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Posts tagged with Climate

So how does 2012 stack up weather wise?

There has been a lot in the news about the great drought of 2012 and what the high temperatures might be telling us about what is happening to climate. So rather that rely on "some people say" as a source, I decided to check climate data from NOAA to get some perspective on the situation. NOAA has a great time series of statewide data for important weather parameters including average temperatures, precipitation and several measures of drought severity.

First of all how does 2012 stack up so far temperature wise for Kansas?

My firs NOAA data plot shows June's historical temperature data just by itself:

Notice that June just by itself really isn't so extreme historically. But my impression as a biologist who spends a lot of time doors, is that this year HAS been abnormally warm so lets look at year to date historical data shown in my next plot:

This shows a quite different story. As you can see the year to date temperature through June is very extreme. The year to data average temperature for the state is 55 degrees F. The next closest year to date average for Kansas appears to be 1986 at 54 degrees F. Going back to the 1930's, 1934 is the dust bowl year that comes closest at 53 degrees F. So temperature wise- so far this year is historically abnormal. However many of the record highs of the 1930's still stand.

Another concern is of course the several drought and NOAA provides several drought indices. Not being familiar with how these indices relate to each other I chose just to plot the basic Palmer Drought Severity index which uses local temperature and precipitation data to provide an index of drought severity that can be used to examine historical data: Negative values of the index represent more severe local drought conditions.

Notice that 2012 does not even come close in severity to the earlier droughts, including some relatively recent droughts of the 1980's. What is interesting is that the Palmer index suggests that the drought of the mid 1950's was in some respects more intense than the drought of the 1930's.

So the data suggest that yes it has been really abnormally warm so far in 2012. On the other hand the Palmer data suggest that the current drought is not (At least through June) as severe as a number of other droughts we have had.

One problem we have of course looking at historical data is that agricultural practices have changed since the 1930's. Much of the marginal land that was farmed then is not farmed now or is farmed using large scale irrigation. Farmers today tend to use tillage and other conservation practices that that probably are moderating local temperature and precipitation to some degree compared to earlier years. This might explain the greater number of extreme highs during the 1930's when conservation practices were not as widespread.

If you want to have your own fun looking at climate data, check out the NOAA site at:

http://www.ncdc.noaa.gov/temp-and-precip/time-series/

There is a pull menu where you can select your state or region. You can also filter the data in various ways. This is a good way to check one's perceptions of climate change against historical data so you won't have to rely on what "some people say" or the infamous "they say" as a data source!

A link the drought indices is here: http://www.drought.noaa.gov/palmer.html

If you are into looking at extremes in terms of temperature and precipitation weather underground has a link to climate data. Go to www.wunderground.com and select the climate tab. Have fun!

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