Guest post by Dr. Richard Keen
The winter of 2009-2010 was a memorable one in the Northeast and Mid-Atlantic states, with locations like Philadelphia enjoying multiple massive snow storms that led to record totals for the winter. As with all exceptional weather events of late, the usual suspects blamed the occurrence on global warming. In a NOAA press release reported in USA Today (http://www.usatoday.com/weather/climate/2010-07-15-heat-record_N.htm), Jay Lawrimore stated that…
Heavy snow, like the record snows that crippled Baltimore and Washington last winter, is likely to increase because storms are moving north.
To which I commented on “Watts Up With That” on July 16, 2010 ( http://wattsupwiththat.com/2010/07/16/a-spot-check-on-noaas-hottest-so-far-presser/ ) that Lawrimore’s remarks show a complete lack of understanding of weather (which makes up climate).
Anyone who spends a few winters on the East coast knows that snow there is generally caused by lows off the coast, and if the storms move north (as Lawrimore claimed), Baltimore, Philadelphia, NYC et al. find themselves in the warm sectors of the lows, and enjoy warm southerly winds and rain.
That’s the theory; how about some data to show that a warmer climate should lead to less snow, not more. The data are easy to find and interpret. More than a century of winter snow totals and average winter temperatures (December-January-February) are posted on the NWS Philadelphia web site. Seasonal snow totals in Philadelphia are dominated by the occurrence (or non-occurrence) of large snow events (i.e., the snowiest winters have two or three major storms, and the least snowy winters had none). Here’s some charts and correlations.
Chart 1 compares yearly winter snow totals (in blue) with winter mean temperatures (in red). The small circles are for individual winters, and the heavy lines are 30-year running means (since climate is defined by some, such as the WMO, as a 30-year average). The winter temperatures are plotted upside-down to show the correlation better. And the correlation is that warm spells, like those in the 1930s, 1950s, and 1990s, have less snow overall than cold epochs like the 1900s, 1910s, 1960s, and 1970s. Note that the 30-year running means are plotted and the end of each 30-year period, so while the 30-year means are shifted a bit from the highs and lows of the annual values, the 30-year curves for snow and temperature line up together. Also note that over 126 years, Philadelphia’s winters are not getting warmer or colder, and there’s not much change in snowfall.
Chart 2 is a direct comparison of yearly snowfall with winter temperatures. The correlation coefficient (square root of R2) is greater than -0.5, which is not bad for anything in climate. It clearly shows a trend for more snow during colder winters, and less snow during mild winters. Philadelphia’s average annual snow fall is 20.5 inches, and the coldest winters produce about twice that amount, while the warmest winters are almost snowless.
The occurrence of snowy and less snowy winters during cold and mild winters is summarized in the table below. Although half of the winters are warmer than the median temperature (of course!) and half are colder, and half of the winters are snowier than median and half are less snowy, the co-occurrence of snow vs. temperature is not so even.
There are several ways to describe the relation between winter temperature and snowfall….
- Colder winters are three times more likely to be snowier than the median.
- Snowy winters are three times more likely to be cold.
- Warm winters are three times more likely to have less snow than the median.
- Less snowy winters are three times more likely to be mild.
One way the relation between snowfall and winter temperature CANNOT be described is that warmth leads to more big snowstorms and greater total winter snowfall.
By the way, I did this analysis for Philadelphia because it’s where I was raised and learned about weather before moving to Colorado. The warmers will no doubt raise their usual charge of “cherry-picking” when inconvenient data shows up. I challenge them to examine others locations in the northeast to find one they can “cherry pick” to support their claims. Until they do, the recent large snowstorms stand not as a symptom of global warming, but as yet another indication that global warming may not be happening at all.
In that picture of a snow covered north eastern USA, Massachusetts seems to be spelled Massassachussetts.
Looks like snow causes cold weather.
In the same way that CO2 causes warming, despite ice core data show it is the other way around.
Kevin says:
January 5, 2011 at 7:03 am
Man, I hope that was a joke?
RockyRoad says:
January 5, 2011 at 4:40 am
Actually, if you think about, it the ‘cold’ weather does bode well for their carbon taxing schemes because it means we use more fuel and they get more revenue from the tax! The bar-stewards………….
Anthony and associates, happy new year. Glad to see that the home fires (WUWT’s sock-it-to-’em-with-data-style) burn as brightly as always, especially in this cold, and getting colder, winter in the NoHemisphere.
I have a question about the dumping of snow that goes beyond cold=snowier, provable by the data and analytic charts. In California, climate-cold seems to equal wet over the long run. E.G., during warm periods like the MedWarmPeriod we can expect even 100s-years droughts, I am interested in the warm-wet, cold-dry truths over the whole of the globe even though it seems to be different in CA, at least during the Holocene. I wonder if when the NoH changes from warm to cold (both PDO and AMO and minimal Sun) as the data suggests today, that perhaps at first there is a great dump of evaporation from warmth whether as snow or rain (Australia-SoHemp). Any long-term data or studies suggesting this truth to changing warm-to-cold conditions? And can we expect quite a “dump” for a number of years as the atmosphere “dries out”?
everything is due to global warming, you unintelligent fools.
P. Solar says on January 5, 2011 at 4:57 am :
“Most evaporation takes place over the oceans so that is where the warming is relevant.”
The wind is the mechanism that transport water out of the oceans onto the land even when the water is quite cold. The wind speed is due to the pressure differential between adjacent high and low pressure cells.
An increase in air temperature from 14 to 15 deg C causes the specific humidity to increase about 6%. This is an increease of the specific humidity from 12.1 to 12.8 g of water vapor per cubic meter for 100% specific humidity which only occurs when there is rain, snow or thick fog.
Air pressure has a far greater influence on changes in specific humidy and weather than a slight change in temperature. High pressure cells have dry air, and low pressure cells have moist air.
Turn on the TV and watch the weather report and ask yourself, “What has CO2 got to due with movement of the large masses of air and clouds?” The correct answer is zip.
I’ve just noticed the BBC’s envrio correspondent Richard Black is tying himself up in trying accept reality, or is he trying to reposition himself?
http://www.bbc.co.uk/news/science-environment-12119329
So it wasn’t as wet, that’s alright then we’ll ignore all that inconvenient white stuff that screwed up the airports, railways and roads.
To say that warming causes more cooling sounds like the work of Maxwell’s Demon.
Tell me, do you think it is possible that the snow fell on the north more southerly than say the Arctic circle as would be expected? And if it could, could the cause of that be because a a minuscule shift in the tilt of the earth as it rotates the sun? Assuming the tilt is 20 degrees that results in an 40 degree shift over the year. . . . 20 degrees in winter solstice and another 20 degrees at summer solstice.
Further, your have a relative apogee and perigee . . . . ie. like flying it would be a head wind and a tail wind . . . that may change which to me coincides with the 280 year “sun” cycle.
Physics, for the purpose of math . . . assumes the sun stationary, which it is not.
It’s how I become confused because there really is no stationary point in the reality of a realistic model.
Incidentally, the apocryphal book of Enoch is the first place I ever read about a Sun cycle. . . . Enoch was the ‘OMA” pa of Noah . . . he was taken to the heavens by “angels” and lived 360 years before he was taken to “the heavens” never “dying”.
I bring this up because I like to “give credit where credit is due!” The book gave me pause to ponder!
Since the correlation of snow is allegedly to “global warming” – not Philly warming, wouldn’t it be better to correlate Philly snowfall with global temps – which I am suspecting would show no statistically significant correlation & completely kill the Nor’easter – GW connection hypothesis. If you agree, I would be very interested in seeing that cross-plot as well
Warmists will continue to throw out their ridiculous assertions, but their myths cannot hold water when analyzed. In light of the fact that the temperature chart for Philadelphia shows cooling since well before 2000, and the global temp anomaly has also been trending down, there is also no argument for this extreme snowfall year to be correlated with temperature increase. Most rational thinkers already know that colder winters are correlated with more snow.
I am anxiously awaiting the warmist reply to this article… if or when they find their needle in a haystack… but am not holding my breath.
Even though most climate realists readily admit there has been some ‘global warming’ over the past century or so, perhaps a rebound from the Little Ice Age, it would appear that every time someone here reports on the temperature history of a specific location, the result is no warming, or very little.
Does anyone else find this odd? At the very least, does it not throw doubt on the concept of a ‘global’ temperature, and on the data and calculations used to derive such a number?
/Mr Lynn
My expert opinion to the headline question: hell no.
Another issue that comes into play is the measurement of the snow in inches, as opposed to water content. Cold temps can “fluff -up” an inch of rain into a foot of snow, while a slightly warmer temp, will reduce it, to six inches of heavier snow, and eventually, back to the point where you get no snow, and just the inch of rain. So two similar storms can produce vastly different outcomes based on which side of the freezing line the precip bombs out. In general, that would support the “colder temps = greater snowfall theory”.
Where do I sign up for my research grant to test this theory? I guess I need to come up with a scenerio where people die a horrible death, if I don’t get paid.
Here in California it’s the reverse – colder winters mean less rainfall, and higher temps correlate to more rainfall.
With “Global Warming” getting it’s name changed to “Climate Change” and now changed to “Climate Chaos” it is fun to point out that what we are really seeing is the climatologists attempting to blame the failure of their climate models on… wait for it… global warming.
Mr Lynn says:
January 5, 2011 at 9:05 am
“Even though most climate realists readily admit there has been some ‘global warming’ over the past century or so, perhaps a rebound from the Little Ice Age, it would appear that every time someone here reports on the temperature history of a specific location, the result is no warming, or very little.
Does anyone else find this odd? At the very least, does it not throw doubt on the concept of a ‘global’ temperature, and on the data and calculations used to derive such a number?
/Mr Lynn”
You took the words right out of my mouth – spooky!!!
I think that, due to the deterministic chaos which ultimately drives our climate system, averaging global temperature is a meaningless exercise which tells us nothing about climate. Only the temperature experienced at a given location means anything to the biosphere, and here in Sunny Sussex UK the temperature is going down with later spring and earlier winters this last few years.
Perhaps the only way we can get anything useful out of temperature measurement is by using the thermometer in our own back yard?
The AGW proponents do themselves a great disservice by linking EVERY SINGLE extreme weather event to global warming or climate change. However, it isn’t just making the connection, but their scientific explanations are usually incorrect, contradictory, or present obvious natural climatological weather patterns as some new climate paradigm that will only get worse as the world warms.
The USA Today article above has many examples – explanation for more lake effect snow or east coast snow storms.
Was 6 ft. of December snow in Syracuse due to Lake Ontario being unfrozen, plus a cold snap? Yes. Does the lake ever freeze over in December? I don’t think so. Was the cold snap due to global warming? Try it, I dare you.
Were any of the three major snow storms on the East Coast last winter due to storms moving “more north”? I’ve lived in the Northeast all of my life, that is a normal weather pattern, with other factors at play to keep the land areas on the cold side of the storm. The arrogance to TWIST explanations of climatological weather patterns as if these are new and due to warming?! Or that warmer air holds more moisture, and that’s how we got more snow! It was an OCEAN STORM – where development was in an area that had been 10 F below average for weeks!
Judah Cohen’s op-ed does the same thing, trying to tell us that Siberian snow-cover, due to less Arctic ice and hence global warming, creates less zonal flow and more meridional flow, thus dumping more cold air over the mid latitudes. This is what happens in the winter!!!
If real climatologists actually did their jobs and performed more case studies to figure out all of the influences playing into these events, we would be much better off in our understanding of climate and closer to understanding any influence that an increase in global average temperature might have (whatever the cause). No, we all prefer one-liners with no scientific basis that point to global warming as the culprit and that things will only get worse.
The pro AGW scientists keep moving the goal posts. Earlier they mostly all agree global warming will make snow and blizzards things of the past. Now they say global warming causes snow storms and blizzards due to the vast amount of moisture because of global warming. That’s a lot of BS.
Now it turns out that the GB Met office got the prediction right and published it.
We now know where Piers got his forecast.
P. Solar says:
January 5, 2011 at 4:57 am
“Dr. Richard Keen, I don’t know if you are intentionally missing the point or just not thinking this through.
…As I understand it, the warmist proposition here is that snow is a form of precipitation and that GLOBALLY warmer temps will lead to increased precipitation in affected areas.
…If conditions in a particular state are such as to cause snowfall this snowfall would be heavier in a warmer world.
…Your analysis neither proves or disproves this hypothesis. Despite the title, you do not address the issue.”
Sorry, I’m not missing the point, and I do address this issue. The data shows that colder equals snowier, so the warmer equals wetter hypothesis simply doesn’t, well, hold water. Remember, Lawrimore et al. said that warmer equals snowier, and that’s wrong.
Tom in South Jersey says:
January 5, 2011 at 4:54 am
“My anecdotal experience has been that all the winters here have nor’easters, but whether we get a good dumping of snow, rain or a mix depends upon whether the low moving up the coast meets up with a cold air mass, or whether it brings warm air from the South with it. The years that we don’t experience heavy snow usually bring heavy rain instead.”
Tom does get the point. There’s plenty of precipitation along the East Coast, roughly 3 to 4 inches per month. In Philadelphia, about one-fifth (or less) of that falls as snow. A 1-inch rain storm is just another rainy day, but with a bit of cold air, that same storm becomes a memorable snow storm. In a location where mean winter temperature is just above freezing, precipitation is not the limiting factor for snow. Cold air is. The cold air is more likely to be involved when…
1. The atmosphere is colder overall, and
2. The Low centers pass south and east of PHL, not farther north as Lawrimore incorrectly states.
During the 1950s, back when people paid attention to synoptic storm tracks, the strongest lows passed up the Appalachians and PHL had wet, rainy winters.
Later, in the 1960s and 1970s the storm track shifted east and nor’easters became more common, and guess what – more snow! And the climate was cooler overall then, too. BTW, this was the subject of my PhD thesis in 1979, so that’s why I’m so noisy about this.
Finally, from 1962-1965 the East underwent its worst drought in history. Average dew points for those years were no lower than normal, so available moisture wasn’t the issue. What caused the drought was an even further shift in the storm track out to sea, dropping rain on the ocean rather than on PHL. For a location that receives most of its precipitation from synoptic weather systems, the amount of rain/snow is not controlled by the overall moisture content of the atmosphere, but by the tracks and intensities of the lows that convert moisture into precipitation.
Great post Dr. Keen, very well put. Anthony and Moderators great job with guest post, we see new commentors here now, My queation is were is Lazy Teenager to spout his dribble on how wrong the good Dr. Keen is, my guess is he got tired of being proved wrong on every turn, Or he is licking his wounds and back to joe romm to get some anwsers to the questions which we know form romm he will be wrong again.
Well thanks for giving us that data, and for your conclusions; which I tend to agree with.
But I would observe: that your second graph; the scatter plot of the Snowfall versus the Dow Jones Factor Temperatures; has all the characteristics of 1/f noise. Data points that are further removed from the general population occur inversely with the frequency, the further they get from the mean. In which case, I don’t think it is legitimate to treat every data point as having the same weight; so a simple RMS fit to a straight line, seems to me to be an exercise in statistical self delusion. If you had 1000 times as many data points in your scatter plot, I might be tempted to believe your statistics; with so few data points, the straight line you plot is hardly likely to indicate any Physical causality. A line with a slope 50% higher or 50% lower than yours; (3:1 slope ratio) could just as easily be as correct as yours.
It is clear to me from your raw data, that the Dow Jones Factor Temperature is proportional to the logarithm of the inches of snowfall; so that the inches of snow double for each decremental decrease in the Temperature; but the scatter plot is so diffuse, that I am unable to determine the Snowfall Sensitivity to better than a 3:1 range; but my best guess would be a 3 deg F decrease in DJF Temperature for each doubling of the inches of snowfall.
Your essay demonstrates why it is that we get a new 150 year storm about every five years; people forget what the weather was REALLY like after about five years.
socalmike says:
January 5, 2011 at 9:19 am
“Here in California it’s the reverse – colder winters mean less rainfall, and higher temps correlate to more rainfall.”
There are regional differences in the temperature – snow correlation, to be sure. I live in the hills of Colorado where we get 40-inch snow storms every other year on average. Since 1982, 9 out of 12 storms occurred during colder than average snow seasons, and nearly all occurred during el Niño (which tends to be cold in Colorado). In the Pacific Northwest, snow favors La Niña, which brings them colder winters. Again, it’s all to do with storm tracks.
“”””” socalmike says:
January 5, 2011 at 9:19 am
Here in California it’s the reverse – colder winters mean less rainfall, and higher temps correlate to more rainfall. “””””
The recent spectacular river of rain that blasted across California completely missing the Baja, and on into the plains States, supposedly came straight up from the tropics; which has that mysterious blue swath along the equator in the global SST anomaly graph (go figure).
But it generally does seem to be true that La Nina promises new droughts to California; rather than more rain than we know what to do with. I suspect circulation pattern changes are the cause rather than so much temperature changes; but I know virtually nothing about circulation patterns; so I’ll leave it up to you PDO, AMO, SRO experts to explain.