Circulation
October 2020 – circulation
It’s no big surprise why October 2020 was so wet across IONA when you look at the MSLP anomalies across the northwest of Europe. MSLP was lower than average by 5.6 hPa across the North Sea, …
Rise in pressure of 63.7 hPa in just 66 hours at Stornoway
There might be another SYNOP station with a slightly larger rise in pressure than the one at Stornoway, but the steady rise of 63.7 hPa in just 66 hours from a low of 966.6 hPa at …
Rise in pressure of 63.7 hPa in just 66 hours at Stornoway Read More »
Change of type signalled for early November
A change of type is coming hard on the heels of a string of fierce extratropical lows that ushers in the start of November, that’s if the latest forecasts from the models are to believed. The …
Why has October 2020 been so cold?
Why has October 2020 been so cold up until now? The reason why temperature anomalies have been three degrees below average across central France is that mean pressure during the month has maintained a low pressure …
Recent circulation indices
An abrupt start to autumn 2020 is evident in these six charts of various objective LWT circulation indices since the 7th of July 2020. Mean pressure has been falling away since the second week in September, …
A change of type by mid-week?
A change of circulation type is underway during the coming week, that’s according to the latest NWP forecast from the ECMWF hires model, and by mid week high pressure will dominate across the north of the …
A taste of what’s to come this Autumn?
The one thing that you can never say about the weather across IONA is that it’s ever boring. After an eight day heat wave across England comes to a thundery end, a taste of maybe what’s …
July 2020 – circulation
You don’t have to look too far to find the reasons for the cold July across IONA and the northwest of Europe. A squeeze of westerly winds between lower than average pressure across Scandinavia and the …
July 2020 – North Atlantic mean temperature anomalies
A cool July across most of the North Atlantic and northwest Europe come to that. Above average temperatures seem to have been pushed back to the continents of Africa, central Asia and North America. It may …
July 2020 – North Atlantic mean temperature anomalies Read More »
Sixth most cyclonic June since 1871
I hadn’t realise until I ran the analysis on the objective LWT data from the CRU just how cyclonic June 2020 had been. It’s the joint sixth most cyclonic June in LWT circulation types since 1871, …
June 2020 – circulation
There is an in interesting belt of low pressure that stretches from southern Greenland southeast for around 8,000 kilometres to the Gulf of Oman this June. The part of the belt that lies over the Atlantic …
Heatwave air mass (updated)
“We quite often see warm southerly air from the continent bringing these high temperatures to the UK in summer, however this week the air across the UK has arrived from the Atlantic. This Atlantic air will …
Mid June report
The first thing I can say about the circulation in the first half of June 2020 is that if it had been a January it would have been one hell of a cold and snowy one, …
May 2020 – circulation
It’s easy to see why May 2020 was so sunny and dry and relatively warm, with anomalies of 6 hPa across central England May’s like this don’t come along that often at all.
So high pressure is in charge is it? The proverbial fly in the ointment
It is rather uncommon to see a spell of moderate rain with pressure over 1030 hPa but it’s forecast to happen overnight across northern Scotland. There seems to be no end to these kind of scenarios …
So high pressure is in charge is it? The proverbial fly in the ointment Read More »
The recent record mild winter in Europe
How much of the underlying cause of the recent record mild winter across Europe and western Russia was purely down to the dynamics of atmospheric circulation and how much of it due to climate change brought …
DIY North Atlantic Oscillation
I thought I would try and add some extra functionality to my MSLP reanalysis application to allow me create my own DIY North Atlantic Oscillation series. It’s the simplest of approaches to NAO that I could …
High Nikolas hangs on in north
The high pressure that BIM have named Nikolas is set to stick around this week and after it’s done a quick pirouette further south, its forecast by the midnight run of the hires ECMWF model to …
March 2020 – circulation
The mean pressure chart for March 2020 has calmed down considerably on previous months. Large positive anomalies (+7hPa) across the Azores beefed up the resident Azores high, whilst there were very large negative anomalies, far to …
Retrospective on winter 2019-20
Here are a dozen charts of ten day mean pressure for Europe and the North Atlantic during this last winter of 2019-20. It’s easy to see why the winter was such a mild affair across much …
…out like a lamb
March 2020 did start off windy enough, coming in rather lion like with the remains of storm Jorge the French and Spanish named, even though it was probably a lot windier here in the UK than …
High Keywan set for a long stay
It looks like high Keywan, as the BIM have named it, will stick around in the central Atlantic right out till day ten if this ECMWF hi-res forecast proves correct. It’s forecast to be as intense …
Another 1050+ high
It will be interesting to see if the above forecast from the ECMWF plays out and we do seen an intense high of over 1050 hPa becoming established to the west of Scotland by the weekend. …