More of the “extreme events” meme…
From the AGU weekly highlights
Regional models expect drier, stormier western United States
Key Points
- Statistically significant increases in western US future extreme winter precipitation
- Eight dynamically downscaled GCM simulations show generalized agreement
- Spatial pattern of changes in mean precip. is different than that of extremes
As American southwestern states struggle against ongoing drought, and the Northwest braces for a projected shift from a snow- to a rain-dominated hydrological system, climate researchers strive to provide precipitation projections that are fine grained enough to be of value to municipal water managers. Estimates derived from large general circulation models show that in a warming world, water availability in the western United States will be increasingly dictated by extreme events.
However, such large models tend to lack necessary detail for the small-scale interactions and topographic influences that dominate daily changes in local precipitation. To convert the broad predictions of global models into practical predictions, Dominguez et al. used an ensemble of regional models, set to fit within the projections of general circulation models, to estimate future winter average and extreme precipitation for the western United States.
The authors find that for the years 2038–2070, winter average precipitation in the southwestern states would be 7.5 percent below 1979–1999 levels. They also find, for the entire areal-averaged western United States, a 12.6 percent increase in the magnitude of 20-year-return-period winter storms and a 14.4 percent increase for 50-year winter storms. In some regions, like southern California and northwestern Arizona, this increase in strength of 50-year storms was pushed as high as 50 percent. Though the temporal and spatial granularity of the regional climate models is much improved over that of general circulation models, workable and useful measurements for hydrological engineering and water management design will need ever-better estimates of future rainfall patterns.
Source:
Geophysical Research Letters, doi:10.1029/2011GL0507624, 2012
Title:
“Changes in winter precipitation extremes for the western United States under a warmer climate as simulated by regional climate models ”
Authors:
- F. Dominguez, E. Rivera, and C. L. Castro
- Department of Atmospheric Sciences, University of Arizona, Tucson, Arizona, USA;
- D. P. Lettenmaier
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington, USA.
Abstract:
We find a consistent and statistically significant increase in the intensity of future extreme winter precipitation events over the western United States, as simulated by an ensemble of regional climate models (RCMs) driven by IPCC AR4 global climate models (GCMs). All eight simulations analyzed in this work consistently show an increase in the intensity of extreme winter precipitation with the multi-model mean projecting an area-averaged 12.6% increase in 20-year return period and 14.4% increase in 50-year return period daily precipitation. In contrast with extreme precipitation, the multi-model ensemble shows a decrease in mean winter precipitation of approximately 7.5% in the southwestern US, while the interior west shows less statistically robust increases.
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RockyRoad says:
March 30, 2012 at 7:58 am
So regardless of the outcome, they can take credit for it. Pretty shifty devils, if you ask me.
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It is called politics: http://www.youtube.com/watch?v=NJG75FJkjr8&feature=youtube_gdata_player
Models … Right and I believe the models why?
No really weather prediction is doing great if it is accurate to 5 – 10 days out. I’ve watched the predictions and results shift just 24 – 48 hours out as a weather system doesn’t act as predicted. Either speeding up or slowing down or even going some other direction. And I’m supposed to believe that computers models can accurately predict what the weather {because storm patterns are weather,} will be doing 26 – 68 years in the future?
Really?
You got to be kidding me.
We get most of our moisture here from “extreme events” now, so what’s the big deal. I guess it’s gonna get extremer. Really impressive how these models that have so far predicted nothing correctly, even on a gross scale, can make such specific, detailed, predictions.
THE BOY WHO CRIED WOLF
… “There really was a wolf here! The flock has scattered! I cried out, “Wolf!” Why didn’t you come?” An old man tried to comfort the boy as they walked back to the village.
“We’ll help you look for the lost sheep in the morning,” he said, putting his arm around the youth, “Nobody believes a liar…even when he is telling the truth!”
Climate model predictions on regional scales are even wronger than their global predictions. Even global warming scientist stand-ins acknowledge that. What do Dominguez, Rivera, Castro and Lettenmaier want to accomplish, set a new record in charlatanery? Test what they can get away with?
“To convert the broad predictions of global models into practical predictions, Dominguez et al. used an ensemble of regional models, set to fit within the projections of general circulation models”
1000 For K-1 to Fit
1010 If K=Fit go to 3000
Otherwise referred to as pretzel logic. You take the output of a GCM, of which we know none that have predictive skill, then use that to feed input to regional models (see Pielke, Sr.) which are “set to fit within the projection of GCMs”
2000 K=K+1
2010 Go to 1000
3000 Call sub: “Nice steaming bowl of…”
4000 END
Just for the record; NE and North Central Texas (think: DFW area) is out of ‘drought’ classification. Other parts of the state may not be so lucky, however. http://droughtmonitor.unl.edu/
Most of the US Corps of Engineers ‘lakes’ (reservoirs) upon which we depend for our drinking water in our area are at, or above, ‘conservation’ (normal) pool elevation fortunately:
http://www.swf-wc.usace.army.mil/reports/fish.htm
A couple reservoirs, like POSSUM KINGDOM west of Ft. Worth are a few feet low yet, on the order of 5 feet presently.
We are sitting in a pretty good position for the summer, especially considering we can add a few more feet to most of these reservoirs with expected rains the next couple of months before our ‘summer’ starts (June). Now our worry is electricity supply (if the summer turns out to be really hot)!
.
I have a friend who has told me of the extensive evidence of shifting precipitation due to global warming. So I decided to check it out. Haven’t done too much yet, but have looked at part of California and what I have found is decidedly not alarming. (Click on name above.)
Now it is possible that there could be future massive shifts and changes in precipitation over the next 68 years than we have seen in the past 90+, but it would take more belief in models than I can muster . . .
Aren’t there really only three possibilities ?
No change.
Wetter.
Drier.
They have a 33% chance in their prediction of being correct.
Sunshine…Lollipops… or Rainbows. Pick one.
These would be the same models that had Brisbane spend billions on desal plants just before the dams overflowed…
Funny that historically, SW US drought coincided with times of global cooling while global warmth brought wet conditions. In the desert, daytime surface temps during periods of low humidity are higher then periods of high humidity. Humidity DRIVES surface temperature. The temperature does not drive humidity. And as for all that non-sense about increased transpiration … desert plants do not behave anything like the temperate forest flora that the moonbat researchers use for their ill conceived models. The soil fungus’s alone jealously store huge amounts of water. One more thing, the desert gets half of its rain via violent weather events. Always has, always will.
BTW, perverting my homeland unique environment so that it can be used as propaganda is a particular peeve of mine.
“[…] climate researchers strive to provide precipitation projections that are fine grained enough to be of value to municipal water managers. […]”
Ask the Aussie water managers how the models worked out for them.
/jaundiced-eyed grumble
Craig Goodrich says:
March 30, 2012 at 9:03 am
These would be the same models that had Brisbane spend billions on desal plants just before the dams overflowed…
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But Craig, those models worked perfectly. Just consider the take home profit for the desal plant top dogs.
One more thing: Remember that “Record” SW drought the news kept yammering about a few years back? Seemed like every news show had to do a story on it for weeks. Well, it was not close to being a record, that was set during the early 70’s with 168 days of no rain!
So, they predict it’ll be drier except for those times when it’ll be wetter — and were (presumably) paid to produce said prediction.
I want a job like that…
I also have a problem with the “ensemble of models” concept.
If “model A” is the correct one, why bother to mix it up with other models that give different outcomes which are obviously wrong, since they are different from the correct one? If you mix a bottle of fine wine with 5 bottles of vinegar you will waste your bottle of fine wine.
And If none of the models are right. Why do they expect to obtain a correct answer by averaging a bunch of wrong models? No matter how many bottles of vinegar you can mix, you will never get fine wine out of the mix.
Drier and stormier…not good
Craig Goodrich says:
March 30, 2012 at 9:03 am
These would be the same models that had Brisbane spend billions on desal plants just before the dams overflowed…
==========
The dollars are cheap today and the desal plants will pay off down the road. In the best of times it makes sense to prepare for the worst of times but the logic doesn’t need to be based on lies about Global Warming and inferior tech solutions.
It turns out that its cheaper to use desal than it is to transport water around California. Building desal plants next to energy plants makes it even cheaper but Australia decided to use wind power for the desal energy source so your basically screwed.
Live and learn I guess…
[ Estimates derived from large general circulation models show that in a warming world, water availability in the western United States will be increasingly dictated by extreme events. ]
So build some more dams……..even the government could complete some by 2038.
Hey, let’s ask the Anasazi about climate change.
http://www.learner.org/interactives/collapse/chacocanyon.html
[These would be the same models that had Brisbane spend billions on desal plants just before the dams overflowed.]
The Army Corp of Engineers must have borrowed your models for the Missouri River flood of 2011.
Pamela Gray says:
March 30, 2012 at 6:56 am
“. . . and probably even bait casting.”
I saw what you did there!
If the researchers did more bait casting they might better understand the environment.
The three great lies:
(1) Yes, I’ll respect you in the morning.
(2) Vote for me and I’ll ….
(3) The models say …
Tim Clark says:
March 30, 2012 at 9:37 am
[These would be the same models that had Brisbane spend billions on desal plants just before the dams overflowed.]
The Army Corp of Engineers must have borrowed your models for the Missouri River flood of 2011.
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Don’t blame the Army Corp of Engineers. Blame the Democrat who diverted funds to subsidize poverty that should have gone to doing what the Army Corp of Engineers had been saying needed to be done for FORTY years!
Eventually, the forecasts are going to reduce to “the climate is going to get wetter and drier in a warming world”.