February 02, 2016

California Reservoirs Filling Rapidly After Heavy Precipitation

If you enjoy vegetables, fruit, and wine from California at a reasonable price, this has been a good week for you.  Heavy rain has been hitting the mountains of northern CA and the Sierra, with many reservoirs filling rapidly.    Let me show you.

Here is the  precipitation over the past 7 days over the southwest U.S.  Some locations in the northern Sierra range have gotten over 6 inches of liquid water, as have the coastal mountains over the northwest corner of the state.  Not too much to cause flooding, but enough to provide large volumes of water.

California has a LOT of reservoirs with a huge, multi-year, storage capacity.   A nice summary of some of the major reservoirs are shown below.

The three biggest reservoirs are Lake Shasta, Lake Oroville, and Millerton Lake;  Folsom Lake is near the precipitation maximum.   Looking at the big Kahuna first, Lake Shasta, one sees a precipitous and huge increase in water storage (the blue color shows average levels for various times of the year).   Impressive.

The second largest reservoir shows a similar, but more modest, large increase.
But if you really want to be impressed, take a look at Folsom Lake--now above normal!

And even with the substantial atmospheric river activity, the California snowpack has been maintained at above-average levels.

California is going to have be content with their watery bounty for a while, since the circulation is shifting with more ridging along the West Coast and rainfall moving back towards the Northwest.   To illustrate, here is the 10-day total precipitation from the NWS GFS model. Plenty in our mountains and enough to keep northern CA moist, but nothing over the southern half of the state.

It will be cold enough for lots of snow in our mountains.  The Northwest drought is over and I suspect the same will be said for California in a few months.


  1. What about all the water we pulled out of the ground? Is the drought over until the water tables go back up?

  2. Is it supposed to warm up in the mountains here in pnw? Looks like it will end up being rain below 4,000 feet?

  3. There have been highway closures due to slides in Humboldt, Del Norte, and Trinity counties. Those 3 counties are in the red section. Rivers were reaching flood stage, but not going over. Lots of flooded and closed roads, especially in Humboldt.

    So while the rain is nice for the rest of the state, it sucks in that area.

  4. It is possible SoCal doesn't get the massive rains that were forecasted. Though I have read some sources stating that SoCal can get slammed with rain in March, on El Nino years. It happens or it doesn't happen. The weather will do what it wants regardless of El Nino or La Nino, or whatever.

    Either way, as Sunsnow21 questions, why have the forecasts in this area been wrong about precipitation? A SoCal meteorologist I watch on Youtube stated that for some reason a massive area of high pressure is constantly weakening storms coming in off the Pacific, and/or pushing them north. On the one hand, I do appreciate that this year should be much more normal for water in the PACNW. Again, Snoqualmie Pass is way above normal still....for this time of year, having received 306 inches so far. This ironically is 13 inches above the weak winter of 13-14 and 3 TIMES above last years abnormally dry winter. And yes I mention Snoqualmie because you have 3 huge reservoirs in this general area which have all gotten high precipitation: Kachess, Keechelus and Lake Cle Elum. A big storm coming through tonight will dump a bunch more up high....not sure about Western Washington lowlands, a little in Eastern Washington lowlands though. And while I am absolutely ready for the ground cover snow to all melt away, I personally think this "failure" of forecasts has been a blessing for the water situation. I know a lot of relieved farmers in this area, as the water situation will be much better over last year.

  5. As soon as I read this post's headline, I thought to myself, "Oh no, Cliff's going to say the California drought's almost over again." And there it was, in your final sentence. The water experts in California VEHEMENTLY disagree with you. On Tuesday, the passed an extension of the Water Emergency until October 2016, which can only possibly be lifted after an April 1 assessment of the snowpack. http://www.swrcb.ca.gov/press_room/press_releases/2016/pr2316_reg_extension.pdf

    Saying the drought is over is like a family deciding to go to Disneyland when they get a $5000 check even though they have a $20,000 credit card balance. It's not good budgeting and it will lead to disaster.

    It's great that the state is getting rain and snow, don't get me wrong. It will slake the most dire, immediate need. But it's still not enough to recharge the huge deficit of aquifer water, and only time and lots more water can do that if the aquifer has not collapsed (as it has in some parts of the state).

    I love your optimism, but it is leading you to make inaccurate statements that make me question the accuracy of all the conclusions you draw before the "end of the drought is near".

  6. Jewelyaz,
    California has been mining its subsurface waters. It has been doing this for quite a while. Some of this is ancient water. These acquifers will not be restored even with normal precipitation. So if your definition of drought demands the restoration of the acquifer, we will NEVER be out of drought. I don't think this is a reasonable definition. I would suggest drought deal with seasonal precipitation, snowpack, reservoir level, and surface and near near surface water content. By that definition CA has a good chance of getting out of drought. ..cliff

  7. This El Nino has been GREAT for the PNW. Ample rain has fallen in the lowland and good mountain snow.

    Our only source of fresh water on Vashon Island is ground water so the soaking rains are great!

    I've recorded 35.51 inches of rain since Oct 1, 2015. For February, as of the 4th, I've recorded 1.03 inches with more on the way. The Hellebore are blooming and the daffodils are up. Catkins on the Corylus.

    This year, it hasn't snowed enough to make a slush ball let alone a snowman. Back in the 80s and 90s when our kids were small, we made snowmen and had snowball fights almost every winter. Those days are gone. Haven't seen a really good snow on Vashon this century.

  8. Cliff, if the water managers and hydrologists of the state think it's necessary to extend a drought emergency through October through legislation, it doesn't seem that it's over yet. Maybe when they get to April 1 they will be able to lift some restrictions, and that would be fantastic. Seems too soon to call it though, since even with the exceptionally strong El Nino there's been a persistent blocking high that's kept southern California much drier than it would normally be in this scenario. It will be interesting to see how the next two months play out, for sure.

  9. Anyone who honestly looks at CA's water history going back a couple hundred years knows that the drought was par for the course. Now it's snapping back. The real issue there is a lack of adequate reservoir capacity. For some reason that I can't understand, the "environmentalists" have opposed building reservoirs.

  10. Lots of comments pointed out how reservoir replenishment is a stopgap solution for a long term problem. It's great that they are going to have extra water, but California has a long term huge water mismanagement history, and the constant depletion of ground water is the result - a fat reservoir is not going to fix that. Unfortunately, the short term fix might allow the State to kick the can down the road once more (even though I read that the water authorities are aware of the difference between short term and long term), keeping the ridiculous water allocation rules, as well as the outrageous waste in water consumption in agriculture (ridiculous - waterwise - crops, like almonds), in golf courses, general extra lawns, or swimming pools.

    Like many already said, it's almost irresponsible to predict that "California's drought will soon be over". Cliff, I am old enough not to really be affected (and I also live in Washington), but short term fixes do not solve long term problems, and you should know better.

  11. The definition of drought meteorologically is based on a regions average rain not their use. Mismanagement and average rain are mutually exclusive.

    Words like "suspect" and time frames like "few months" indicate uncertainty and are based on predictions which are just that, predictions, not truth. You are here for predictions not fortune telling. You are getting information about weather, not water management. Get a grip people.

  12. The internet sure is a weird place. I don't know many other places where random strangers would lecture a PH.D in atmospheric sciences on the very topic he's spent his entire adult life studying. Cliff, I don't know how you put up with these jokers.

  13. The internet is also a place where information is at your fingertips, and it is okay to challenge somebodies statements, if you have legit proof. I personally come here to learn something, and to see what others are saying. But if something doesn't seem right I will post my rebuttal, with proof. For example, here is a recent article about California. http://www.capradio.org/articles/2016/02/11/california-drought-improvement-will-take-quite-a-while/

    Not looking so good right now, and with rising temps.....who knows what the winter will ultimately say about precipitation in California.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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