The Quasi Biennial Oscillation (QBO) for June 2018 was -28.45 and was the most negative (easterly) month since February 2015. Since QBO records began in 1948, this figure for June 2018 was also a record breaker of negative QBO for the month of June. I thought it'd be fun to look at previous Junes with a QBO of -20 or less and the Winters that followed for the sixth analogue of Winter 2018-19.
The 500mb height anomaly reanalysis of these Winters that followed on from the very negative QBO Junes shows a vigorous block of high pressure over top of Greenland and ridging back into Siberia. There is an area of below average heights over the Bay of Biscay. The way the blocking is aligned forces an easterly wind direction to take place and it looks like a very cold reanalysis. It doesn't look "very snowy" so to speak because of the trough being as far south as it is but there would be some snowy episodes through the Winter season if this were to come off just because the blocking is so intense. It wouldn't take much adjustments though for this to turn into a snow fest of a reanalysis.
I was quite frankly surprised with this reanalysis because many of the Winters in the reanalysis don't seem particularly amazing to me when I first glanced at them. The only real snowy ones I can see are 2012-13, 2010-11 and 1977-78. Nevertheless, the overall reanalysis does look quite cold.
