A Look Back At A Successful Summer 2015, September Off To An Extreme Start

Written by Mark Vogan on September 6, 2015 in Autumn 2015, Rest of Europe, Summer 2015, United Kingdom & Ireland with 0 Comments

Long range forecasting is often seen to be impossible and laughed at. However it’s predictable if you know what your looking for. Some years I struggle and get it wrong, other years like 2015, I get it right. The lessons learned from 2012 have certainly paid off this year.

Right or wrong, here you get the reasoning, explanation and evidence to back up my forecasts.

September has gotten off to an extreme start on both ends of the temperature ledger. We’ve commenced autumn with a very stuck, blocky and highly amplified pattern.

A persistent high just west of the UK and low pressure over Denmark has supported two seasons over Europe with persistent northerly winds making for a cold start to September across all of West Europe while east of that Danish record heat and been breaking records across Central and East Europe.

Credit: M Ventrice

This follows a colder and for parts of the UK, a wetter than normal summer as forecast but it was one of the warmest and driest for central and eastern Europe!

Credit: Simon Cardy

I’ve said right from the start of the year that the cold North Atlantic will be the sole driver in this years temperature departures over Europe. As expected, warm spells were short lived and dwarfed by lengthy spells of cool, wet and windy.

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The below chart representing a 1 year change in SST’s says it all. Note the dramatic cooling over the northeast Atlantic verses the dramatic warming in the central Mediterranean. This has had major influence on pressure heights and air temperature above.

Credit: Simon Cardy

Rainfall has been primarily down to the El Nino as I’m pretty sure that if there was no El Nino, this summer may well have been drier than normal due to the cold waters.

Look at the Jan-Aug 2m temp anomaly. Says it all doesn’t it.

Credit: Simon Cardy

Best UK-wide weather since April?

Now that the high is finally building over the UK, winds are lighter but as a result nights are cooler. These were the lows this morning.

Credit: Met Desk

With clearer sky and lighter wind tonight, it may be even cooler Sunday night into Monday with a few spots sheltered spots dipping below freezing.

Credit: Tropical Tidbits

Even rural France could see widespread low single figures tonight.

We open the upcoming work week with northerly winds and a distinct autumnal feel but by week’s end, winds will blow from the south and so expect a more summer-like feel once again.

It’s all about the positioning of these blocking highs.

Credit: Tropical Tidbits

Friday 11th

Credit: Tropical Tidbits

Expect a break down next weekend into the start of the following week but I anticipate the return of high pressure through the last 10 days of the month.