EXPERT DISCUSSION: Europe Spring & Preliminary Summer 2014 Forecast

Written by Mark Vogan on March 16, 2014 in Rest of Europe, Spring 2014, United Kingdom & Ireland with 0 Comments

[s2If current_user_can(access_s2member_level1)]

Based on current circumstances both in atmosphere, ocean and soil, it would appear that we’re going into a ‘changeable weather pattern’ for the spring. In other words, we could go back and forth between ridge and trough but the overall theme is likely to sway more towards low pressure in the means over Western Europe while a ridge holds over Eastern Europe.

Precipitation should be normal to above normal throughout late March, April and May in the West, drier than normal in the North and East.

Looking At The Past

First and foremost, I want to show you the difference in water temperatures globally between December 2, 2013 and now and past SST profile to start spring in the past few years because the past can say a lot.

Dec 2

anomnight_12_2_2013

Mar 13

anomnight_3_13_2014

Just look at how cold the North Atlantic has become. Notice the warm pool strengthened in the northeast Pacific.

Here’s the water temperatures last year at this time. Remember that the UK endured the coldest spring in 50 years followed by the warmest July since 2006.

anomnight_3_14_2013

Skip to June 3rd and note the strong warming in the north Pacific and surrounding Scandinavia. Based on DRY ground and surrounding cold waters with warmth to the north, I suspected that a mean RIDGE would develop where ground was dry and waters surrounding where cold (UK).

anomnight_6_3_2013

Here was the water temperatures at this time back in 2012. After back to back years of drought over the UK following two very cold winter’s, the skies opened with the wettest spring and summer on record. When it’s wet ground, a weak El Nino coming on and just look at that warm water surrounding the UK, you know summer will be wet!

anomnight_3_5_2012

This winter was a clear bust and I want to be clear on that. However, what’s important is knowing where I went wrong and learning from this. I can see why this winter didn’t materialise.

Reasons For Europe’s Non-Winter!

When looking back at recent past cold winters, the northeast Pacific wasn’t warm like it’s been this year and I believe that, in-part, played a role in not just the bitterly cold North America winter but helped our winter to turn out warm.

In saying that, it appears to go further than that. According to Joe D’Aleo of WeatherBELL, he made mention of the solar flux and QBO. For hemisphere-wide cold like we saw back in 2009-10 and early 2010-11, we need a LOW solar flux, Joe states that this year it was moderate with a strong westerly QBO which meant the stratospheric warming which DID OCCUR (Asia to western North America) favouring a +PNA which led to a cold eastern United States and Russia winter, strong winds blowing across the Atlantic produced a warm Europe winter. A low solar fluxes make for a low easterly and high westerly QBO which allows more blocking over the North Atlantic as well as the polar region and therefore we here in Europe see cold as well as North America. That would favour a -AO AND NAO rather than a -AO but +NAO.

Here’s a chart he showed. This year remains to the right hand side of the chart.

Source/Credit: Joe D’Aleo

Joe states that next year, an easterly QBO develops and the solar flux will drop. He’s suggesting a colder winter for us.

I focused perhaps too much on SST’s. In the back of my mind, I was aware of the moderate solar flux but ignored it. The North Atlantic tripole looked great for a cold Europe winter.

As for good seasonal forecasts, last summer can be counted, well it was my best summer forecast to date as I stated back in April last year that we could be looking at the ‘best July since 2006’. When all was said and done, it turned out to be just that! To produce future forecasts, we must understand the reasons behind certain types of pattern.

I came up with last summer’s accurate forecast based on the cold and more importantly DRY spring with laid to the very cold surrounding waters and the neutral ENSO.

Why The Record Rains Of Summer 2012

March 2012 saw record warmth over the UK and Western Europe which allowed waters to significantly warm. The record dry and warm Christmas through March period was followed by a complete turnaround with record rains occurring in April. By the end of May, wet ground + warm surrounding waters set the stage for a record wet summer and year overall.

We must consider current and projected SST’s both locally and globally. What type of ENSO index we have and are projected to have, what the current solar situation and although not the be all and end all, the trend of the NAO/AO.

Why An Expected Back And Forth Pattern This Spring And Summer?

Back to current SST’s. That’s a very cold North Atlantic with warmth in the North Sea.

anomnight_3_13_2014

Looking quickly at this chart above, you could be forgiven for thinking that another warm summer is on the way BUT, the ground is WET not dry. The North Sea and Norwegian Sea is warm, North Atlantic from Newfoundland to Ireland is cold but because of that warm and not cold North Sea along with the wet ground, suggests a different summer to last year. Another important factor to consider, EL NINO is expected to show up this summer which may ‘attribute’ to wetter conditions during the second half of summer. With a wet west and drier east of Europe, I believe the wetter conditions continue here over the UK this spring and summer while a dry and therefore warmer spring and summer is likely over Scandinavia down across central and eastern Europe.

An El Nino is a warming of the equatorial Pacific and for an official El Nino to occur, there must be a warming of at least +0.5 degrees in Nino Region 3.4 for at least 3 consecutive months.

Forecast issued last month…

Source/Credit: Storm Prediction Center

Had El Nino been coming on now and warm water completely surrounding the UK then I would be talking a downright wet spring which would lead to a wet summer but I think we will go back and forth, changeable if you will.

Based on all that’s been shown. I believe we have spells of cool and wet as well as warm and dry, evenly spread throughout this spring and summer. It’s going to be interesting seeing just how wet or indeed dry we are by the end of May. I say dry because there is an outside potential for a cooler, drier spell which may help dry things out more. If that happens, we could have somewhat more prolonged warmer spells this summer.

My hunch right is that we will remain beneath the cross roads between the trough which holds over the Atlantic and the ridge which holds over Europe. There should be a swaying back and forth which means we see spells of cooler, wetter and spells of warmer, drier both this spring as well as summer.

Here’s the Jamstec model for spring and summer temps and precip.

Spring temps