The Jersey Downpours - An Update

A couple days ago, I wrote about the absence of evidence that "heavy downpours are really increasing dramatically" in the most populated regions of New Jersey.  Of course, the impetus for this discussion is that climate change impacts are widely used to justify increased public infrastructure spending.  As has been widely discussed at AT and elsewhere, such climate-related justifications are often not supported by the climate data itself.

Some climate activists were concerned that my article appeared to consider only the city of Newark and thus was not representative for the bulk of New Jersey's population.  These types of concerns are unwarranted.

First off, NOAA's National Weather Service database provides what are termed “areas” of data that are representative of a region.  Thus, the “Newark Area” data is broadly indicative of the area in and around Newark, which is where the majority of the state's population resides.

Of equal importance, the climate activists may be interested to know just how poor the climate record is for most of New Jersey.  The following table shows the individual NOAA-NWS climate sites and their corresponding trends – or absence of significant trends – in the number of days each year having 1, 1.5, or 2 inches or more of precipitation since 1970.

Only six of the 19 stations have sufficiently complete climate records since 1970 on which to conduct reliable trend analyses.  And of these six stations, only one (Atlantic City International Airport) has significant increasing trends in what we would consider days with heavy precipitation.  But only a very small proportion of New Jersey's residents live in and around Atlantic City.

Consequently, this suite of climate data provides no evidence that “heavy downpours are really increasing dramatically” throughout New Jersey.  More to the point: New Jersey's climate data is terribly inconsistent over the past few decades, and thus it is not clear how anyone could unequivocally conclude that “heavy downpours are really increasing dramatically” throughout the state.