A week or two ago the media was full of stories of an exceptional heat wave that would take temperatures to new records. We were told that we should expect drought and intense heat. A few days on and temperatures slumped, with plenty of rain over the weekend. There has been little news reporting of the change of weather, and no pieces apologising for getting the forecasts wrong about new records by last week end. If as expected temperatures pick up again and there is no more rain we might hear about that.
I thought at the time of the forecasts that the weather was more like the weather in dry hot summers I remember in the past, so I looked up some of the figures. According to the Met Office 30 year numbers the average summer temperature has been 14.3 C and the average rainfall 241 mm. Every summer in the last ten years save 2013 has been wetter than the 30 year average, with 2011, 2012 and 2015 cooler than the average. 1976 was clearly much drier and hotter than recent years, as were some summers prior to that.
After the recent hot spell the highest temperature records for 1976, 42 years ago, remain intact. 2003 also recorded a high temperature for Faversham in 2003 which some say was slightly higher than 1976 for England.
Many things influence the weather, making it difficult to come up with a reliable model which accurately predicts what might happen next. Wind speed and direction changes, water vapour content in the air alters, cloud cover is very variable, solar activity alters in intensity, the jet stream moves around. Short term weather forecasting has got better because the experts have greater visibility of clouds on their way to us, and can calculate from wind speed and direction what is likely to happen. As any sailor can tell you, however, the wind is very variable minute by minute. altering the course and pace of clouds across our landscape. It is even more difficult making a long term forecast when the clouds which will dictate so much have yet to be formed.