Corporate report

Flood Forecasting Centre annual review 2020 to 2021

Published 9 May 2022

Applies to England and Wales

This review provides a look back at the year 2020 to 2021 for the Flood Forecasting Centre (FFC).

The period saw flood impacts from thunderstorms and multiple named storms. This meant a busy time operationally for the FFC. It highlighted the role the FFC plays in flood resilience and response across England and Wales.

1. Overview for 2020 to 2021

The main features of the year were:

• spring was a quiet time for operational flood forecasting, as has frequently been the case over the last decade
• summer thunderstorms were the main driver for flooding from June into September with surface water flooding and localised river flooding distributed across England and Wales
• the most severe storms occurred in mid-August
• from October to February, the main driver for flood impacts was Atlantic weather systems bringing more prolonged rain and a number of named storms
• storms Alex and Aiden at either end of October brought strong winds and heavy rain, resulting in some significant river and surface water flooding impacts
• a wet period before Christmas brought significant river and surface water flooding impacts to parts of the Midlands and the east of England
• storm Bella brought further rain and flooding to prolong the impacts in these areas just after Christmas
• the wet theme continued in January 2021, and Storm Christoph (mid-month) resulted in significant river and surface water flooding impacts across parts of Cheshire and Greater Manchester
• storm Christoph also resulted in flood impacts across parts of central and the east of England from river drainage in subsequent days
• further weather systems in February brought more rain generally, but especially across south Wales and south-west England, although only minor flood impacts were recorded

The table shows the highest forecast flood risk from all flood sources for any FGS issued for each calendar day for 2020 to 2021.

Month 2020/21	Green	Yellow	Amber	Red
April	29	1	0	0
May	31	0	0	0
June	17	13	0	0
July	30	1	0	0
August	15	15	1	0
September	17	13	0	0
October	19	10	2	0
November	20	10	0	0
December	15	10	6	0
January	14	12	5	0
February	5	20	3	0
March	30	1	0	0

Maps showing the observed flood impact frequency by flood source for England and Wales are available on request from ffcenquiries@environment-agency.gov.uk.

2. Main flood events

2.1 Breakdown of the summer 2020 heatwave, 12 to 17 August

The busiest operational period of the summer was 12 to 17 August, with the breakdown of the 2020 summer heatwave.

In summary:

• we forecast significant impacts from intense thunderstorms throughout the period from 12 to 17 August and severe impacts on occasion
• minor impacts were recorded widely across central and southern England through this period
• significant impacts were recorded from 15 to 17 August with widespread travel disruption across parts of the Midlands and south-east England, including central London
• the new record daily rainfall total for August of 239.9 mm was recorded in a rural part of Norfolk - however, there were only limited impacts from the most intense rain

2.2 Storm Christoph, 18 to 20 January 2021

At the start of 2020 there was already a heightened flood risk. The ground was saturated following the previous flood events over the Christmas period. Further heavy rain combined with snow melt in mid-January.

This served to prime catchments for a period of significant and widespread river and surface water flooding due to Storm Christoph.

In summary:

• exceptionally wet weather was recorded in North Wales and northern England from 18 to 20 January
• 100 mm of rain or more fell across upland areas
• parts of Cheshire, Greater Manchester and Lancashire received around the January whole-month long-term average rainfall from this event
• for north-west England and North Wales this was one of the wettest 3-day periods on record
• strong winds were recorded, particularly across eastern England and Scotland
• as the storm cleared eastwards, it brought some significant snowfalls with blizzard conditions across upland in the north-east
• for parts of north-west England and north Wales this was one of the wettest 3 day periods on record
• a significant number of properties flooded across Cheshire and Greater Manchester with home evacuations in some areas
• significant river flooding impacts were also recorded in central and east England on subsequent days, as rain made its way through the larger river network

The FGS highlighted from:

• 4 days before Storm Christoph, a low likelihood of significant impacts (yellow) for the north of England and Wales
• 3 days before Storm Christoph, an escalation to medium flood risk (amber) – a long lead time for a medium flood risk forecast

This demonstrates the confidence we had in the conditions for such an event.

The highlights from this operational performance were:

• a Prime Minister chaired COBR held on the basis of our forecast
• that we influenced the naming of this storm as it did not meet normal Met Office naming criteria
• our service was seamless despite working 100% remotely

Sir James Bevan, Chief Executive of the Environment Agency said, “The quality of the forecasting meant that we were able to prepare in ample time on the ground, putting up our temporary barriers, operating our defences and warning and informing communities, so that people could take action and stay safe.”

Professor Penny Endersby, Chief Executive of the Met office said, “In times like these, it reminds me how important the partnership we have through the FFC is. This work by the FFC often goes under the radar, but it is absolutely integral to how we manage flooding incidents.”

3. Customer insight

Despite the challenges of COVID-19, we have still been able to carry out meaningful engagement activities.

These included:

• progressing a refresh of the FFC website, with support from the Defra digital team, involving migration to the GOV.UK platform
• undertaking testing for hosting the FGS on the Met Office Hazard Manager platform with the Met Office team - once live, the FGS will have new functionality on mobile and desktop and include ‘Areas of Concern’ maps for the first time
• developing a project plan to take forward recommendations as to how the Flood Outlook product can provide more value for decision makers
• refocusing the FFC User Group to provide better communication channels between FFC and users
• carrying out winter readiness training
• supporting delivery of seasonal flood risk messages to over 500 Environment Agency, Defra and Cabinet Office duty managers
• continuing support of the creation of a new FFC Strategic Plan by providing user insight
• introducing new extended Flood Outlook briefings - monthly calls with the Environment Agency and Natural Resources Wales, sharing Flood Outlook and seasonal brief
• developing a procedure for engaging with new users of the FGS

Through consultation with the FFC User Group in September 2020, we identified a strong demand for online training. In response to this feedback, the FFC provided:

• live web-based training for the FGS to over 250 responders over 4 sessions
• dedicated training sessions to Met Office Civil Contingency Advisors and Defra
• delivery of winter resilience training to over 500 Environment Agency tactical and strategic incident management personnel
• ‘bite sized’ on-line videos, hosted on YouTube and accessed through the FFC website
• materials for live web-based training for the Flood Outlook
• delivery of Flood Outlook training to selected users, the Environment Agency and Defra as part of a limited trial expansion of the distribution for this product

4. Service development and improvement

4.1 Improving flood forecasting production with the new Incident Management Forecast System (IMFS)

We have contributed considerable resource to the new IMFS. The work has included:

• trialling and testing functionality, feasibility and outlining the new ways of working before moving to end-to-end testing
• by July, completing the testing of hydromet services and training for all hydrometeorologists and duty managers within the FFC
• demonstrating changes to the Joint Steering Group, Directors in Incident Management and Resilience (IM&R) and the Environment Agency Executive Director of Operations
• launching the new Hydromet Services on 14 April

For the whole team it has been a huge achievement and contribution in getting the system, and new practices, into operations.

4.2 Flood Outlook Development

We have started the future development of the Flood Outlook, including:

• expanding the user base on a trial basis over the winter
• adding new users to the distribution list, including the Maritime and Coastguard Agency, Royal National Lifeboat Institution, Ministry of Housing Communities and Local Government, National Resilience, Fire Chiefs Council and Yorkshire Water
• working with Environment Agency Thames area and the Thames Local Resilience Forums to understand better how they use the Flood Outlook
• leading online training sessions to familiarise new users with the product and its features.

4.3 New Flood Guidance Statement on Hazard Manager

We have continued to work with the Met Office Hazard Manager team to ensure that user perspectives are incorporated into the FGS/Hazard Manager development. This has included testing final options and prototypes and initial development of the communications plan.

4.4 Surface Water Flooding Hazard Impact Model Lifecycle

We consolidated our learning from our first year using the model operationally, using this to inform our development. We worked alongside our partners in the Natural Hazards Partnership (NHP).

5. Forward look

Looking ahead to next year, we expect the pandemic to continue to influence our ways of working.

However, we feel sure of the centre’s ability to provide a seamless service in these unprecedented times.

If you have any questions about our performance during this year, please email us at ffcenquiries@environment-agency.gov.uk.