From months to minutes – exploring the value of high‐resolution rainfall observation and prediction during the UK winter storms of 2013/2014

Abstract

ABSTRACT:As the societal impacts of hazardous weather and other environmental pressures grow, the need for integrated predictions that can represent the numerous feedbacks and linkages between sub-systems is greater than ever. This was well illustrated during winter 2013/2014 when a prolonged series of deep Atlantic depressions over a 3 month period resulted in damaging wind storms and exceptional rainfall accumulations. The impact on livelihoods and property from the resulting coastal surge and river and surface flooding was substantial. This study reviews the observational and modelling toolkit available to operational meteorologists during this period, which focusses on precipitation forecasting months, weeks, days and hours ahead of time. The routine availability of high-resolution (km scale) deterministic and ensemble rainfall predictions for short-range weather forecasting as well as weather-resolving seasonal prediction capability represent notable landmarks that have resulted from significant progress in research and development over the past decade. Latest results demonstrated that the suite of global and high-resolution UK numerical weather prediction models provided excellent guidance during this period, supported by high-resolution observations networks, such as weather radar, which proved resilient in difficult conditions. The specific challenges for demonstrating this performance for high-resolution precipitation forecasts are discussed. Despite their good operational performance, there remains a need to further develop the capability and skill of these tools to fully meet user needs and to increase the value that they deliver. These challenges are discussed, notably to accelerate the progress towards understanding the value that might be delivered through more integrated environmental prediction.

The UKC2 regional coupled environmental prediction system

“…Non-linear wave-wave "quadruplet interactions", which shift wave energy toward lower frequencies, are parameterized using discrete interaction approximation (Hasselmann et al, 1985). Wave energy propagation uses a second-order upstream non-oscillatory scheme (Li, 2008) with "garden sprinkler effect" alleviation following the averaging scheme proposed by Tolman (2002). A series of compilation switches, described in Table C7, are applied in building the WAVEWATCH III executable for UKW2 and UKC2.…”

“…While mature national-scale operational forecasting capability on timescales of hours to days, such as delivered by the Met Office in the UK (e.g. Lewis et al, 2015), typically includes simulations of the atmosphere and land surface, hydrology, ocean, waves and other environmental components, these forecast systems tend to be developed and run in relative isolation, with limited information sometimes exchanged between systems by file input through initial conditions or forcing data. Recent advances in the skill, resolution and information content (e.g.…”

Development and verification of a real-time stochastic precipitation nowcasting system for urban hydrology in Belgium

“…However, the conclusions of the previous studies are strongly affected by the limited number of flood events analyzed. An extensive review of the usage of precipitation forecast systems for operational hydrological predictions in the UK from very short to long ranges (including STEPS) is provided in Lewis et al (2015).…”

Correcting for wind drift in high resolution radar rainfall products: a feasibility study

“…The winter of 2013-14 brought a succession of low pressure systems across the UK, with strong winds and thunderstorms resulting in significant flooding and damage to infrastructure (Lewis et al, 2015). Whilst extreme, this weather provided a good set of cases on which to assess the potential of wind drift correction in a flood forecasting context.…”