September 2016


Period: From September 2016      Issued on 09.09.2016 using data to the end of August 2016

Summary

The outlook for September is for river flows to be within the normal range for the majority of the UK, with normal to above normal flows in central southern England. Flows in north western England are likely to be normal to above normal over the next three months. In the northern Permo-Triassic sandstone aquifers, groundwater levels are likely to remain above normal to exceptionally high throughout September, whilst levels across the rest of the UK are likely to be normal to above normal for the next three months.

Rainfall

Rainfall across the UK for August was varied. Below average precipitation fell on southern England, Northern Ireland, south-western Scotland and eastern Scotland. The majority of northern England had above average rainfall, particularly in the north-west. North-western Scotland also received above average rainfall.

For September, the forecast for UK precipitation suggests that the chances of above and below average rainfall are fairly balanced. For September-October-November as a whole, above average precipitation is considered slightly more probable than below average. The probability that UK precipitation for September-October-November will fall into the driest of five categories is between 15 and 20% and the probability that it will fall into the wettest of five categories is around 25% (the 1981-2010 probability for each of these categories is 20%).

River flows

River flows for August mostly decreased from their July levels and were predominantly normal to above normal across the UK.

The outlook for September indicates that flows over most of the UK are likely to be within the normal range. Flows in central southern England are likely to be normal to above normal over the next month, and flows in north western England are likely to remain normal to above normal over the next three months.

Groundwater

Groundwater levels in August remained normal to above normal across the UK, with above normal to exceptionally high levels persisting in parts of the northern Permo-Triassic Sandstone. 

The outlook for September-October-November indicates that groundwater levels across the UK are likely to continue to be normal to above normal, with the exception of the northern Permo-Triassic sandstone aquifer, where above normal to exceptionally high levels are likely to persist throughout September.

Further information - September 2016

Comprehensive further information that supports the production of the Hydrological Outlook UK is available here.