There are headlines in the media today suggesting the UK is in for a “hotter than usual summer”. This prediction seems to have been based on the latest Met Office three month outlook for contingency planners.
As we’ve discussed previously, the outlook is not a normal weather forecast. It’s an experimental and complex outlook based on probabilities and is designed specifically for those who plan ahead for various contingencies based on possible likelihoods. It assesses the likelihood of five different scenarios for both temperature and rainfall for the whole of the UK for the next three months, based on the more probable prevailing weather patterns.
It’s a bit like the science-equivalent of factoring the odds on a horse race and like any horse race; it’s always possible the favourite won’t win.
This is why the outlook has to be used in the right context. So it’s useful for contingency planners, but not that useful when you want to know, for example, which summer weekend looks good for an outdoor event.
What does the current outlook say?
The current forecast does not cover all the summer months (June, July, August), it is for May, June and July, and for this period long-range prediction systems only weakly favour certain types of weather patterns above others. Therefore the outlook suggests the chances of above – or below – average rainfall are approximately similar, while there is only a slight increased risk of warmer than average conditions.
However, there are still substantial probabilities that either average or cool/dry conditions may occur. This is because there are many competing factors that determine what our weather will be like in the coming months.
For May-June-July as a whole, the Met Office seasonal prediction system, along with systems from other forecast centres, show an increased probability of lower-than-average pressure to the north of the UK and higher-than-average to the south. Despite this, and the seemingly good agreement between seasonal predictions systems, the signal is only small, so the chances of above- and below-average temperatures are approximately similar. There is also a suggestion of an increased chance of wetter-than-average conditions, but this shift is small and we expect the likelihood of weather-related risks to be close to normal during this period.
If you want to plan up and coming activities head to our forecasts pages for a detailed 7 day forecast or a 30 day look ahead at weather trends.
Official blog of the Met Office news team 
Reblogged this on WeatherAction News.
The main culprit in saying the Met Office expect a ‘red hot’ summer was I believe the Daily Express.
It is now the 23rd June and last night saw a months rain in just over an hour in places. Houses were flooded in Romford. I notice that the front gardens in those streets were mostly concreted over and plants removed, so no wonder. What a shame people still don’t understand the role plants play in removing ground water.!!
Anyway. Latest long range forecast sees no prolonged hot or dry weather before mid July. The jetstream will remain south of us for that whole period. That leaves two weeks in July? What are the chances? Very slim.
In my definition, a hot August is one with aprox half the days above 25c in the London region. Before 2003, there were regular hot Augusts of between 13 to 18 hot days, and gaps of between 1 to 5 years between those years. Since 2003 there has not been one year that has had more than 9 hot day (even though average temps are rising). So the chances are very very slim indeed for anything other than a mediocre summer now.