WunderBlog Archive » Weather Extremes

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

California: Waiting for El Nino

By: Christopher C. Burt, 10:02 PM GMT on December 09, 2015

California: Waiting for El Nino

The title should read ’Waiting for El Nino-enhanced precipitation’ to affect the state since this, so far, has yet to occur. However, hopefully this will be the last blog I write for a while concerning how dry California has been these past years: a series of storms are now taking aim at the state and, perhaps, the beginning to the end of California’s drought nightmare is at hand. Nevertheless, there is an item of concern: previous strong/very strong El Ninos brought heavy early season rain and snow to the state during their respective Novembers. This has not happened this time around. Here are the details.

As we approach mid-December it is finally appearing that the much anticipated heavy rain and snowfalls that normally affect California during strong/very strong El Ninos are beginning to take shape. Until now the jet stream has been funneling storm after storm into the Pacific Northwest (where flooding is now happening but, so far, only relatively light rain/snow has fallen in California (for the most part).

Although it is said that the ‘real’ affects of strong El Ninos (precipitation-wise) normally do not begin in California until January this is not true. In fact, if we look at the historical record, November also usually sees much above normal precipitation in California during strong/very strong El Nino events whereas Seattle (as an example for the Pacific Northwest) sees below average precipitation. The reverse occurred this year. Let’s take a look at the past six times since 1950 that a strong/very strong El Nino developed and how much actual precipitation was measured during the Novembers of those years in Seattle, San Francisco, and Los Angeles.



The graph above shows the Oceanic Nino Index since 1950. The winter seasons that experienced strong/very strong El Ninos were those of 1957-1958, 1965-1966, 1972-1973, 1982-1983, 1997-1998, and, of course, this season of 2015-2016. Graph by Jan Null of Golden Gate Weather Services using data from NOAA/CPC.

Now let’s look at how much rain fell during the Novembers of those years in Seattle, San Francisco, and Los Angeles (and what the 30-year November precipitation normals are).



As we can see, this past November was an anomaly with much below average precipitation in SF and LA and much above average in Seattle. No previous strong/very strong El Nino (since 1950 at least) has seen this happen (except for November 1957 in the Los Angeles case). Obviously, this time around the El Nino seasonal precipitation pattern has not commenced in a similar way (as in former El Ninos). Does this mean that this season’s El Nino (currently on track as one of the strongest on record) will be a bust for California? I doubt this and remain optimistic that the state will see exceptionally heavy precipitation as the coming weeks and months progress. The slow start is most likely a result of other factors not directly related to El Nino. I hope.

Where California Stands Precipitation-wise as of December 9th

As of the time I write this, the precipitation season (which begins on July 1st) and the calendar year-to-date precipitation has been exceptionally deficient almost statewide. Snow/water content is around 60% of normal for this time of the season in the Sierra Nevada and the state’s reservoirs are at just 51.5% of normal capacity for the time of year.





Snow/water content in the Sierra Nevada (top map) and reservoir capacity for the state as of December 8th. Both graphics courtesy of the California Department of Water Resources.

In so far as individual cities are concerned, it remains the driest calendar year on record for San Francisco, Redding, and Blue Canyon (located in the central Sierra at around 5,000’ elevation). Only southern California has seen above normal or close to normal precipitation, this a result of some unusually heavy rains in the July-September period when dissipating tropical storms and a very active monsoonal season affected much of the Southwest. San Francisco’s paltry 4.78” since January 1st (as of December 9th) is especially remarkable since it was just two years ago that the previous driest year on record occurred with a 5.59” total in 2013. San Francisco’s precipitation period of record (POR) dates back to 1849 and is one of the longest such for any city in the U.S. That being said, it is almost certain an additional .81” will fall by the end of the month if not in the next few days. Nevertheless, this year does have a shot at of becoming the 2nd driest year on record. That feat is currently held by 1917 when 9.00” was measured.





Precipitation for select Californian cities/towns so far this season (since July 1st) top table and so far this calendar year (bottom table) as of December 9th.

I suspect the figures in the above tables will look quite different by the end of this month!

For a deeper analysis of the California weather/climate situation you can do no better than to follow The California Weather Blog by Daniel Swain.

Christopher C. Burt
Weather Historian

Extreme Weather El Nino Precipitation Records

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Very nice El Nino blog. I know it has really been dry in SoCal this fall but I thought further north was doing better. I wonder if the overall world heating is causing some unusual behavior for El Nino. I am hoping we can at least get up to 'normal' rain this time.
Thanks for the excellent coverage of the peculiarities of this El Niño, Christopher. I think a "typical El Niño" and a unicorn are the same animal.
Peru downgrades El Nino forecast from 'strong' to 'moderate' What do you think about this Mr. Burt?

The headline is a little misleading---the text of the article says that Peru has reduced the chances of a strong El Nino impact there from 50% to 35%
Great read, thanks for the info.
Great piece of work. But bad news indeed. The Nino is not having the hoped effect to relieve the catastrophic California's drought.
It would be useful to see an analysis of the precipitation in following months during past Nino events, after the Nino had peaked up and during the post-Nino and the transition to the Nina.
I guess time to is running out. We have few months until May to try to fill up those reservoirs at acceptable levels.
Thanks for the update Chris... always enjoy the blog.

We saw a similar situation in southern Australian during the 2010-11-12 La Nina sequence. While summer half year rainfall was excellent, the cool seaon rainfall in the westerly climate regions (the south) wasn't great.




From Santa Rosa and a long time resident retired scientist:

Strangest weather year of the past decade. Five to six water-laden storms with tropical characteristics have passed through since 1NOV without appreciable precipitation on our scale of previous EN's. Heavy clouds moving normally across coast range are misty, not rainy; i.e., very poor drop formation with high density of very small droplets. The jet stream maps show very extended, contiguous contours reaching from CA westward across Japan, China and on to Europe...very unusual. Yet, the GOES Water Vapor images give evidence for heavy total water vapor passing over Northern California a frequent intervals. Could the high levels of pollution and atmospheric particulates in China (and Japan and Korea be dumping CA's precipitable water content before the storms reach CA?
This is as interesting as it is ominous ; I got a feeling it will always "rain in southern California"
@Caribguy:
In the last 30 days, the PW didn't fall down westward from California, but rather on Oregon, Idaho and Washington.
Link
Aside from that, global precipitation patterns look like what you would normally expect from an El Nino event.
Link
We still have hope. If memory serves me, during the early 90s drought, the "March Miracle" filled the Monterey, CA reservoir from 5% to capacity in a single month.
The current superstorm in the Alaskan waters brought a new record yesterday:
It looks like we have a new record for the strongest sustained wind in Alaska, as in Adak a wind speed of 95 mph was recorded.
Adak
According to your research, the old record is 93 mph from 25th Februrary in 1951 in Kotzebue.
The wind gust record of 159 mph from December 7th in 1950 on Attu Island was not broken. However, St. George came close with 156 mph.
St. George
Super Extra-tropical Storms
Indeed, the Adak data has been confirmed to be accurate by Rick Thoman of NWS-Fairbanks (the go-to-guy for Alaskan weather records). However, he tells me that the St. George wind gusts were erroneous.

Quoting 11. ChateauChalon:

The current superstorm in the Alaskan waters brought a new record yesterday:
It looks like we have a new record for the strongest sustained wind in Alaska, as in Adak a wind speed of 95 mph was recorded.
Adak
According to your research, the old record is 93 mph from 25th Februrary in 1951 in Kotzebue.
The wind gust record of 159 mph from December 7th in 1950 on Attu Island was not broken. However, St. George came close with 156 mph.
St. George
Super Extra-tropical Storms
Quoting 12. weatherhistorian:

Indeed, the Adak data has been confirmed to be accurate by Rick Thoman of NWS-Fairbanks (the go-to-guy for Alaskan weather records). However, he tells me that the St. George wind gusts were erroneous.




Thanks for the fast response! I thought, the gusts were caused by strong turbulence due to orographic effects. The ratio of gusts to sustained winds in St. George reminds me that of cyclone Olivia in Australia in 1996, a category 4 cyclone and according to WMO the world record holder with 408 km/h. The next highest gusts, during this storm, were 267 km/h and 257 km/h. Olivia
Post before this on 'incredible November warmth'.
Well, I don't know what 'incredible' means anymore.

December average minimum temp in Holland is running above the average daily temp of December 1974 which is the warmest in the record.
This December average will smash that record by two degrees.
April normal average last century until the 1980's, 8.0%uFFFD C
April normal average today (1981-2010), 9.0%uFFFD C.
Projected December 2015 average, 9.3%uFFFD C.
Dutch climate: mediterranean...

Edit 17th: projected average now 9.7 C.

Looking back at past weather is like looking back at the stock market and expecting to predict the future. You can't say that climate change is here and then look back in the past when climate change was sorta here and expect to discover some repeat patterns. I have come to learn that the weather is what is over my head not what stats/predictors say it is. My collected rainfall amount has NEVER matched the "precipitation amounts recorded" once this year.
Quoting 16. AGalanks:

Looking back at past weather is like looking back at the stock market and expecting to predict the future. You can't say that climate change is here and then look back in the past when climate change was sorta here and expect to discover some repeat patterns. I have come to learn that the weather is what is over my head not what stats/predictors say it is. My collected rainfall amount has NEVER matched the "precipitation amounts recorded" once this year.


Well of course not. Why would you expect yours to match what someone else got in a different location?
I like the chart of reservoirs, good job. You have space for Lake Casitas in Ventura County, CA, but it is not listed. This lake is a significant water source in Ventura county.

Thanks
I think the blob really took shape this year , and forecasts of heavy rain have been starting to back off for this winter .Looking at long range its not looking much better
On December 24, Burlington Vermont broke their daily record high of 51 by 17 degrees, reaching 68. Their period of record begins in 1883. I've never heard of a station with such a long POR breaking a daily record by 17 degrees. Has that ever happened before?

Incidentally the 68 degree reading is the warmest ever recorded in Burlington between November 29 and March 14th.
One week to go!
http://www.stormsurfing.com/cgi/display_glob_alt.cg i?a=glob_250_alt
Pattern shift is taking over the Pacific in the coming week....
Thank you for this comprehensive report. As a non-resident this content was extremely educational.
You can write a Ñ por ñ justo type

ALT+164 = ñ
ALT+165 = Ñ
Chris... There is some potential for confusion. Your El-Nino chart is not for the winter season (DJF), it's for the 3 month NDJ period, and this January is not finished yet. In these 3 month ONI comparisons it is important to keep the contiguous YEARS in mind. 1997 and 1998 are quite different annually and seasonally.

The 2015 winter was last December thru last February, when the 2015 ONI was 0.5°C while 1997 was minus 0.5°C and 1998 was 2.1°C. On a calendar year basis, 2015 and 1997 tied at 2.3°C. But, on a seasonal year basis (WSSF)...1997 was "warmer". 1998 is very different...Calendar year 0.0, Seasonal year 0.3°C.
No "confusion" here. The chart is showing the beginning of the 2015-2016 El Nino season. This season is and will remain in the category of a strong/very strong El Nino event.


Quoting 25. Jawja:

Chris... There is some potential for confusion. Your El-Nino chart is not for the winter season (DJF), it's for the 3 month NDJ period, and this January is not finished yet. In these 3 month ONI comparisons it is important to keep the contiguous YEARS in mind. 1997 and 1998 are quite different annually and seasonally.

The 2015 winter was last December thru last February, when the 2015 ONI was 0.5°C while 1997 was minus 0.5°C and 1998 was 2.1°C. On a calendar year basis, 2015 and 1997 tied at 2.3°C. But, on a seasonal year basis (WSSF)...1997 was "warmer". 1998 is very different...Calendar year 0.0, Seasonal year 0.3°C.
weatherhistorian has created a new entry.