Establishing the National Flood Forecasting & Warning Service … · 2019. 10. 11. · Each is different: e.g. runtime, language, modelling approach, spatial configuration, and data

Establishing the National Flood Forecasting & Warning Service (NFFWS)Flood Forecast Centre, Met Éireann

Matt [email protected]

Flood Forecasting Division Met Éireann

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mailto:[email protected]

River Coastal

NATIONAL FLOOD FORECASTING AND WARNING SERVICE (NFFWS)

STAGE 1 : NATIONAL AND CATCHMENT LEVEL

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Establish the Service Recruit Suitable Staff • Chief Hydrometeorologist (Appointed Spring 2018)• 6 Hydrometeorologists (4 Appointed)• 1 Principal Meteorological Officer (Competition completed) • 3 Senior Meteorological Officers (Planned Recruitment Q4 2019)• Additional Hydrometeorologist competition closed last week

Accommodation• Plans to Remodel the 3rd Floor to accommodate both the FD and FFD

are under way and will be completed by late 2019/early 2020• Build up 24/7/365 capabilities

Training Staff training is continuous throughout the establishment stage:

• Model development • Meteorological Training – In house• Hydrometeorological Training – SMHI• Hydrological Training from the OPW

Flood Forecasting Division :

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Making Ireland Weather

and Climate Prepared

National Flood Forecast and warning service

▪ Stage 1 of a Three Stage Implementation Plan

▪ Objective to develop a national scale hydrological model(s) at an hourly timestep for gauged/ungauged locations - ambitious

▪ IMDC (International Marine and Dredging Consultants) procured to identify,calibrate and trial hydrological models

▪ Develop in-house capacity: input/output datasets, hydro models (build etc.) and ancillary tools (e.g. post-processing, assimilation, visualisation, etc.)

Example diagram of a flood forecasting and warning system (Bureau of Meteorology)

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Rainfall-Runoff model types

▪ Modelling options: from lumped empirical ‘black boxes’ to physically based fully distributed

▪ Huge variety in the types of models to select – exists on a spectrum

▪ Various considerations (e.g. data requirements, model objectives, accuracy, runtime, ease of use)

▪ The most appropriate model is not always the most complex

Simple model representations of a catchment (Source: Sene, 2008)

Fluvial• 4 Models have been built and calibrated for 5 catchments• Next: operational trial of the models and 2 integrator systems

to identify any issues in the running of the models• Contract extension planned to include another 7 catchments;

Boyne, Liffey, Suir, Blackwater (Munster), Lee, Galway Bay and Erriff-Clew Bay.

Coastal• Tide and Storm Surge Forecast (TSSF) system – developing a

plan with the OPW to integrate this system into MÉ’s High Performance Computing Centre

• This will allow the model to be run on a supercomputer and will speed up the run time, it will also mean that the TSSF is part of MÉ’s operational forecast model suite

• Potential to run Ensemble versions of the TSSF


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Fluvial Models are calibrated for 5 catchments (orange) –

additional 7 planned (green)

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Fluvial Model Calibration

▪ Models chosen for trial:

1. Unified River Basin Simulator (URBS)– Don Carroll

2. WRF-Hydro – US National Water Model

3. HYPE – Swedish Meteorological Hydrological Institute

4. WFLOW – Deltares (Dutch independent research institute)

▪ Each is different: e.g. runtime, language, modelling approach, spatial configuration, and data requirements

▪ They have been built and calibrated for 5 catchments – 7 more selected

▪ Generally 2 models are outperforming the others HYPEand URBS – but other considerations

Static datasets; WFLOW model simulation for the Boyne

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Fluvial Model Performance

Comparison of modelled peak discharges in Slaney for station 12013

▪ Generally 2 models are outperforming the others HYPE and URBS – but there are other considerations

▪ IMDC trialling phase will begin soon – move towards operationalizing the models in real time using live observed/NWP data

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Data inputs

▪ Requires higher resolution inputs (hourly, grid scale) – some combination of radar and rain gauge data

▪ Identifying gaps in the existing rain gauge network

▪ CAMP stations and proposed radar network have potential for improving forecast reliability –will take time (following slides)

▪ Post-processed NWP products on the same spatio-temporal scale as the observations used for calibration Rainfall distribution (mm) across the Suir Catchment

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Observations• MÉ has ~ 25 Synoptic sub-daily weather stations,

approx. 400 daily climate stations (many of which are volunteers)

• Climate Modernisation Update Project – 60 automated (sub-daily) climate stations being installed before the end of the year, with the option to drawdown an additional 20 automated climate stations in 2020.

• This will mean an additional 80 climate stations recording weather observations in real time

• After a period of time has elapsed, the data from these stations will be used to re-calibrate the fluvial flood models

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Radar• MÉ has initiated a scoping exercise to identify and

document the range of requirements for an upgraded and modernised weather radar network to include the type of radar, locations and provide a strategic plan up to 2040

• Upgrade of the current radar network of 2 up to 5. This improvement in coverage will benefit flood forecasting as weather systems will be able to be tracked more accurately.

• Locations that are not currently well covered by radar will be included with the upgrade

• The radar data can be used by flood models in order to produce more accurate forecasts

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Operational runs

▪ Blending products: aim of reducing errors and extending lead times

▪ Ideally a combination of nowcasting and HARMONIE/ECMWF ensembles

▪ Temporal response of the catchment is important for predictability and significance of products with different lead times

Proposed Model simulation schedule

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Flood forecasting system

▪ Integrator system: interface handles import, model simulation and data processing

▪ IMDC will test two different systems; FEWS (Deltares) and MIKE Operations (Danish Hydrological Institute)

Example of the Delft-FEWS user interface

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Model and data ensembles

▪ Ensemble Streamflow Prediction – now standard approach

▪ HEPEX: A global community in Hydrological Ensemble Prediction (https://hepex.irstea.fr/)

▪ The best way to take advantage of ensemble forecasts and to make better decisions based on them? – probabilistic forecasts

▪ Hydrological model ensemble – addressing model uncertainties

Ensemble flood forecasts

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Coastal Models

▪ Exploring the transfer of the existing national coastal model (OPW/RPS)across to Met Éireann▪ Incorporate within EC Flow scheduler?

▪ Coastal Flood Forecasting Strategy to be prepared later this year

▪ Potential to develop the existing national scale coastal model – includeadditional coastal flood risk components; wind, swell, waves etc. Incorporateprobabilistic NWP inputs.

▪ Potential for high-res coupled ocean-atmosphere model to provide inputs

▪ Develop in-house capacity: input/output datasets, coastal models (build etc.)and ancillary tools (e.g. post-processing, assimilation, visualisation, etc.)

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• Position of earth / moon / sun

• Atmospheric pressure, storm intensity, stormsize, storm forward speed, angle ofapproach to coast, shape of coastline, width& slope of ocean floor, local features(barriers/defences, river outlets)

• Wave and wind components

• Swell refers to waves that develop over a longer period of time than locally-generated wind waves, and over a larger area.

• Astronomical tide

• Storm surge

• Waves

• Swell

Components of tidal / coastal flood risk

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Components of tidal / coastal flood risk

Central low pressure of a depression /

storm

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Existing National Coastal Model

Tide and surge

forecast ONLY

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SouthSouth-West

West

North-West

East

South-East

Surge Level (m)

Total Water Level (m ODM)

Astronomical Tide Level (m CD)

Tide and surge forecasts at 18 locations around the coast – uses EC HighRes (deterministic)

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Detailed forecasts – still tide and surge ONLY! Just additional locations along 5 specific sections of the coastline

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• Currently only for Tralee Bay

• Astronomical tide forecast

• Storm surge forecast

• Significant wave height, peak

period and mean wave direction

• Model uses meteorological

forecast wind and pressure data

from HARMONIE (<54hrs) and

offshore wave forecasts from

ECMWF; both deterministic

currently.

Tide, surge and ‘wave’ forecasts

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• Potentially this information could be used.• However, it does not tell us the expected wave

height in isolation. It tells us significant waveheight, peak wave period & mean wave direction.

• To ensure we are not double-counting any tide orstorm surge component from the national model, weneed to estimate wave height on its own; this cantypically be an additional 0.2 – 0.5m.

Wave forecasts

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• The EC wave model is not accurate close toshore

• The red line = model land-sea boundary• last grid point to land is not trustworthy.

Even the 2nd last may not be depending onthe surrounding grid points and thedirection of the waves.

• The High resolution WAM model has a betteridea of the Irish Coastline but it’s still notgreat near some shores.

• The finer the grid of the model the closer toshore you can get accurate Significant waveheights i.e. the better the model ‘sees’ thecoastline.

• HARMONIE – ocean-atmosphere coupling?Higher resolution!

Using NWP models to forecast swell and waves

24-hour response capability (limited)• Met Éireann has developed an on-call roster which provides

24/7 support from the Flood Forecast Centre

• The aim was to introduce a 24-hour capability in the Flood Forecast Centre, noting that there is a limited number of Flood Forecast Systems in place in the country, and that EFAS is an awareness system

• FFC staff have developed products from MÉ’s suite of Numerical Weather Prediction models; Harmonie and its Ensemble version, IREPS, as well as the ECMWF models too

• The staff have been activated a number of times to provide support to the General Forecast office


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Projected track of Ophelia: 16th of October 2017Operational HARMONIE forecast from 00UTC on 16th Oct: Valid @ 00UTC on 17th Oct IREPS forecast from 00UTC on 16th Oct: Valid @ 00UTC on 17th Oct


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Develop a Communication Strategy• This is nearing completion with excellent input from

all members of the Steering Group.

• MÉ will use its existing Web and App platform, which has a large reach (4th most popular public service website and over 500,000 downloads of the app) to help disseminate flood information

• The app uses your location to inform you if there are any warnings in operation for your location

• Later this year the App will allow users to receive push notifications for weather warnings, types and levels for any county in Ireland.

• The aim of the Communication Strategy is to use the same technology for flood alerts.

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Any questions?

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Documents

Establishing the National Flood Forecasting & Warning Service … · 2019. 10. 11. · Each is different: e.g. runtime, language, modelling approach, spatial configuration, and data