Green groups fact checked on MI rainfall claims

The Natural Resources Defense Council (NRDC) in conjunction with the Rocky Mountain Climate Organization (RMCO) released a new report entitled Extreme Storms in Michigan. Apparently, the study documents a significant increase of almost 90 percent of per year frequency of extreme rainfall events defined as two or more inches a day across Michigan over the last 50 years. A blogger at The American Thinker named Sierra Rayne decided to give the study a look and found some interesting results.

According to Ms. Rayne’s review of the data the two groups utilized:

In contrast, using the NOAA National Weather Service (NWS) database, there is not a single climate sub-region in the state (among the Detroit, Flint, Grand Rapids, Lansing, Muskegon, Alpena, Houghton Lake, Sault Ste Marie, and Marquette County areas) that has a statistically significant increasing trend in “the annual frequency of extreme precipitation events – defined as 2 inches or more in a day” over the last 50 years. Not one.

In the Appendix of the NRDC/RMCO report, the authors describe their research methodology and list the “37 analyzed stations” that were the source of their data. Looking at the NOAA-NWS database for the completeness of the annual historical record at some of these stations reveals substantial problems.

For example, at the “Grand Ledge 1 NW” station the NRDC/RMCO used, there was a lack of a complete annual record for the following years between 1964 and 2013 (i.e., the range of the NRDC/RMCO’s study): 1991, 1997, all years from 1999 through 2008 inclusive, 2011, 2012, and 2013. A total of 55 months with incomplete precipitation data exist over this period, and consequently, it is unclear how one could derive a reliable determination and trend analysis of the number of precipitation events of “2 inches or more in a day” for this station.

Ms. Rayne uses charts as well as previous news reports when pointing out the flaws of the eco groups’ research. In the end, none of the areas covered in the study have experienced significant change in rainfall since data being collected on rainfall events began including over the last 50 years. Simply put, save for the Little Ice Age, extreme weather events are not happening and the weather we are experiencing is no different than in the past. If you look at the weather records there is no trend of extreme events of any kind. This is something the NRDC and RCMO chose to ignore.