Major Snows Not due to AGW

[tacoman25]

Well then I would have to disagree with Rusty.. as there is no observational basis (yet) to say precip has increased. Our observation network is pretty inadequate though especially over the places that the change is supposed to occur (arctic) so this doesn't concern me very much. The global change is also projected to be fairly small, given the sub-tropical drying.

The fact that global precip is higher during Ninas years doesn't not negate the idea that global precip will be higher in a warmer world. Climate models accurately simulate heavier precip during Ninas, but they also project an underlying long term increase. I think the mechanism for this is pretty apparent. There is an underlying upwards trend in water vapor due to the Clausian Clapeyron equation and warming SSTs. During Ninas the global temperature falls and you experience a temporary spike in precip.

Wow...this sounds familiar, doesn't it? Except you believe the temperature observation network is just fine, including the Arctic.

Well, if we have no observable evidence of increasing water vapor (5-6% should be significant) leading to more precip, that idea of a direct relationship has no support at this point.

[skierinvermont]

Wow...this sounds familiar, doesn't it? Except you believe the temperature observation network is just fine, including the Arctic.

Well, if we have no observable evidence of increasing water vapor (5-6% should be significant) leading to more precip, that idea of a direct relationship has no support at this point.

It's vastly inferior to the temperature observation network. Precipitation is also much more variable than temperature and therefore requires more data to find statistically significant trends. Instead of more data, we have less data.

With precip we detect a global trend of less than a mm/decade when precipitation at a given location can vary by 200+ mm from year to year. So the ratio of annual variability to the decadal trend is 200 to 1.

With temperature we detect a global trend of .2C/decade when temperature at a given location varies by only a couple C from year to year. The ratio of annual variability to the decadal trend is only 10:1.

So you can see how precip is much more variable and the former trend would not be significant while the latter one is. It takes much more data to detect a 1 mm/decade trend in precip when annual precip can vary by 200+mm, than it does to detect a .2C/decade trend in temp when annual temp varies by about 2C.

You really have to be familiar with statistics to understand how much vastly more precip data you would need than temperature data to deduce trends.

[BethesdaWX]

If we cannot even accurately predict the Water Vapor/Global Precipitation realtionship, how can we accurately predict how Solar/IR, GCC, CO2, GCR, MagF decrease, Deep Ocean Currents, etc, impact the our atmosphere & then the global temp? Co2/Atmosphere/energy storage is alot more complicated than Water Vapor/Global precip.

Point being, we are just digging ourselves into a deeper hole...we should stop digging and chill out knowing there is nothing we can really do even if signficant AGW IS real

Bottom line...Global precip has not been doing what we planned it would, and tne notion that heavier snows/blizzards are due to AGW is crackpot science.

[tacoman25]

It's vastly inferior to the temperature observation network. Precipitation is also much more variable than temperature and therefore requires more data to find statistically significant trends. Instead of more data, we have less data.

Of course. If the data doesn't match the expected trend, it's a data problem.

Everything is going to plan, models have it figured out, no surprises.

If the data consistently shows matching trends with ENSO/PDO, I don't see any reason to believe it's faulty and is missing an increasing trend.

[WeatherRusty]

And that's why my initial question was, ok, so water vapor has supposedly gone up 5-6% over the past 100 years...shouldn't there be an observable increase in precipitation then?

And contrary to WeatherRusty's earlier assertion, the warmest years have NOT been the wettest years. The opposite is actually true, since La Ninas produce more global precip and El Ninos less.

I didn't say that . I said having a warmer year does not PRECLUDE the possibility of having a snowy year overall. We know this because it has just happened. Jezzzzzz!!

[skierinvermont]

Of course. If the data doesn't match the expected trend, it's a data problem.

Read my edit. If you have a fundamental disagreement with the conclusion that the precip data is vastly inferior at detecting trends than the temperature data, I would love to hear your argument. We have less data for precip, but detecting precip trends requires far more data than temp data because precip is far more variable compared to the underlying trends.

There is a fundamental reason that it appears as if data which doesn't match the conclusions is always deemed poor while data which does match expectations is deemed good. The fundamental reason is that climate model predictions are fairly accurate for large scale phenomenon. When we have good data we find that it matches expectations. When we have bad data, we find that it doesn't.

Just imagine a hypothetical world in which climate models actually are fairly accurate (must be hard for you) .. do you really expect that in this hypothetical world that every single piece of observational data would match expectations regardless of the quality of the data? No, of course not. Not all observational data is good. This is true in any field of science.

[BethesdaWX]

Read my edit. If you have a fundamental disagreement with the conclusion that the precip data is vastly inferior at detecting trends than the temperature data, I would love to hear your argument. We have less data for precip, but detecting precip trends requires far more data than temp data because precip is far more variable compared to the underlying trends.

There is a fundamental reason that it appears as if data which doesn't match the conclusions is always deemed poor while data which does match expectations is deemed good. The fundamental reason is that climate model predictions are fairly accurate for large scale phenomenon. When we have good data we find that it matches expectations. When we have bad data, we find that it doesn't.

Just imagine a hypothetical world in which climate models actually are fairly accurate (must be hard for you) .. do you really expect that in this hypothetical world that every single piece of observational data would match expectations regardless of the quality of the data? No, of course not. Not all observational data is good. This is true in any field of science.

Still, the areas that the Stations do cover should be following the "forecasted" trends...they are not.

If you stick to your argument, you need to say the same thing about GISS...because its the exact same thing, just temperature wise.......ok?

[tacoman25]

Maybe cause and effect can't be demonstrated factually, but these recent heavy snows have occurred during very warm years. So, heavy snow storm events are not precluded during warm years and likely are enhanced by the additional warmth and moisture availability. Would such be the case in a world 2C warmer than today?

More moisture availability? Why are some of the wettest years on record cold years then?

Or what exactly are you arguing? Why would a warmer year enhance the possibility of heavy snows?

[skierinvermont]

Trying to detect a 1mm/decade trend amongst data that varies by 200+mm year to year is like trying to find a needle in a haystack. The ratio of the trend to the variability is 200+ to 1.

This is just simply not comparable to the situation we have with temperatures that show far less variability relative to the magnitude of the underlying trend.

We find a trend of .2C/decade amongst data that varies by only a couple C year to year. The ratio of the trend to the variability is a mere 10:1.

The comparable situation with precipitation is if we were experiencing a 20mm/decade increase in global precip. Of course no change anywhere close to that magnitude is expected.

It would be like NYC's annual precip increased from 25" to 40" from 1900 to present.

[tacoman25]

It's vastly inferior to the temperature observation network. Precipitation is also much more variable than temperature and therefore requires more data to find statistically significant trends. Instead of more data, we have less data.

With precip we detect a global trend of less than a mm/decade when precipitation at a given location can vary by 200+ mm from year to year. So the ratio of annual variability to the decadal trend is 200 to 1.

With temperature we detect a global trend of .2C/decade when temperature at a given location varies by only a couple C from year to year. The ratio of annual variability to the decadal trend is only 10:1.

So you can see how precip is much more variable and the former trend would not be significant while the latter one is. It takes much more data to detect a 1 mm/decade trend in precip when annual precip can vary by 200+mm, than it does to detect a .2C/decade trend in temp when annual temp varies by about 2C.

You really have to be familiar with statistics to understand how much vastly more precip data you would need than temperature data to deduce trends.

Then why do we see clear, consistent trends with precip in regards to ENSO/PDO cycles? And why would longterm graphs even be produced if the data was inadequate to deduce accurate trends?

Most importantly, perhaps, why did you not start arguing about the "inadequacy" of the precip network until you discovered that the trend didn't match expectations?

[skierinvermont]

Still, the areas that the Stations do cover should be following the "forecasted" trends...they are not.

If you stick to your argument, you need to say the same thing about GISS...because its the exact same thing, just temperature wise.......ok?

NO it's not, as I've explained 3 times now Precip is far more variable than temperature relative to the expected magnitude of global trends. You need far more data to derive statistically significant trends. Instead, we have less data.

[skierinvermont]

Then why do we see clear, consistent trends with precip in regards to ENSO/PDO cycles?

Because they are much larger in magnitude than any expected underlying trend.

[tacoman25]

Because they are much larger in magnitude than any expected underlying trend.

See my edit.

[tacoman25]

Because they are much larger in magnitude than any expected underlying trend.

So you are now arguing there is no meaningful longterm change in precip expected?

[BethesdaWX]

NO it's not, as I've explained 3 times now Precip is far more variable than temperature relative to the expected magnitude of global trends. You need far more data to derive statistically significant trends.

huh? Absolutely not....provide me some reference. Warming of the oceans........at the magnitude we've seen..........should have produced a MAJOR rise in precipitation if it is indeed true... we see ENSO do it very easily....ENSO alter the global precip very easily, yet, global increase in sea levels substantially somehow did NOT increase precipitation at all?

Precipitation has been DECREASING for 35 years!

[tacoman25]

NO it's not, as I've explained 3 times now Precip is far more variable than temperature relative to the expected magnitude of global trends. You need far more data to derive statistically significant trends. Instead, we have less data.

Fair enough, however your logic about the precip data lacking in the Arctic was undeniably ironic considering your opinions about GISS Arctic data.

[skierinvermont]

Most importantly, perhaps, why did you not start arguing about the "inadequacy" of the precip network until you discovered that the trend didn't match expectations?

Actually I said that they contained large errors BEFORE I even knew what the theoretical expectation was. Look at the timestamps on these two posts. In the first I say the error bars are extremely large. In the second, which I wrote after the first, I post my discovery of what the theoretical expectation is.

Just a little too eager there. Yet again someone making up things. It seems the tables have turned.

Why did you falsely accuse me of something I did not do?

I imagine other posters are eagerly jumping on board too now...

I imagine someone will now accuse me of knowing the theoretical expectation and pretending I didn't anticipating that somebody would accuse me of what you just did.

These are the types of constant baseless and rude accusations I have to put up with and people wonder why I get pissed.

It's also worth noting that the error bars on the precipitation graph are extremely large.

The CRU and GHCN 1901-2005 precipitation data have trends of 1.1 +/- 1.5mm/decade and 1.08 +/-1.8mm/decade respectively. So there's a slight positive trend but the error bars are twice the magnitude of the trend itself.

The 1951-2005 trends are about -4 +/- 4.1mm/decade. So again, very large error bars. slight negative trend.

There are also other datasets with different trends and large error bars.. so this data should be used with extreme caution or not really used at all.

http://www.ipcc.ch/p.../ch3s3-3-2.html

      Precipitation Trend (mm per decade) 
Series  	1901–2005  	1951–2005  	1979–2005 
PREC/L 			–5.10 ± 3.25a  	–6.38 ± 8.78a 
CRU   	1.10 ± 1.50a   	–3.87 ± 3.89a   	–0.90 ± 16.24a 
GHCN  	1.08 ± 1.87  	–4.56 ± 4.34   	4.16 ± 12.44 
GPCC VASClimO 			1.82 ± 5.32b   	12.82 ± 21.45b 
GPCC v.3 			–6.63 ± 5.18a  	–14.64 ± 11.67a  
GPCP      			–15.60 ± 19.84a 

OK I looked it up .. precipitation is supposed to increase. The general pattern is more in the tropics, less in the subtropics, and more in the high latitudes. More precip in the high latitudes has been observed and is statistically significant.

Obviously there hasn't been a large enough change in precip in either direction, at least not large enough for our measurement systems to detect.

[WeatherRusty]

More moisture availability? Why are some of the wettest years on record cold years then?

Or what exactly are you arguing? Why would a warmer year enhance the possibility of heavy snows?

I am using nothing better than my logic, for what that's worth. Warmer climates produce greater precipitation amounts when there is a source of moisture than cold climates or environments. In general a warm maritime airmass will contain high precipitable water and the warmer it becomes the more water it can hold. When atmospheric dynamics are favorable there will be more water to be squeezed out. When the warmer air clashes with polar air or arctic air it can snow and snow heavily.

I mean this is just common sense from a meteorological perspective.

[tacoman25]

Skiier, it was too obvious.

1. You agree that Bethesda's graph is accurate and there does not appear to be an increasing trend in global precip.

2. You point out the error bars.

3. You concede that an increase in precip is expected with AGW.

4. You argue that it is impossible to deduce a meaningful trend with the available data.

That was the exact order of your posts and thought process.

[skierinvermont]

Skiier, it was too obvious.

1. You agree that Bethesda's graph is accurate and there is no longterm, discernible trend in global precip.

2. You point out the error bars.

3. You concede that an increase in precip is expected with AGW.

4. You argue that it is impossible to deduce a meaningful trend with the available data.

That was the exact order of your posts and thought process.

Actually #2 should read as

"extremely large error bars".."the data should be used with extreme caution or not really used at all"

DIRECT QUOTE OF MYSELF. Before I even knew what the theoretical expectation was. Seriously.. stop harassing me.

[tacoman25]

I am using nothing better than my logic, for what that's worth. Warmer climates produce greater precipitation amounts when there is a source of moisture than cold climates or environments. In general a warm maritime airmass will contain high precipitable water and the warmer it becomes the more water it can hold. When atmospheric dynamics are favorable there will be more water to be squeezed out. When the warmer air clashes with polar air or arctic air it can snow and snow heavily.

I mean this is just common sense from a meteorological perspective.

Then why does precipitation increase when the tropics (and then land masses) cool with La Nina?

[tacoman25]

Actually #2 should read as

"extremely large error bars".."the data should be used with extreme caution or not really used at all"

DIRECT QUOTE OF MYSELF. Before I even knew what the theoretical expectation was. Seriously.. stop harassing me.

Doesn't change a thing. One step clearly led to the next, and you clearly sought to discount the evidence once you discovered it did not show the expected trend. Don't accuse me of harrassing you. I'm simply pointing out the obvious facts, here.

By the way, how are we able to accurately guage global water vapor, but not global precip?

[BethesdaWX]

huh? Absolutely not....provide me some reference. Warming of the oceans........at the magnitude we've seen..........should have produced a MAJOR rise in precipitation if it is indeed true... we see ENSO do it very easily....ENSO alter the global precip very easily, yet, global increase in sea levels substantially somehow did NOT increase precipitation at all?

Precipitation has been DECREASING for 35 years!

skier im waiting for your evidence. you have absolutely no idea what the heck you're talking about.

[WeatherRusty]

Then why does precipitation increase when the tropics (and then land masses) cool with La Nina?

I have no idea! On second thought, I do have an idea. Maybe more intense precipitation occurs in general during warmer events, while lesser intense precipitation but longer duration events occur when it is cooler?

Oh, and one other thing. During La Nina convection is suppressed in the Nina area. So maybe it is raining less over the Pacific while the Nina pattern directs more storminess over land.

[BethesdaWX]

I have no idea! On second thought, I do have an idea. Maybe more intense precipitation occurs in general during warmer events, while lesser intense precipitation but longer duration events occur when it is cooler?

Oh, and one other thing. During La Nina convection is suppressed in the Nina area. So maybe it is raining less over the Pacific while the Nina pattern bring more storminess over land.

Uhhh, la nina cools the global temperature...yet global precip increases. Don't isolate the pacific.

[skierinvermont]

Doesn't change a thing. One step clearly led to the next, and you clearly sought to discount the evidence once you discovered it did not show the expected trend. Don't accuse me of harrassing you. I'm simply pointing out the obvious facts, here.

By the way, how are we able to accurately guage global water vapor, but not global precip?

I discounted it before I knew what the theoretical expectation was. I am saying the exact same thing (word for word) that I said before as I am saying now. The data should be used with extreme caution or not really used at all.

[skierinvermont]

skier im waiting for your evidence. you have absolutely no idea what the heck you're talking about.

The warming of the global oceans is not supposed to cause a large enough increase in precipitation to be detectable with our current inadequate observation network.

[BethesdaWX]

The warming of the global oceans is not supposed to cause a large enough increase in precipitation to be detectable with our current inadequate observation network.

Not true

I want some evidence, give a me a link from the IPCC saying this...anyone.

ENSO does it, PDO does it...A "massive global sea level warming" would do this as well, the ocean holds so much energy, the water cycle would have to gain momentum.

http://www.waterencyclopedia.com/Ge-Hy/Global-Warming-and-the-Hydrologic-Cycle.html

Skier...learn

[tacoman25]

I have no idea! On second thought, I do have an idea. Maybe more intense precipitation occurs in general during warmer events, while lesser intense precipitation but longer duration events occur when it is cooler?

Oh, and one other thing. During La Nina convection is suppressed in the Nina area. So maybe it is raining less over the Pacific while the Nina pattern directs more storminess over land.

Well, theories abound for sure, but I just don't see any evidence that currently indicates AGW is leading to bigger/more severe storms and more precipitation.

[tacoman25]

I discounted it before I knew what the theoretical expectation was. I am saying the exact same thing (word for word) that I said before as I am saying now. The data should be used with extreme caution or not really used at all.

And after you found out there was no increasing trend. And we all suspected that there was supposed to be more precip, that would seem to make sense with more water vapor.