Posted here after summer to create an easily viewable link.
Original on Facebook, post date 3rd June 2014.
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Welcome to my Summer 2014 Forecast
I begin, as always with a caveat that long-term forecasting is horrendously difficult and can only really be produced in terms of the most-likely expected patterns.
My long-term followers will know I got my summer 2013 forecast pretty spot on – predicting a month-long heatwave in July when most other forecasters were expecting another washout. However this winter I underestimated the amount of rainfall (slightly above average was my prediction), my spring and autumn forecasts were reasonable though a long way from perfect.
The headline is for an above average summer in terms of temperatures, but also rainfall. Sunshine at least slightly above average. And the best chance of significant thunderstorms in our area for some years.
This is what I believe is the most likely outcome – it doesn’t mean a washout or a long heatwave won’t happen.
So onto my monthly breakdown.
June is most likely to see a strong area of high pressure develop to our north-east over Scandinavia, particularly in the second half of the month, when I also expect the Jetstream to be running south, bringing very wet conditions to France, for example. Both will be major factors in our weather here in Berkshire.
The first half of the month will be characterised by low pressure to our south-west, often bringing heavy showers for several days at a time. However the wind direction will be favourable for temperatures and should bring at least one very short spell of very warm/hot weather in the first half of the month – but only for 1-2 days before thundery rain arrives once more.
Assuming high pressure builds over Scandinavia as expected during the second half of the month, this should reverse the script to several warm, settled days, though morning cloud often taking a while to clear, interspersed with shorter spells of heavy showers – potentially some cracking thunderstorms, and then the pattern repeating itself.
The first half of the month will have around 10 days of rain falling, the second half around 6.
Overall I expect above-average rainfall, above-average temperatures and around average sunshine, perhaps slightly below average.
80% confident on this outcome.
July is most likely to see high pressure taking more of an influence over our weather, with both high pressure to our east, and also the Azores high nudging in from the south-west.
However, unlikely last year I do not expect any long heatwaves.
The first week of July (give or take) I believe will be sunny and hot. This then being followed by a thundery outbreak from the south which again could potentially bring some very high rainfall totals.
Once this system clears out of the way I expect fresher conditions with ridges of high pressure building from the south-west (the Azores high) – but this not being especially strong, so a few fine and fairly warm days will be interspersed with showery days, this pattern continuing for much of the month.
Overall I expect slightly above-average rainfall (though below average if we miss the early-mid month thunderstorms), slightly above average temperatures and slightly above average sunshine amounts.
65% confident on this outcome.
August has no clear signals, which is particularly unhelpful.
My suspicion is that we will see drier, sunnier weather in the first half, perhaps just touching the hot category for a while.
The second half being slightly more unsettled in terms of afternoon showers/thunderstorms developing but still some decent sunshine around.
Overall I expect above average temperatures, above average sunshine and average rainfall.
50% confident on this outcome.
So not bad at all, especially when you compare it to the summers of 2007 to 2012.
That said, things do change, and I will regularly update you on my long-term thoughts as summer goes on.
It would definitely be appreciated if you would like/share and invite friends.
Looking further ahead, and the early signs are for an unsettled September, a significant warm spell in October and back to cool and unsettled in November though turning settled but frosty towards the end.
But please take these autumn thoughts with a bigger pinch of salt than the council has left over from the winter.
Dare I mention winter?!
Last winter I said that the winter of 2014/15 would see more snow than the winter of 2013/14. Which will take one snowflake to be accurate.
My hunch is that we will see an early onset of cold weather in late November/December, but then turning milder and more unsettled as winter goes on.
Enjoy the summer.
