In some ways, the improving trend was expected. This is a very strong El Nino year and such years often bring heavy precipitation to California, particularly after January 1.
Let me start by showing you the forecast total precipitation for the next two weeks from the National Weather Service GFS model. Much of California gets 5-10 inches. As Darth Vader would say: impressive, most impressive.
The UW WRF model, which generally is superior to the GFS over terrain shows 2-5 inches over northern CA during the next 72 hr alone.
Looking long term, the NOAA CFS seasonal model is going for a very wet January through March over California. Classic El Nino pattern
The good news is that all this precipitation will fall on a state in which the situation has already started to improve. The latest snowpack measurements show the Sierra Nevada snowpack is well above normal.
And the GRACE satellite soil moisture measurements show most of California wetter than normal, with the exception of the far SE side of the State.
But with all the good news, one must consider that California's reservoirs are quite low as a result of a multi-year drought--roughly 50% of normal, as shown by this summary of the major reservoirs below. California has a very large number of reservoir and immense storage capacity. During the next few months, substantial rains should greatly increase the reservoir storage. I suspect this will be the turn around winter for CA and the end of the several year drought. But it may take several years to fully recover.
The approaching period of heavy rains has emergency management folks worried about California flooding and landslides. The LA Times has a big story on this:
Finally, it should be stressed that the large scale circulation patterns over the western U.S. are radically different this year than last. For example, we have not seen much evidence of the persistent West Coast ridge of the last few years and the BLOB is gone. There is no reason to expect a repeat of last year.
Our water deficit in California is immense. The talk around here is that it would take two very strong El Nino winters to completely erase the deficit. Due to almost no regulation, our groundwater supplies have been severely depleted over the last four years. Infrastructure is beginning to crumble because of the resulting ground deformation. And because most of the year is dry, it's not enough to simply have our reservoirs filled during the winter. A big snowpack in the Sierras is crucial for keeping the reservoirs full during the dry months. Glad to have some hope on the horizon though.
ReplyDeleteCliff,
ReplyDeleteI guess you're right about the lakes in California filling back up, but that's like saying things are great because the bathtub's full, ignoring that the tap is connected to a pipe connected to a water source that's only got a few gallons left in it!
It seems that only the deepest wells will be back on line quickly. The aquifers take decades to refill and may not do so, ever, after the massive drought and overuse of the limited water. Apparently the deepest layers of the aquifer can collapse in on themselves, permanently reducing the aquifer's water-holding capacity.
Here's a great analysis on how the land has sunk 36" in some places -- three FEET of subsidence -- because of emptying aquifers.
http://www.water.ca.gov/groundwater/docs/NASA_REPORT.pdf This includes data through January of 2015.
Three weeks ago, the Water Department released its 2016 Drought Contingency Plan. It will be updated January 15th.
http://www.water.ca.gov/waterconditions/
There are still 1655 households in California with NO WATER in the pipes (as of 12/10/15)!
https://mydrywatersupply.water.ca.gov/report/publicpage
I want to share your optimism, but I think it's pretty naive, and I'm surprised that you equate a lake with half the average water level as "drought over". It seems like we can reasonably call this "the beginning of the easing of the extreme drought" and we can all hope that California gets feet and feet more snow and rain (slowly and steadily, if they can get it that way).
I'm really glad you're reporting on this but I hope you will apply your knowledge and "climate-viewer" to the information, not just the "72-hour or "3-month weather viewer". In fifty years, the 3-month view won't matter, but the annual view just might.
Thanks
People have mentioned the aquifers in California. The news is worse then anyone here has suspected: they will never recover. Reason is tied to the subsidence at the surface. The subsidence has happened because as the water has been pumped out the formations that held it have collapsed. They won't un-collapse when they get saturated again (gravity will prevent that). The aquifers have been permenently damaged by California's failure to regulate groundwater use and will never again hold as much water as they once did.
ReplyDeleteI don't see a change in any but the short-term surface-reservoir drought situation. Even a single or two over average precipitation year doesn't make a noticeable change in the groundwater reservoir. After decades of below-average, it will take decades of over-average to correct the situation. The groundwater drought situation isn't changed at all by one good year. This takes many decades. Declaring that the drought is now over is highly misleading.
ReplyDeleteThis is the point where scientists, and the media, need to work together. As I understand it, there are two opposing future views of California:
ReplyDeleteApproach #1) Rains will return, reservoirs will refill, aquifers will recharge, and we go back to the way things were before, more or less. Until the next period of drought. The concept being that wet and dry periods are normal and will continue to occur. People just have to endure the bad periods by investing in better ways to store and use water, etc.
Approach #2) The drought has damaged aquifers which will never be useful as they once were, and that the future of a warming planet holds more periods of drought than periods of wetness. The state must make massive fundamental changes in how it uses water, and the sooner the better. A wet winter or two might buy a little time, but the eventual outcome is still the same.
These opposing viewpoints (which I'm sure others could state more succinctly) drive very different behavior at every level, from public policy, agriculture and individual consumption and preparation. Unfortunately, politics will try to twist this in red and blue ways, with both sides having immense amounts of short-term money at stake.
The problem is that this isn't a political problem. As the intrepid Mark Watney said in The Martian (and I paraphrase): "We're going to have to science the shit out of this thing."
Your Los Angeles Times headline says nothing about Emergency Management or flooding or landslides. I'm not sure why you included it. A quote from the emergency management people would gave been better.
ReplyDeleteI too am glad to see you reporting on our neighbors. The news can be somewhat biased and excited and your blogs are calmer and more factual.
A friend in California posted a picture on Twitter today of the ominous clouds, because they frighten him. Flash flooding is a real risk. Aquifers = good, flash floods = terrifying. :(
ReplyDeleteAnd this is why many move from California to Washington. We don't have crazy droughts and water shortages. And more people than water necessary to those people.
ReplyDeleteRain is better than no rain, eh?
ReplyDeleteI would think the California aquifer was formed by a similar process as the Ogallala Aquifer on the U.S. high plains. The Ogallala Aquifer was charged thousands of years ago during the glacial expanse and retreat. Geologists write, it will take many thousands of years for the Ogallala Aquifer to recharge naturally.
ReplyDeleteAs I understand it, aquifers are reservoirs and unlike ground water recharge slowly over long periods of time. Pumping water from an aquifer is mining a resource.
For now, I don't think California has much choice other than to balance it's water consumption with conventional rain/snow fall. The aquifers are a non-renewable resource. So hurray El Nino rains and snows! May you last through March.
This el Niño is a bit of relief in the ongoing California drought which could last 25 or 40 more years based on past climate data. However, if major El Niños occur with greater frequency all bets are off.
ReplyDelete"I would think the California aquifer was formed by a similar process as the Ogallala Aquifer on the U.S. high plains."
ReplyDeleteCalifornia's Central Valley (the location of the damaged aquifers), unlike the Great Plains, was not subject to glaciation in the recent ice ages. I find it doubtful that the processes of aquifer formation would be very similar in both cases.
I hope California does receive ample precipitation just like we have in Washington, more actually than here. But the part about NOAA....they are so unreliable anymore. It says chance of above precipitation in California and up here, but looking at the long range forecasts says below normal to maybe average up here. NOAA has also completely called the winter 100% wrong for the first part (I consider winter here in Eastern Washington from the middle of November, into late February, and then spring). Three months in a row, no deviation from the expected forecast. Nov: Above average temps, below precip=wrong. Dec: Above average temps, below precip=way wrong. Jan: Above average temps, below precip=verdict still out. The temps are probably going to move above average for the first time in a few months and stay there a bit, but I have a suspicion we still get at least normal precip for Jan, but it could be below, no clue now. More precip is very good for the water situation, though some of us in Eastern Washington are getting tired of storm after storm.
ReplyDeleteToday is Seattle's average minimum temperature day. It's all up from here!
ReplyDelete