While the 2012 Arctic storm was a strong one, as Newman noted, it was not unprecedented. To confirm Newman's claim, we examined daily surface pressure maps from NCEP-NCAR and NCEP-II DOE reanalysis data. Low pressure systems are typically associated with a tight pressure gradient that results in strong surface winds.
In the 34 years between 1979 and 2012, we identified 19 deep low pressure systems (defined here as having a central pressure less than 980 hectopascals [hPa]) in the Arctic between 15 July and 15 September. Most of these deep lows occurred over the Barents, Laptev, and Kara seas, so they are not suitable analogs for the 2012 storm.
However, there were nine previous storms during this timeframe in the same general area as the 2012 event. Of these, we identified five best analogs for the 2012 event. These occurred in 1980, 1990, 1991, 1994, and 1997 (Figure 3 - click for a larger version).
Figure 3: NCEP/NCAR sea level pressure maps in (from right to left and top to bottom) on 07 August 2012, 28 August 1980, 12 September 1990, 06 August 1991, 17 August 1994, and 03 September 1997.
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