Noah's workshop:

http://www.ars.usda.gov/Main/site_main.htm?modecode=53-06-20-00