October 2016


Period: From October 2016      Issued on 11.10.2016 using data to the end of September 2016

Summary

The outlook for October is for river flows to be within the normal range for the majority of the UK; the exception is for Wales where flows are likely to be normal to above normal. Over the three month period to December 2016, river flows are likely to be normal with the exception of the eastern side of Scotland and north east England where flows are likely to be normal to below normal. Groundwater levels are most likely to be normal except for aquifers around the border between England and Scotland where levels are likely to remain above normal.

Rainfall

The majority of the UK had below average rainfall in September, with very low rainfall in the extreme south east of England, the Yorkshire coast and eastern Scotland. Above average rainfall was observed in the tip of Cornwall, west Wales, Cumbria and central/western parts of Scotland.

The rainfall outlook for October (released by the Met Office on 23rd September 2016) is that the chance of seeing above-average precipitation is greater than the chance of seeing below-average precipitation. For the period October-November-December as a whole, there are equal chances of above-average and-below-average precipitation. The probability that UK precipitation for October-November-December as a whole will fall into the driest of our five categories is 20% and the probability that it will fall into the wettest of our five categories is also 20% (the 1981-2010 probability for each of these categories is 20%).

Observed rainfall in early October has been very low across the UK.

River flows

River flows for September were predominantly in the normal range across the UK. There were isolated above normal flows in south Wales and west Cornwall, and below normal flows in smaller catchments draining to the north and east of Scotland and the north east of England.

The outlook for October is for flows across most of the UK to be within the normal range. The exception is for Wales where normal to above normal flows are expected. Over the coming three months normal flows are most likely except in eastern Scotland and north east England where normal to below flows are likely. Should the current spell of dry weather continue this area in which below normal flows are possible may extend further down the east coast of England.

Groundwater

Groundwater levels in September were generally normal in an area south of a line joining the Bristol Channel and the Humber. Elsewhere levels were generally above normal, exceptionally so in aquifers around the border between England and Scotland.

The current situation is likely to continue into October and for the coming three months.

Further information - October 2016

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