This video captures the day after the actual summer solstice.
Well, we've passed the point of mid winter, and day light is slowly increasing... So the long range freak in me is naturally starting to think ahead to spring, and what will it bring?
Will we get a March like 2012, and an April like 2007 (or 2015), followed by a hot and thundery May? Or will we get that taste of winter like March 2013, and April 2016? Or will it be a season of many weathers?
What would you like Spring 2017 to bring to us here in the UK?
Personally I'd like to see traditional month of March, a month of many weathers, ranging from snow, with strong squally winds, to that first nice seasonal burst of spring warmth, but with cool nights, and an occasional foggy start.
As for April, I'm all in favour of some squally showers, before slowly giving way to pleasant sunny days.
And finally, the month of May, this is the time when I like to see the first true burst of summer heat, so I can get the barbecue out accompanied by a good old thundery breakdown
So what are everyone else's thoughts, hopes and wishes for spring 2017?
PS. Mods, if I've put this in the wrong place, or I'm too early, then feel free to move or delete as required.
We're now into meteorological Summer (you'd never know it today) but here's how May ended up here.
High: 23.7 °C - [May 12th]
Low: 0.2 °C - [May 1st]
Avg: 13.2 °C
MetO Regional Avg: 11.2 °C
High: 97 %
Low: 32 %
High: 1029.5 hPa - [May 1st]
Low: 1004.7 hPa - [May 12th]
Max Gust: 24 mph - [May 21st]
Max Speed (10 Min Avg): 10 mph - [May 21st]
Avg Speed: 3 mph
Month: 74.6 mm
MetO Regional Avg: 77.2 mm
High Rain Rate: 39.8 mm/hr - [May 18th]
High Daily Rain: 16.4 mm - [May 21st]
High Hourly Rain: 7 mm - [May 18th]
Solar & Sunshine:
Max Daily High Solar: 1245 W/m² - [May 1st]
Min Daily High Solar: 436 W/m² - [May 2nd]
Max Sunshine: 12 hrs - [May 4th]
Min Sunshine: 0 hrs - [May 21st]
Total Sunshine: 157.8 hrs
MetO Regional Avg: 194.5hrs
More details can be seen here:
A wintry spell in late April - not exactly what one would expect! Many places in Western Europe have experienced wintry temperatures and even snowfall, for instance in the Netherlands people could greet a wintry landscape with snow actually settling! This caused quite some traffic jams and accidents on the road.
Snowy landscape in the Netherlands on the 24th of April. Source: Weeronline.
Snow did not only reach the Netherlands, but also in low-lying areas of Switzerland some snow fell, although only somewhat higher up the landscape got a wintry white colour.
Slide of Arctic air
The main culprit of the snow can be traced down to a slide of Arctic air which has come all the way down from areas near the North Pole. Fuelled by the relatively mild waters of the North Sea, this air becomes unstable and a lot of showers and small-scale low pressure areas spin up. Couple this with the unseasonably low temperatures and the snow is there!
Slide of cold Arctic air envisaged by a satellite image as of 25-04 18Z. Source: Eumetrain.
The image above nicely shows the cold air reaching all the way down into Western Europe. The red colours denote polar/arctic air which is flooding down over Europe from the north. Interestingly, though, this setup has been present for a number of days. This raises the question as to what is causing this persistent northerly airflow.
A real traffic jam in the atmospere
For the solution we look at a more global picture of the Northern Hemisphere in the midtroposphere. And that is not a usual one to say the least.
Pressure at 500 hPa and anomalies (colours) as of Monday 18Z. Source: Tropicaltidbits.
The most clear feature that shows up here is very strong ridging (high pressure) at 500 hPa which extends all the way towards Greenland. This is a nice example of a block which has been present for quite some time now. This feature is what is kind of causing the atmosphere to be 'locked'; pressure systems do not move at all or barely in a couple of weeks. Think of it as a traffic jam in the atmosphere.
The counterpart of the high pressure area is located over Mid-Europe, which shows itself as a persistent trough even reaching Africa. This feature is partially responsible for the cold temperatures aloft and thereby a generation of a lot of showers. But this is not where the story ends.
The same image, but now with airflow direction indicated in white. Source: Tropicaltidbits.
The key for the cold air at low levels (and also partially at upper levels) is that between the high pressure area near Greenland, and low pressure over Scandinavia and Central-Europe, there is a deep northerly flow which starts off near Greenland and flows down all the way towards Tunesia.
More cold to come?
WIll the pressure situation remain locked, and will we continue to experience a brisk northerly airflow? The high pressure area near Greenland appears to be pulling away towards Russia, but this would still cause the cold to remain entrenched over Europe with also more unsettled weather to come. So one thing is for sure: the cold is going to stay around for some time still. Impressive for April to say the least! If we would only have had this in winter...
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