2012 Snow Cover Starting Out Very Low

January 18, 2012

After a record-breaking year of extreme weather in the US in 2011 (which was already apparent when we ran the TipSheet of Aug. 31, 2011), snow cover is following suit. For instance, 15% of the country had snow cover on Jan. 9, 2012. That compares to 49% on the same date in 2011, and 63% in 2010. From 2004-2009, the vacillation was much less, ranging from 26-49% for that date in each year.

Just as the low snow coverage this year is drawing media attention, the high numbers for 2010 and 2011 caught the attention of many as snow cover occurred in 49 states on a few days in January 2011 and all 50 states in February 2010. Those are considered by NOAA to be fairly rare events, though adequate long-term records aren't available.

Weather always varies considerably from year to year, and the current timeframe of snow cover data — which is derived from satellite and ground observations fed into a predictive model — is far too short to know whether recent roller-coaster snow coverage is unusual in the context of centuries.

That said, here's NOAA's assessment of how the snow cover on Jan. 9, 2011, compared to the short-term normal.

Snow cover has many implications for people, as reflected in the growing concern this year by many owners and operators of ski areas and related businesses across the country whose facilities are short on snow; similar concerns by many farmers who rely on snowmelt for winter and spring soil moisture and summer irrigation; firefighters and residents battling major fires in unusual locations in the middle of winter; people trying to cope with smothering blizzards in areas at the other end of the extreme snow spectrum this year; or local officials trying to figure out how to budget from year to year for snow removal amid so much snowfall variability.

To begin to look at the snow cover topic in more depth, one starting point is NOAA's National Operational Hydrologic Remote Sensing Center. For a quick visual overview of current and recent snow cover areas in the US and much of Canada and Mexico (and even the entire northern hemisphere if that's your beat), see:

For extensive current and recent historical data on the nation and regions of interest to your audience, see:

The data include information such as the national percentage of snow cover on a given date, the same information for the date a month earlier, average, minimum, and maximum snow depths, the amount of water in the snow, and other details.

You can search any date from 2003-2012, nationally and for 18 regions. There are maps for many categories of information, including snow depth, snowpack temperature, and other factors. Each map can be structured in a variety of ways to meet your needs.

Other resources include:

Despite the lack of long-term data, snow-cover occurrence, whether high or low, is another piece of information to keep in mind as you cover the topic of whether a specific extreme weather event of any type (downpour, drought, flood, tornado, hurricane, blizzard, etc.) may be related to climate change. Such events are generally predicted to occur more frequently as climate shifts, but until recently most people shied away from making any definitive link between a single event and climate change.


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