This blog post is going to be about the seventh analogue I have picked for Autumn 2018 and it is on Autumns that followed on from "backloaded Springs". If you do not know what this means, it means Spring gets progressively warmer and drier after a very wet and or cool start. Spring 2018 was exactly this, March was one of the wettest on record and the coldest since 2013. April was very wet for many too but became much warmer than March whilst May was a very warm, dry and sunny month. A perfect textbook example of a backloaded Spring.
The 500mb height anomaly reanalysis for these Autumns shows very deep areas of below average heights over the Arctic Circle and down into the east of the UK with a mid-Atlantic ridge. This forces the winds to be from a northwesterly direction which in Autumn would be relatively cool but not exceptionally so. Temperatures would be rather below average but it'd be an unsettled Autumn due to how close the below average heights are to the UK and Ireland.
The Septembers aren't much different to the above reanalysis but the below average heights are over top of us than to the north or east of us meaning very unsettled and due to the wind direction coming from a northwesterly, cool month.
The Octobers look cold and blocked. Stubborn mid-Atlantic ridge up to Iceland with the winds coming from a northeasterly. The trough is a bit far for good snow potential and thus it seems more settled especially out to the north and west of the UK and much of Ireland. It's similar to October 2010 though funnily enough, 2010 is not in the analogue.
The Novembers look very unsettled and relatively cool with again northwesterly being the main wind direction due to how the heights are aligned.
It'd be a fairly wet and cool Autumn overall. The deep trough of below average heights over Scandinavia in each of the months looks quite strange seeing how 2018 has fared that I don't think this is an especially good analogue to fit with the current scenario. Couple more analogues and we'll be looking at years that have appeared the most in the Autumn 2018 analogues (so far) which will give us an indication of the trends overall of these analogues for the Autumn 2018 forecast.
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