August 2015


Period: From August 2015      Issued on 11.08.2015 using data to the end of July 2015

Summary

The outlook for August is for normal to below normal flows across England and Wales, with an increased likelihood of below normal flows in some groundwater-fed catchments of southern and eastern England. For England and Wales, the outlook for the next three months is similar to that for August The outlook for Scotland is uncertain in the coming months but normal to above normal flows are most likely in the south and east and normal to below normal flows in the north. Groundwater levels are likely to be normal to below normal in August throughout the UK. Over the next three months in parts of southern and eastern England below normal levels are most likely.

Rainfall

The latest predictions for UK precipitation favour below-average rainfall for August and August-September-October as a whole. The probability that UK precipitation for August-September-October will fall into the driest of our five categories is around 30% and the probability that it will fall into the wettest of our five categories is 15% (the 1981-2010 probability for each of these categories is 20%).

River flows

River flows in July reflected the varied pattern of rainfall. Parts of Scotland experienced some notably high river flows in response to rainfall more than double the average for the time of year. For England and Wales flows were below normal in parts of southern and central England but generally in the normal range elsewhere. The outlook for August is for normal to below normal flows to continue for most of England and Wales, with below normal flows very likely in groundwater-fed catchments in the headwaters of the Thames, and in Wessex and Lincolnshire. The outlook for the next three months in England and Wales is for this pattern to continue. For Scotland and Northern Ireland, the outlook for August and beyond is unclear; indications are for normal to above normal flows in the south and east, and normal to below normal flows in the north.

Groundwater

In southern and eastern England, July groundwater levels were normal to below normal, notably so in parts of the Chalk in Hampshire, Wiltshire and Yorkshire. Conversely, levels were exceptionally high in parts of the slowly responding Permo-Triassic sandstones of the Midlands and southern Scotland. The outlook for August is for the continuation of a similar pattern. Below normal levels are likely in Wessex, Wales and eastern England, whilst above normal levels are likely to persist in parts of the Permo-Triassic aquifers. The outlook for the next three months is also similar, with exceptionally low levels possible in parts of the southern Chalk.

Further information - August 2015

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