Big High Aloft: the North Pole Edition

Here is the 4am ADT Friday 500 mb analysis by Environment Canada. See that huge 585 dm high near 85N/170W? My friend and former colleague Stu Ostro has done some work with the NCEP reanalysis data (1948-2011), and finds that this is close to the highest 500 mb height of record in the 85-90N belt (exactly where it ranks will depend on how the numbers shake out in the reanalysis). What this translate to is that, as a first approximation, underneath the high, the average temperature in the airmass between the surface and 500 mb (about 18000 feet) is about as warm as it has been anytime in the past 63 years.

Update: according to the NCEP reanalysis, on Thursday Jul 07 the mean 500 mb height 85-90N was 5877 gpm. This breaks the previous record daily average of 5848 gpm set in July 1966