Snow Coverage: Normal or Not?

While I have been off there has been lots of news about snowy weather around the world.  From snow in Australia during the summer to the major blizzards that have been hitting Europe and Eastern North America.  This news is being used to support the newly christened “climate disruption” and also used by many to say what a fake global warming is.  The interesting fact is that this winter is statistically speaking, very normal so far.

The amount of snow that has fallen in the Northern Hemisphere (NH) has not changed in the past 40 years.  Since 1972 there are good records on how much of the land is covered by snow over the course of the year.  There is no trend at all in the overall amount of land covered by snow.

The Inconvenient Skeptic

The Northern Hemisphere snow coverage since 1972.

The only difference is that this was the earliest that the snow coverage reached 44 million km2 this early since 1992.  That value is almost always reached by week 51.  So the snow was a couple of week earlier than normal, but that is weather.  There is nothing abnormal about the snow being this early either.

The Inconvenient Skeptic

NH Snow coverage for week 49

The snow is higher than average, but only slightly higher than 1 standard deviation for the time of year.  There is a lot of variation in the spring and fall for the total snow.  For people that live in the NH that should be no surprise.  Early snows happen and it never seems to happen at the same time of year.  Heavy snow in October is not unusual in many places, even if it melts in November.  That type of weather causes a higher variation in the snow coverage in the fall and spring.

What is most interesting is how very normal the snow coverage has been.  From 2009-current the average snow coverage is normal.  Perfectly and absolutely normal.  Some weeks more, some weeks less.  Here is what it looks like compared to the average.

The Inconvenient Skeptic

Northern Hemisphere snow coverage for the past two years

When the snow hits suddenly and fast it causes many disruptions and isn’t fun for those that are traveling, but it also happens to be perfectly normal.  Weather determines the exact location and the exact timing.  The location and timing was bad for holiday travel, but other than that this winter is very much like all the winters in the past 40 years.

The Inconvenient Skeptic

Snow extent anomaly for Dec 27, 2010. Blue represents places that currently have snow cover that normally do not. Red represents places that normally have snow, but currently does not have snow.

Posted in Anomaly and Climate by inconvenientskeptic on December 28th, 2010 at 12:30 pm.


This post has 6 comments

  1. Malaga View Dec 29th 2010

    this winter is very much like all the winters in the past 40 years.

    That very much depends upon where you live… averages just obscure a multitude of sins… the Weather I experience is the Climate I experience… so Weather is Climate – punto!

    Ignore The Day At Your Peril

    Will This Be The Coldest December In England’s History?

  2. Malaga View Dec 29th 2010

    Or to put it another way….the Rutgers University Departure from Normal – November 2010 shows vast areas around the Artic Circle where November was NOT normal

  3. inconvenientskeptic Dec 29th 2010


    Certainly there are locations that are colder than average and places that have snow that usually don’t.

    But that is balanced by places that don’t have snow that usually do. I have updated the legend for the map to clarify that it shows both.

    The western US started cold, but has warmed up while the East has frozen. It rained here all last night, but no snow.

    So yes the locations are odd this year, but that is weather. That the amount of snow is stable over the past 40 years shows that overall, things have remained normal.

  4. Malaga View Dec 29th 2010

    Mmmmm… I am happy to buy into the concept of Climate Zones with typical weather patterns… Med Climate – Hot, dry summers and cool, wet winters… beyond that usage the term Climate has become meaningless… and Climate Science has become an oxymoron…

    I will stick with concept that Weather is Climate… so that the climate changes as the weather changes… and the Sun drives the weather through daily, seasonal, solar and Milankovitch cycles.

    I will avoid averages, especially global averages, as they generally meaningless and are generally used to obscure the detail.

    But I agree: the locations are odd this year which makes this an odd year… weather seems to make a habit of being odd.

  5. Richard111 Jan 1st 2011

    Odd weather indeed. I live in Milford Haven, West Wales, and I harvest my rainwater. This is the first year they have frozen up! I use cubic metre tanks. If I must insulate all four tanks I have a problem!

  6. peterhodges Jan 2nd 2011

    the high sierra has the most snow ever for this time of year.

    including this year, the top 4, and 5 of the top 10 snow years, are in the last ten years.

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