February 2018


Period: From February 2018      Issued on 08.02.2018 using data to the end of January 2018

Summary

The outlook for February and February to April indicates that river flows and groundwater levels across the majority of the UK are likely to be within the normal range. Groundwater levels in the south-east of England are likely to be below normal for the next one to three months, and in parts of the south-east river flows are likely to be normal to below normal for this period.

Rainfall

During January, England and Wales registered near average rainfall. Scottish rainfall was also near-average in total, but showed regional differences with above average rainfall in the southwest, and significantly below average rainfall in the northeast. Northern Ireland experienced approximately 140% of average rainfall, falling mainly in the west and principally as a result of storms “Eleanor”, “Fionn” and “Georgina”.

The Met Office 3-month Outlook issued on 26th January indicated that for February, below-average precipitation is more likely than above-average precipitation. For February-March-April as a whole, the chances of above- and below-average precipitation are close to normal. The probability that UK-average precipitation for February-March-April will fall into the driest of five equal categories is 20% and the probability that it will fall into the wettest of the five categories is between 15% and 20% (the 1981-2010 probability for each of these categories is 20%).

River flows

River flows for January were predominantly normal to above normal across much of the UK, with above normal flows focussed mainly in the west. Reflecting January’s precipitation patterns, below normal flows were recorded in some catchments of northeast Scotland, and record-breaking exceptionally high flows were recorded in two Northern Irish catchments, the Mourne and Faughan.

River flows in parts of south-eastern England are likely to be normal to below normal for both February and the February to April period. Although many river flows were above average in January, the responsiveness of these catchments to rainfall and the provision of a slightly below-average precipitation forecast, indicate that river flows are most likely to be within the normal range across the rest of the UK for February and February-March-April.

Groundwater

Although groundwater levels generally increased from their January levels, they remained below normal across most of the Chalk aquifer away from the south coast.  Elsewhere, levels were mostly in the normal range.

Groundwater levels for the Chalk of the North Downs and through the Chilterns across to Suffolk, are likely to remain below normal in February, and through February-March-April. Elsewhere, groundwater levels are likely to be within the normal range for the next one to three months, with the exception of the northern Permo-Triassic sandstones, where levels  are likely to be normal to above-normal over the February to April period.

Further information - February 2018

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