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California: What a Difference a Month Makes

By: Christopher C. Burt, 9:58 PM GMT on January 08, 2016

California: What a Difference a Month Makes

One month ago I posted a blog about the precipitation deficits that were endemic in California at that time (December 9, 2015) but just prior to the beginning of a series of storms that rolled in. As was expected, the storm door opened and remains open. Here is where California now stands as of January 9th, 2016 precipitation-wise. Looking a lot better!

Precipitation Totals

Although there have been no major storms so far this season there has been a non-stop series of moderate storms affecting one portion of the state or other every few days since last December 10th. The northern and central portions of California were the main beneficiaries of these until this past week when southern California finally got into the act. Even more crucially, the Sierra has been plastered with heavy snowfall and, for the first time in several years, the water content of the snowpack is above normal for the season-to-date at this time (at least on an averaged state-wide basis). Below are some tables and graphics illustrating this.





The top table shows the rainy season-to-date precipitation amounts as they stood last December 9th and below that a table of where they stand now (as of January 7th) for selected sites across California arranged geographically from north to south. As one can see there has been a tremendous improvement at the central and northern sites whereas Los Angeles and San Diego are holding their own.

The final precipitation totals for the calendar year of 2015 (below) show how dry it has been in spite of the December rainfall. The entire state averaged well below normal and actually near-record dry for some locations, such as San Francisco which experienced its 4th driest calendar year on record since records began in 1849 with a 9.91” total (downtown). Its driest calendar year was just two years ago, 2013, when only 5.59” was measured.



Reservoirs and Snowpack Conditions

The runoff from the December rainfall has begun to finally replenish the state’s reservoirs. It will take a long time (probably not this year) to finally reach 100% of average. Below are a comparison of major reservoir levels as of December 8th and the situation now (January 7th). Note that the state’s largest two reservoirs (Shasta and Lake Oroville) have improved their percentage of historical average (for date) by 3% and 5% respectively. Folsom Lake has seen a huge improvement from 29% of normal capacity on December 8th to 53% now.





California state reservoir capacity levels as of December 8, 2015 (top) and January 8, 2016 (bottom). Apologies for the change in the map designs, it appears the CA Dept. of Water Resources has made a design change sometime this past month. Maps provided by the California Department of Water Resources.

Similar to the maps of the reservoirs are the maps comparing the snowpack water content as of December 8, 2015 and now (January 7). Overall, the percent of normal to date went from 59% on December 8th to 107% currently.





Snowpack water equivalents as percentage of normal as of December 8, 2015 (top map) and as of January 7, 2016 (bottom map). Again, the design of the maps has changed slightly over the past month. Maps provided by the California Department of Water Resources.

Here is how the snowpack water content this season (so far) compares with last season as well as comparisons to the driest and wettest seasons on record:



The purple line is where we stand now for each of the Sierra regions (north, central, and south). Last season (2014-2015) ended up tied or a little drier than the previous driest season on record of 1976-1977. Graph provided by California Department of Water Resources.

The hope, at this point, is that the storms will continue to roll in on a regular basis for the rest of the winter and spring. With the El Nino still on track to be one of the strongest if not the strongest on record, there is a good chance this will happen despite a few dry spells from time to time.

Christopher C. Burt
Weather Historian

Extreme Weather Drought

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

Thanks for the Great post!!
I live in central California across the Golden Gate Bridge from San Francisco and we have been enjoying the cooler than average rainy season so far! Lots of snow in the mountains. Let's hope the storm door stays open for a long, cold and wet winter for the entire west coast!

Cheers!
-Patrick
Encouraging progress, though thanks to a powerful El Nino. Looking ahead to the rainy season of 2016-2017 and those beyond, California may not be blessed with such an El Nino and its restorative power. The fundamentals of the sheer size of its population and the water demands of its agriculture remain. One good year could tempt some policy makers to back off needed, but potentially politically and economically unpopular, sustainable long term measures. It will be an interesting test of their resolve.
Glad to see that California is getting relief. I hope it does continue, but they cannot let their guard down.
This California dew is just a little heavier than usual tonight :)

California drought: How will we know when it's over? - San Jose Mercury News
(For the full article click the link above. Below is an excerpt.)


Now that 2016 has gotten off to a wet start, with a series of El Niño storms drenching California in recent days, the question is turning up with increasing frequency at dinner parties and coffee shops:

"How will we know when the drought is over?"

The answer, water experts say, is more complicated than you'd think.

Simply put: The drought could end this year, according to state water officials. But for that to happen, as California enters the fifth year of the worst drought in the state's history, rains will have to continue arriving in pounding, relentless waves through April to fill depleted reservoirs and dry rivers and push the Sierra snowpack to at least 150 percent of normal

"One week of rain doesn't make up for four years of historic drought. We are in a very deep hole," said Mike Anderson, California's state climatologist.

Other disasters are easier to understand. Everyone knows when a forest fire is contained, an earthquake stops shaking or a tornado has passed.

But with California droughts, there isn't widespread agreement among scientists and water managers about what signifies the finish line. California is a huge state, with many different climates, water sources and water users. Decent rain over a few months may be enough to grow green grass so that a Sacramento Valley cattle rancher's business returns to normal in one season. But it might not fill reservoirs enough so a Bay Area city can lift water conservation rules.

"As they say, all politics is local. And all droughts are local," said Jeanine Jones, a top drought manager at the state Department of Water Resources. "The impacts are in the eye of the beholder."

Many experts say that if the state's big reservoirs fill, the drought will be over because it will be nearly impossible to convince Californians there is a drought emergency when they see water rushing over spillways and headed out to sea.

Others say California needs to make up the sizable rainfall deficit over the past four years, which almost certainly won't happen this winter. Other experts say that California has to replace billions of gallons of overpumped groundwater to have a true recovery -- which will take decades.

"How will we know when the drought is over?" said Leon Szeptycki, a water use attorney and executive director of Stanford's Water in the West program. "That's a really good question. There are lots of different answers."

....(snip)
Great article LowerCal. Thanks for posting.
The one factor that never seems to arise in all these pretty graphs and pictures is relative population increase of the same periods of time. A reservoir that was "full" for 100k people is highly lacking for 120k people. Without an increased population use of the commodity, these comparatives are misleading other than as a looking backwards thinking. Needed moisture vs current levels should be the concern of all.
So many issues have arisen from over pumping of groundwater and we do not see direct response to replenish deep water sources. Surface water reservoirs are only part of the issue. I do not have an answer but I see a much longer term problem that appears to be ignored.
You deal with increased population with conservation, and/or building more reservoirs. Cannot rely on Mother Nature to deal with increased population. Love the charts and data to get a sense of where we stand in regards to the drought.
Quoting 8. Hunter401:

You deal with increased population with conservation, and/or building more reservoirs. Cannot rely on Mother Nature to deal with increased population. Love the charts and data to get a sense of where we stand in regards to the drought.


Building more reservoirs isn't going to do anything if Mother Nature doesn't provide the water. CA has been draining water from a massive area faster than nature can replenish. The aquifer is compacting on itself in parts of Central Valley. Desalination is probably going to be serving a larger and larger role.
Very nicely done article. Informative and easy to understand. I look forward to updates as the new year goes on.
Sure wish we'd get more rain in SoCal. While it has been cloudy and cool, the storms are just not holding together enough to have much in the way of rain by the time they get to us. I realize SoCal rainfall has little effect on the total state's drought, but it would be nice to get more use out of my umbrella.
This may also be of interest:

California farmers brace for water shortage despite El Niño | 89.3 KPCC
(For the full article click the link above. Below are excerpts.)
Farmers in California's fertile San Joaquin Valley are bracing to receive no irrigation water from a federal system of reservoirs and canals for a third consecutive year and looking to El Niño to produce the very wet winter they need.

....(snip)

While many are celebrating a break to the long dry spell, however, the four driest years on record for California have left their mark, and experts say it will take time for the parched state to recover.

"We need a wet winter this winter and next and the following winter probably to get us anywhere close to equilibrium," said Dave Kranz, a spokesman for the California Farm Bureau Federation.

State water managers say California's snowpack needs to be at 150 percent of normal on April 1 to signal an end to drought. Friday it was at 110 percent, according to the Department of Water Resources' statewide electronic reading.

Lake Shasta, the state's largest reservoir, remains at half of its historical average for this time of year. Other major reservoirs in Oroville and Folsom that collect and store rain and snowmelt had reached or came close to historical low levels before the winter storms hit.

....(snip)

Westlands Water District, which relies on water from the U.S. Bureau of Reclamation, has warned hundreds of farms it serves in the San Joaquin Valley that they may not be receiving any irrigation water yet again this year, said district spokeswoman Gayle Holman.

....(snip)

The Water Resources Department, which also manages part of California's vast water system, said in early December that it anticipated releasing 10 percent of expected supplies this year — half of the last year's allocation.

....(snip)
Chris, I have your book "Revised and Updated Extreme Weather: Climate Change Edition". While this is a fascinating read I suspect that it might be a bit dated now. You will likely need to make plans for annual updated editions when we consider the rate of change that the climate is going through now. Perhaps you should offer an annual subscription service?
Great graphics! Thanks. We can only hope that here in California we will continue getting periodic rain until the summer and greater snowpack in the Sierra Nevada. The drought can't last forever!
Funny you mentioned that! I've been thinking of publishing a print-on-demand annual almanac of extreme weather events (for each given year) with updates to all of the records for the sites I follow in the U.S. (and around the world). Any takers out there?

Quoting 13. Some1Has2BtheRookie:

Chris, I have your book "Revised and Updated Extreme Weather: Climate Change Edition". While this is a fascinating read I suspect that it might be a bit dated now. You will likely need to make plans for annual updated editions when we consider the rate of change that the climate is going through now. Perhaps you should offer an annual subscription service?
Here's hoping for the best, but when I crossed Lake Shasta on 1/9/16 it still looked like a river in a canyon. And as I drove further south toward Bakersfield I couldn't dismiss the irony of farmers and ranchers decrying their lack of water while still planting thousands of acres of new trees and vines. If they don't have enough water for what's already in the ground, how in God's name are they going to irrigate these new fields in what is, essentially, a desert.
Quoting 15. weatherhistorian:

Funny you mentioned that! I've been thinking of publishing a print-on-demand annual almanac of extreme weather events (for each given year) with updates to all of the records for the sites I follow in the U.S. (and around the world). Any takers out there?
I would :)
Quoting 18. BaltimoreBrian:

California Residences Threatened as Cliffs Crumble (with video)


In France, to the northwest of Bordeaux in Soular s/Mer, there are similar problems, during winter storm time. A large building, with some dozens of appartments was already evaquated some years ago.
Coastal erosion on the Atlantic coast in France
Quoting 19. ChateauChalon:



In France, to the northwest of Bordeaux in Soular s/Mer, there are similar problems, during winter storm time. A large building, with some dozens of appartments was already evaquated some years ago.
Coastal erosion on the Atlantic coast in France


I could not get your link to work. Is this it?
Quoting 20. Some1Has2BtheRookie:



I could not get your link to work. Is this it?


Yes, thank you!
Quoting 7. SusanCooper:
The one factor that never seems to arise in all these pretty graphs and pictures is relative population increase of the same periods of time. A reservoir that was "full" for 100k people is highly lacking for 120k people. Without an increased population use of the commodity, these comparatives are misleading other than as a looking backwards thinking. Needed moisture vs current levels should be the concern of all.
So many issues have arisen from over pumping of groundwater and we do not see direct response to replenish deep water sources. Surface water reservoirs are only part of the issue. I do not have an answer but I see a much longer term problem that appears to be ignored.
I agree that population growth should be factored in when considering things like "historic level for this date" statistics, but I suspect it is a nontrivial exercise. One should also consider changes in per capita water use at the same time. I wonder what graphs of that look like. But the major water user in California is agriculture, so the data should be related to agricultural trends first. Mr. Burt has his work cut out for him!

Water mining has been discussed on this blog before (Astrometeor references it back at comment 9 for example), but we can't help the problem. Yes, I think the people of California are mostly ignoring the problem. At the same time, I'm not sure what even they can do about it, not without some major adjustments in how they go about daily business.
I live in Calexico area, we have more expectation for the announcement about rainy days because of “El Niño”, but this was not dramatically as predicted, just a few minutes of intense rain occasionally, but a lot of water and wind. This is good; we can sort the precipitation deficits this way. Just having a little inconvenient, because the water capitation systems need more support against the wind. But are good news finally. Great Web Site you have, and the graphics make it more friendly.
Dude…what a difference another month makes. Its the middle of Feb. and we've been near 90 deg. for the whole month. Where was that in your crystal ball ? Its strange that meteorologists are great at telling us what just happened, but not what's going to happen. All that schooling just to be able to collect some published data and make a chart. Well done. Hope you can pay back your student loan.
Thank you so much. With the eco-greenies and there environmental agenda of control and constant crisis. It is really nice to see some facts and figures about the rain totals. I have noticed that the usual sources such as TV news, newspapers and radio don't seem to find the time for the rain totals. Why I can't understand, perhaps it is the idea of "never waist a crisis". Most people are concerned about the drought and want to know. Once again thanks for the information.
Rosinante
What's it look like at the end of February 2016 would be nice to see, so in a few days get busy!
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