Seasonal Hydroclimatic Forecasting System

This page provides weekly real-time subseasonal-to-seasonal hydroclimatic (HS2S) ensemble forecasts for Germany. HS2S uses ECMWF ENS extended meteorologic forecasts on sub-seasonal time scales which are disseminated each Monday and Thursday over entire Germany in this web portal. The climatology over Germany is based on DWD data. The hydrological forecasts are based on the mHM model. Our HS2S system aims to support MOSES researchers to plan event-driven campaigns (hydrological extremes and heat waves) and to investigate the evolution of upcoming heatwaves and drought events. The forecast information could also be used for impact assessment in agriculture and energy sectors in addition to environment considerations.
The HS2S system provides forecasts for soil moisture, streamflow, precipitation, near surface air temperature and river temperature. All forecasts will be updated automatically every week and issued for the next four calendar weeks.

Hydrological Forecasts

Soil Moisture Index (SMI)

Latest SMI Forecast


This figure shows the forecasts of Soil Moisture Index (SMI) over Germany for the for upcoming calendar weeks at 0.125 degree spatial resolution. SMI forecasts are based on mHM real-time ensemble runs forced by the latest sub-seasonal atmospheric forecasts provided by the European Center for Medium-range Weather Forecast (ECMWF). Hydrologic initial condition for the forecast start day is derived by forcing mHM with the latest DWD station data. Similar approach to the German Drought Monitor is considered for interpolating station data to gridded using external drift kriging. ECMWF forecasts are bias corrected with respect to the re-forecast period between 2001-2020 by removing model systematic error. Soil moisture is simulated over the total soil column (2 meter). 


Atmospheric Forecasts and Climatology

Latest ECMWF Forecast for total weekly precipitation


This figure provides climatological averages of precipitation, which are the means of weekly values of cumulative precipitation of the given calendar week computed over the 1990-2019 historical period based on DWD data. For the same calendar week, cumulative precipitation forecast from ECMWF Ensemble Extended is bias corrected and shown on the right. One can then compare climatological long-term averages with precipitation forecasts the upcoming weeks. DWD station data are interpolated using the External Drift Kriging (EDK) developed by Samaniego et al. (2011).

Latest ECMWF Forecast for total weekly precipitation


This figure provides climatological averages of maximum air temperature, which are the means of the maximum values of the variable computed over the 1990-2019 historical period based on DWD data. For the same calendar week, maximum air temperature forecast from ECMWF Ensemble Extended product is bias corrected and shown on the right. One can then compare climatological long-term averages with forecasts of the upcoming weeks. DWD station data are interpolated using the External Drift Kriging (EDK) developed by Samaniego et al. (2011).


Methodology

The real-time HS2S hydroclimatic ensemble forecasting system is under development by the department of Computational Hydrosystems (CHS) of the UFZ. It uses the latest atmospheric model outputs (ensemble extended) from the European Centre for Medium-Range Weather Forecasts (ECMWF) which are post-processed to provide forecasts of extreme events for MOSES campaigns. The climatology for a given week is obtained with interpolated data from the German Weather Service (DWD) using the same procedure used for the German Drought Monitor.

Sub-seasonal to Seasonal (S2S) Forecasts


Sub-seasonal to seasonal (S2S) forecasts aims to bridge the gap between medium-range weather forecasts (up to 10 days) and seasonal climate predictions (above a month). Compared to medium-range, sub-seasonal predictions (sometimes referred as extended) are issued on a daily basis, or once/twice per week but with increased lead times up to about 45 days. A real-time S2S forecasting system could provide tailored information for early warning of high impact extreme events.

Forecast Terminology


  • Forecast start date: The day on which a forecast is issued (e.g. July 6, 2020, Monday).
  • Forecast (target) period: Time period analyzed in a forecast. In other words, the aggregated period for which a forecast is valid. It will be provided in weekly basis based on calendar weeks in this web-page.
  • Forecast lead time: The time period between the start date and the beginning of the forecast time.
  • Initial Condition Uncertainty: The ECMWF ensemble forecasting system comprises the Ensemble Prediction System (ENS) which provide estimates of the uncertainty in a forecast. For more information, please see the link on forecast uncertainty quantificatio.


Pre-processing Data


Data generated from Earth-system models usually requires pre-processing. All information need to be converted into file formats which are conventional for the description of Earth sciences data. Big data consists of many records from in-situ observation and numerical weather prediction are processed in this stage to be compatible with other software tools in modeling chain. This step includes quality control of data and temporal aggregation of the original atmospheric model outputs (6 hourly) to the target period in which the forecast is disseminated or to the resolution required for next modeling chain. Pre-procesing of data is also a factor of the parameter of interest.

Bias Correction


(Will be updated soon.)

UFZ Developer Team and Collaborators

The HS2S is under development by joint efforts of a team consisting of postdoctoral and senior researchers at CHS department of the UFZ.

Service Manager: Husain Najafi
Contact Person and Coordinator: Luis Samaniego
Hydroclimate Forecast Team: Husain Najafi, Pallav Sherestha, Stephan Thober and Luis Samaniego
mHM team
Outreach: Andreas Marx
MOSES Coordinator: Ute Weber

Terms of Use, Copyright Disclaimer and License Agreement

  • All forecast maps disseminated by the UFZ team on this webpage are based on research experiments.
  • The material on this website does not constitute legal or other professional advice.
  • Copyrights are placed in the text, images, and all other contents disseminated on this webpage.
  • Observation records of precipitation, and air temperature which are the database for calculating climatology or bias correction of atmospheric forecasts are averaged over individual values of freely available data by the Deutscher Wetterdienst (DWD).
  • Atmospheric forecasts are used for carrying out research purposes using real-time (valid) ECMWF products. They are disseminated to the UFZ under ECMWF Standard License.
  • Research outputs (forecast maps) are openly published without any delay linked to commercial development.