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Author: Ilias Pechlivanidis

Uncertainty in operational hydrological forecasting: Insights from SMHI’s services

Uncertainty in operational hydrological forecasting: Insights from SMHI’s services

Contributed by Ilias Pechlivanidis  (SMHI), member of the SMHI Guest Columnist Team Background The production of hydrological forecasts generally involves the selection of model(s) and their setup, calibration and initialization, verification and updating, generation and evaluation of forecasts. However, the precision of hydrological forecasts is often subject to both epistemic and aleatory uncertainties, with the former being related to various components of the production chain and the data used. Aleatory uncertainty refers to quantities or natural phenomena that are inherently variable over time and…

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High-resolution flood forecasting in Sweden: a status update

High-resolution flood forecasting in Sweden: a status update

Contributed by Jonas Olsson (SMHI), member of the SMHI Guest Columnist Team Traditionally, hydrological activities (observations, modelling, forecasting) at SMHI have mainly focused on Sweden’s large rivers. The largest ones are Göta River with a catchment size of ~50 000 km² and Torne River with ~40 000 km² and then there are many (often regulated) with a catchment size of 20 000 to 30 000 km². The HBV model in combination with comparatively coarse-scale geographical and (in time and space) meteorological data has worked excellently…

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Forecasting over international borders: limitations and solutions for large-scale or continental forecasting systems

Forecasting over international borders: limitations and solutions for large-scale or continental forecasting systems

Contributed by Chantal Donnelly (SMHI), member of the SMHI Guest Columnist Team Global and continental forecasting schemes already exist and are used to inform disaster management in countries without sufficient national forecast systems of their own, as inputs to operational oceanographic models and for the general interest of citizens. I have been lucky enough to have worked with two operational European forecasting systems (setting up of E-HYPE and the WET tool, as an operational EFAS forecaster and testing E-HYPE in…

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A never-ending struggle – Improving spring melt runoff forecast via snow information

A never-ending struggle – Improving spring melt runoff forecast via snow information

Contributed by David Gustafsson (SMHI), member of the SMHI Guest Columnist Team As long as we can remember, the Swedish hydropower hydrologists have tried to improve the spring melt runoff predictions by integrating snow measurements in their forecast models. Various measurements techniques have been used: traditional snow surveys with snow tube sampling; snowmobile and helicopter borne ground-penetrating radar and gamma-ray sensors; laser-scanning; and of course numerous attempts with satellite data (Photo 1). The usual conclusions have been, “yes we can…

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A timeline of developments at SMHI’s hydrological forecasting and warning service

A timeline of developments at SMHI’s hydrological forecasting and warning service

Contributed by Göran Lindström (SMHI) and Henrik Spångmyr (SMHI, Midvatten AB), members of the SMHI Guest Columnist Team The Swedish Meteorological and Hydrological Institute (SMHI) has a long tradition in developing customized products and services, as well as 24/7 production of forecasts with early warnings. In this blog, we summarize the development over time of SMHI’s hydrological forecasting and warning service. The first hydrological forecasts at SMHI date back all the way to 1913. Statistical methods for converting winter precipitation…

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