Major Snows Not due to AGW

[BethesdaWX]

http://wattsupwiththat.com/2011/02/17/regarding-thermodynamics-and-heat-transfer-why-al-gore%e2%80%99s-comments-to-bill-o%e2%80%99reilly-at-fox-news-are-wrong/#more-34175

[skierinvermont]

http://wattsupwithth...ong/#more-34175

Al Gore got the mechanism wrong, but that doesn't mean that global warming would not cause more heavy snowfalls in certain areas. Of course attributing single events to AGW is just silly.

The author of this WUWT post conveniently fails to mention that the global oceans and land surfaces have warmed dramatically, and that therefore via the Clausius-Clapeyron equation atmospheric water vapor is expected to rise. Global measurements confirm this theoretical expectation.

[tacoman25]

Al Gore got the mechanism wrong, but that doesn't mean that global warming would not cause more heavy snowfalls in certain areas. Of course attributing single events to AGW is just silly.

The author of this WUWT post conveniently fails to mention that the global oceans and land surfaces have warmed dramatically, and that therefore via the Clausius-Clapeyron equation atmospheric water vapor is expected to rise. Global measurements confirm this theoretical expectation.

Any evidence that global precipitation has risen as a result?

And is a .8C rise over the past 100 years enough to make a significant difference in water vapor?

[BethesdaWX]

Al Gore got the mechanism wrong, but that doesn't mean that global warming would not cause more heavy snowfalls in certain areas. Of course attributing single events to AGW is just silly.

The author of this WUWT post conveniently fails to mention that the global oceans and land surfaces have warmed dramatically, and that therefore via the Clausius-Clapeyron equation atmospheric water vapor is expected to rise. Global measurements confirm this theoretical expectation.

The snows that have crippled the northern hemisphere have not been due to warming temps...given that global temps have been running Cool this winter.....and 1998, and other warm years in the past decade, did not feature these winters. This has been caused by HLB.

PDO flip in 2007 sparked the return of the colder winters. Satelllite Data.....Years 2008, 2009, 2010, & now 2011.....2008 & 2011 , or 50%, will come in Below avg.......... 2010 was 2nd warmest, and 2009 was slightly above avg with the El Nino coming on.

[WeatherRusty]

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?

[BethesdaWX]

Any evidence that global precipitation has risen as a result?

And is a .8C rise over the past 100 years enough to make a significant difference in water vapor?

More like a combination of factors, Water Vapor, Sun, MagF, CO2/Emissions, Deep Ocean currents, GCC, have had an effect on the global temperature.

[BethesdaWX]

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?

These Harsh Snows correlate to the AO/NAO, not Global Temperature.

As I anticipated, the -PDO base change in 2007 has brought with it the return of these harsh winters. These will continue.

[LocoAko]

1297971280[/url]' post='477373']

Any evidence that global precipitation has risen as a result?

And is a .8C rise over the past 100 years enough to make a significant difference in water vapor?

I'm too lazy to do the calculation myself, but it says here http://www.realclimate.org/index.php/archives/2006/06/on-a-weakening-of-the-walker-circulation/ that it is about 7% for every 1C of warming. So yes?

[WeatherRusty]

Any evidence that global precipitation has risen as a result?

And is a .8C rise over the past 100 years enough to make a significant difference in water vapor?

Water vapor levels are supposed to increase by 7% per 1C increase in temperatures. This is based on the Clasius Clayperon equations and all climate models build this in (6% to 8%). Water vapor should also increase a little more at the tropopause (300 mb) than at the surface.

The atmosphere's water vapor content has increased by about 0.4 kilograms per square meter per decade since 1988 if I recall correctly.

[skierinvermont]

The snows that have crippled the northern hemisphere have not been due to warming temps...given that global temps have been running Cool this winter.....and 1998, and other warm years in the past decade, did not feature these winters. This has been caused by HLB.

PDO flip in 2007 sparked the return of the colder winters. Satelllite Data.....Years 2008, 2009, 2010, & now 2011.....2008 & 2011 , or 50%, will come in Below avg.......... 2010 was 2nd warmest, and 2009 was slightly above avg with the El Nino coming on.

They were still comparatively very warm years. Nobody is saying that a specific storm is 100% directly attributable to AGW. What is saying is that the frequency of 20" snowstorms in NYC might increase from 1 every 20 years to 1 every 17 years. It's basically just the climate zones moving northwards.

As you can see the frequency of heavy snows increases farther south where it is warmer. To take this to the extreme, very little heavy snow falls in the arctic.

[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?

1998 was the warmest year on record, yet it didn't feature anything like the record-breaking snowstorms that have occurred in recent years.

The majority of the "blame" for the big snowstorms seen over parts of the NH the past couple winters clearly should go to the major blocking patterns that have been seen, which have nothing to do with AGW.

[BethesdaWX]

It follows the AO/NAO, the snowstorms have no correlation to global temps, (aka,the major period of snowstorm in the late 1800's was no different from todays)....you think the big time snowstorms in the late 1800's were any different than these? No sir. However, that was a time of -NAO/-AO.

The AO/NAO have generally been trending positive until recently.

[tacoman25]

They were still comparatively very warm years. Nobody is saying that a specific storm is 100% directly attributable to AGW. What is saying is that the frequency of 20" snowstorms in NYC might increase from 1 every 20 years to 1 every 17 years. It's basically just the climate zones moving northwards.

As you can see the frequency of heavy snows increases farther south where it is warmer. To take this to the extreme, very little heavy snow falls in the arctic.

Sorry, but I don't think that works very well as an explanation for the unusually severe winter storms seen in the Southern U.S. recently.

[tacoman25]

Water vapor levels are supposed to increase by 7% per 1C increase in temperatures. This is based on the Clasius Clayperon equations and all climate models build this in (6% to 8%). Water vapor should also increase a little more at the tropopause (300 mb) than at the surface.

The atmosphere's water vapor content has increased by about 0.4 kilograms per square meter per decade since 1988 if I recall correctly.

Ok, so assuming we've seen a 5-6% increase in water vapor over the past 100 years, how should that translate to increased precipitation? And is there any evidence for increased precipitation?

[BethesdaWX]

Sorry, but I don't think that works very well as an explanation for the unusually severe winter storms seen in the Southern U.S. recently.

The "climate zones moving north", in large part, was a response to the +trend in the AO/NAO in the last several decades...now that things have reversed, we've seen the lower lattidues return to winter snows.....even in a Major La Nina

[skierinvermont]

Yes the high frequency of heavy snows during the late 1800s in the northeast probably negates any sort of trend. The effect is probably too small to detect at this point. As I said before, it's the difference between once very 20 years and once every 18 years.. which is unlikely to be detected.

I would expect that as the climate warms further the frequency of heavy snows at a place like Burlington or Caribou or Montreal would increase noticeably. And the frequency in places like DC southwards would decrease. Like I said, it's basically just the climate zones moving northwards.

[Isotherm]

I've heard this assertion numerous times over the course of the winter and it's beginning to get annoying -- "The major snows are due to global warming, because warmer temperatures mean more moisture is available in the atmosphere, and thus snowstorms are more intense, producing larger snowfall totals."

Problem is the record northern hemispheric snows this winter have occurred w/ precipitable water values BELOW normal, meaning there's less moisture in the atmosphere (which makes sense logically since it's been quite cold in Europe, Asia, and North America).

[skierinvermont]

Sorry, but I don't think that works very well as an explanation for the unusually severe winter storms seen in the Southern U.S. recently.

Good. I wasn't trying to explain short term weather variability with AGW.

I am saying that in the long term (HEAVY EMPHASIS since you missed this the first time), the climate zones will move northwards. Which means more heavy snows for Burlington, Caribou, Montreal northwards, and less heavy snows for DC southwards. In between, we might witness an increase in 24-hr 20"+ storms but a decrease in 10-20" storms.

Your comment is pretty flippant and not relevant to what I was saying.

[tacoman25]

Yes the high frequency of heavy snows during the late 1800s in the northeast probably negates any sort of trend. The effect is probably too small to detect at this point. As I said before, it's the difference between once very 20 years and once every 18 years.. which is unlikely to be detected.

I would expect that as the climate warms further the frequency of heavy snows at a place like Burlington or Caribou or Montreal would increase noticeably. And the frequency in places like DC southwards would decrease. Like I said, it's basically just the climate zones moving northwards.

Except that this would mean NYC should start seeing the climate of DC, and DC should start seeing the climate of Raleigh, and Montreal should start seeing the climate of Albany.

But what has happened the past couple winters doesn't resemble that at all, and should not be used as evidence for "shifting climate zones". It's clearly the NH blocking patterns that are mainly responsible.

[tacoman25]

Good. I wasn't trying to explain short term weather variability with AGW.

I am saying that in the long term (HEAVY EMPHASIS since you missed this the first time), the climate zones will move northwards. Which means more heavy snows for Burlington, Caribou, Montreal northwards, and less heavy snows for DC southwards. In between, we might witness an increase in 24-hr 20"+ storms but a decrease in 10-20" storms.

Your comment is pretty flippant and not relevant to what I was saying.

And given that this thread is about an AGW proponent tying in short term events to longterm trends, how is your comment relevant?

And NYC should not be seeing bigger snowstorms more frequently if the climate zones are shifting northward. Think about it.

[skierinvermont]

And given that this thread is about an AGW proponent tying in short term events to longterm trends, how is your comment relevant?

And NYC should not be seeing bigger snowstorms more frequently if the climate zones are shifting northward.

Forgive me, I interpreted the topic slightly more generally than the antics or Mr. Gore. You'll note that my first post started with:

Al Gore got the mechanism wrong, but that doesn't mean that global warming would not cause more heavy snowfalls in certain areas. Of course attributing single events to AGW is just silly.

[BethesdaWX]

I've heard this assertion numerous times over the course of the winter and it's beginning to get annoying -- "The major snows are due to global warming, because warmer temperatures mean more moisture is available in the atmosphere, and thus snowstorms are more intense, producing larger snowfall totals."

Problem is the record northern hemispheric snows this winter have occurred w/ precipitable water values BELOW normal, meaning there's less moisture in the atmosphere (which makes sense logically since it's been quite cold in Europe, Asia, and North America).

Exactly, very cold airmasses cannot hold much moisture at all. The -NAO/-AO supressing the storm track is what causes the snows....no correlation to global temps.

NH snowcover has not trended anywhere, its hilarious to watch these folks "invent" data right out of their heads!

Warming temps have absolutely nothing to do with NH snowcover anomalies.

Fall Snowcover

[tacoman25]

Forgive me, I interpreted the topic slightly more generally than the antics or Mr. Gore. You'll note that my first post started with:

Your logic still does not make sense. NYC should not be seeing more frequent heavy snows, and neither should DC, if the climate zones are shifting northward.

Same goes for Dallas, OKC, Atlanta, etc.

[skierinvermont]

And given that this thread is about an AGW proponent tying in short term events to longterm trends, how is your comment relevant?

And NYC should not be seeing bigger snowstorms more frequently if the climate zones are shifting northward. Think about it.

Baltimore has 8 snowstorms >20", NYC only has 6

Baltimore has 4 24-hr snowtorms of 20"+, NYC only has 3.

[tacoman25]

And again, no one has answered the elephant-in-the-room question: if there is evidence for increased water vapor, what about increased precip? This whole argument hinges on that.

[BethesdaWX]

Baltimore has 8 snowstorms >20"

Baltimore has 4 24-hr snowtorms of 20"+, NYC only has 3.

If snowcover was decreasing further south due to warming, we'd see a drop in NH snow cover anoms

[tacoman25]

Baltimore has 8 snowstorms >20", NYC only has 6

Baltimore has 4 24-hr snowtorms of 20"+, NYC only has 3.

So you're telling me that as a general rule, the further south you go on the East Coast, the higher number of big snowstorms? Because that's what your logic depends on.

[skierinvermont]

Your logic still does not make sense. NYC should not be seeing more frequent heavy snows, and neither should DC, if the climate zones are shifting northward.

Same goes for Dallas, OKC, Atlanta, etc.

I didn't say DC would. I said specifically that DC would not.

[BethesdaWX]

And again, no one has answered the elephant-in-the-room question: if there is evidence for increased water vapor, what about increased precip? This whole argument hinges on that.

Yep.......no trend in global precip. Adjusted temps have never made sense.....

Sometimes I have urge to use the Precipitation data as the temperature data. They correlated perfectly until it was adjusted, which is why I don't use the adjusted temps, or surface data in general.

[tacoman25]

I didn't say DC would. I said specifically that DC would not.

And has DC seen a decrease in big snowstorms?