Wednesday, February 15, 2012

State Climatologist on NJ Weather

Today's post explores some factors influencing Princeton's weather. Recaps of 2011's extreme weather, in the Trenton Times and also on a CBS program called "Eye on the Storm", featured interviews with New Jersey's state climatologist, who turns out to be a Rutgers professor by the name of David Robinson. He's been state climatologist for 20 years. In the two interviews below, he describes the various influences that contributed to the extreme weather of 2011. I summarize each interview.


For the past two winters, NJ weather has been influenced by a "la nina" event, which has to do with below average temperatures in the eastern tropical Pacific. Usually this means more mild winters and somewhat less snow than average, but there's another phenomenon called the North Atlantic oscillation that can trump the effect of "la nina". That's what happened last winter, when the North Atlantic oscillation "tanked", i.e. went into a negative phase that dumped snow on central and northern NJ from Christmas through Groundhog Day.

Because NJ is "squeezed in" between a huge continent to the west and the ocean to the east, and is situated halfway between the tropics and the poles, extended forecasts are particularly difficult. In terms of extreme weather, 2011's 18 inch rainfall in August in NJ shattered the previous precipitation record of 12 inches in Oct, 2005.

http://watch.njtvonline.org/video/2181587719/

Weather records for NJ extend back to 1895. 2011 was unprecedented in a number of ways, with the wettest month ever recorded, the wettest summer on record, and a snow storm like no other ever recorded in October. One can't take any one storm or any one year and say it's due to changing climate, but we have to look at human impact on the globe. Because the globe has warmed, we have a more energized atmosphere that can hold more moisture. Not every year will be worse than the last, but we may be coming to a new normal with warmer weather over all and more flooding rains and odd extreme weather events. 



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