If you’ve been keeping track of intense downpour events for the past 50 years as NOAA has, you’ve noticed that they are more frequent in Pittsburgh than they used to be. This will only get worse.
According to NOAA’s National Climate Assessment, by mid-century the frequency and intensity of heavy rain events will increase dramatically in some parts of the country, especially in Washington, Idaho and western Montana. The bluest locations on the map will experience two or more additional days per year of record rainfall.
Pittsburgh is not exempt. We’ll see an increase in downpours and there will be an even higher frequency north and south of us. Watch out, Cleveland and West Virginia!
For Allegheny County this map is particularly scary because of our old combined sewer infrastructure (sewage + storm water) that overflows into the rivers after as little as 1/10″ of rainfall. If you visit our rivers you’ve seen the toilet paper. The situation is so bad that Allegheny County is under a 2007 EPA consent decree to fix it. We are not the only city with this problem!
Obviously, the time to fix our sewers is now and the solution has to handle more rain that we get today.
(map from Climate.gov. Click on the image to see the original map and accompanying article)
p.s. 24 March 2014: Oh no! Rain is the culprit in the deadly mudslide in Washington State last weekend: http://m.motherjones.com/blue-marble/2014/03/climate-change-mudslide-washington-weather