Rest of summer – Another cold one?
The remainder of summer is likely to remain largely unsettled due to the jet stream being pushed much further south than normal. This displacement of the jet stream allows unseasonably cool and very wet weather to dominate the scene over much of the country. This dominant pattern is also why the country experienced a record-breaking cold and wet summer during last year (as forecast in January 2011), when all three months of summer came in at below-average in terms of temperature. This is in part due to the continued low levels of solar activity and how it also intrinsically alters major factors such as cloud coverage. Weak solar activity is also influential on predominantly negative phases of the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO).
There is the potential for a possible shift in this pattern as we progress throughout August and into September, which could result in some warm or very warm periods of weather at times within these months (forecasting confidence is medium range). However, if a pattern shift does not occur throughout the final summer month of August, then we will be facing a summer of similar magnitude to last year in terms of temperature or colder.
This is also why I stated in my original summer forecast in February “I also don't want to go as far as saying that the summer will be as cold as last year, but I also don't want to rule out a similar scenario unfolding either.”