EUROPE: +NAO Could Be Coming Back To Haunt As Spring Approaches

Written by Mark Vogan on February 13, 2015 in Rest of Europe, Spring 2015, United Kingdom & Ireland, Winter 2014/15 with 0 Comments

2 weeks ago while the UK did a little shivering, so Greenland was balmy under a blocking high. Now that the blocking high is over Europe, so Greenland shivers beneath the strongest cold pool/trough of winter and the UK enjoys relative warmth.

Temps took a dip to -62C or -80F this AM at Greenland’s Summit Camp research station.

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The NAO is firmly positive and really hasn’t been out of positive mode all winter.

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However, as we enter late winter and seasonal feedback shifts as the sun climbs higher in the sky, I am struggling to see much winter here over the next 15 days. THAT DOESN’T MEAN WINTER’S OVER.

Despite the +NAO, other drivers including the east QBO, weak El Nino, SST profile and solar downturn have still brought cold air masses along with snow to the UK and West of Europe.

My concern before winter was always that the solar wasn’t going to be low enough to true cooling influence. I believe the lack of negative NAO/AO is down to solar.

Expect more negative in the coming winters as we head back towards a solar min. While I remain with the idea that cold will come back, those other, overwhelming drivers which brought cold to our shores this winter, may have less influence into March.

You want more negative NAO during winter end games and I don’t see it as of now anyway. Stronger sun and positive NAO typically leads to more ridging and warmth over the NE Atlantic and Northwest Europe.

We saw an extreme example of this back in March 2012 when a strong +NAO with an El Nino, brought a record warm March. Notice in the below 500mb height anomaly charts that despite the return of Atlantic lows this upcoming weekend, a stronger than expected Azores ridge develops, forcing a more northerly storm track. Unless we burst that Azores bubble, I’m afraid the cold that these lows transport, won’t cross the UK. We will largely remain in the mild SW flow. 0-7 day MEAN 500mb height anomaly off ECMWF