Past IEM Features tagged: nca5
With the release of the National Climate Assessment (NCA5) this week, the IEM daily feature has been looking at some of the trends denoted in the report. Today's feature highlights Figure 2-4, which presents a map of annual, winter, and summer season change in total precipitation. The featured chart presents the unofficial IEM spatially averaged precipitation annual total value for Iowa. A simple long term mean is plotted, along with a 30 year trailing average and a recent 30 year average. A number of very wet years over the past two decades has helped to push the trend upward for Iowa, but this year will very likely come in well below average. Climate change is not a simple, linear, and constant change in some climate variable each year, but is a nuanced and complicated interplay between many factors that yields some bulk change over time.
The US National Climate Assessment 5 (NCA5) was released yesterday. It summarizes climate change risks, impacts, and responses. There is a dedicated chapter for the Midwest and figure 24-3 highlights the change in last spring date of sub-29°F over the region. While much of the region is shown to be having an earlier-in-spring date of last sub-29°F temperature, a good chunk of Iowa is shown to be having later dates. An example of such is Cedar Rapids as shown by the featured chart. The NCA5 denotes that large variability exists and a confident trend isn't necessarily found over the region. This featured chart certainly affirms that with a correlation coefficient of the simple and linear long term trend close to nil. But a visual inspection of recent years for this site shows the vast majority of them having a later date than the long term average of 13 April. Will hopefully crank out a few more features comparing NCA5 figures with what you can generate on the IEM website.