GribStream

GribStream Blog

DWD ICON-D2 high-resolution forecasts are now on GribStream

GribStream | Published |
icond2 iconeu aromefrance dmidini ifsoper

GribStream now supports DWD ICON-D2: convection-permitting forecasts for Germany and neighboring countries at approximately 2.2 km, refreshed every three hours through 48 hours.

GribStream now supports DWD ICON-D2 as icond2: convection-permitting deterministic forecasts for Germany and neighboring countries at approximately 2.2 km, refreshed every three hours with hourly guidance through 48 hours.

ICON-D2 is Deutscher Wetterdienst's model for the very short range over Central Europe. Its fine regional mesh is designed to represent deep convection and terrain-driven weather more directly than broader European and global models, while eight daily cycles repeatedly incorporate the latest atmospheric analysis.

The initial GribStream collection exposes 63 DWD single-level fields. They cover not only temperature, humidity, wind, pressure, clouds, and precipitation, but also solar radiation, surface energy fluxes, snow state, runoff, visibility, present weather, convective diagnostics, and synthetic Meteosat brightness temperatures.

DWD ICON-D2 2 meter temperature over Germany and neighboring countries on the 0.02 degree grid
DWD ICON-D2 2 m temperature valid at 00:00 UTC on July 27, 2026, from the July 26 00 UTC cycle. The map uses all 754,862 populated cells in the regular 0.02° source field and preserves the model domain's missing outer edges.

A Convection-Permitting Forecast For Central Europe

DWD describes ICON-D2 as its high-resolution model for very-short-range forecasting over Germany and neighboring countries. The underlying model has approximately 2.2 km horizontal spacing and 65 atmospheric levels, with a forecast range of 48 hours.

At this scale, ICON-D2 operates in the convection-permitting class. Deep moist convection is represented more directly instead of being wholly delegated to a coarse-grid convection parameterization. DWD identifies several phenomena for which this regional detail is especially important:

  • deep convection and squall lines
  • intense precipitation and flash-flood situations
  • flow over complex terrain, including Foehn and downslope winds
  • low-level clouds, ground fog, and visibility
  • small-scale wind, temperature, and precipitation gradients

Convection permitting is not the same as storm certainty. A thunderstorm can be physically represented and still develop too early, too late, or a few kilometers from the observed location. ICON-D2 provides a detailed deterministic scenario, not a probability distribution.

KENDA Builds The Starting Analysis

A 48-hour forecast depends heavily on the current atmospheric state. ICON-D2 receives its initial conditions from DWD's KENDA system, the kilometre-scale ensemble data-assimilation framework used with the regional ICON model.

KENDA's Local Ensemble Transform Kalman Filter combines recent observations with a short-range ensemble. The resulting ensemble statistics allow the analysis corrections to vary with the weather situation rather than applying one fixed spatial relationship everywhere. This helps place moisture, temperature, wind, clouds, and precipitation systems into a dynamically consistent starting state.

DWD's ICON-D2 model documentation covers the operational model configuration, data assimilation, physical parameterizations, and verification in greater detail.

Eight Fresh Forecasts Every Day

ICON-D2 runs every three hours, and every cycle reaches the same 48-hour horizon in the current GribStream collection.

Source cycles Lead times Published interval Operational role
00, 03, 06, 09, 12, 15, 18, 21 UTC +0 through +48 hours Hourly Frequently refreshed very-short-range guidance

That cadence is useful when forecast freshness matters. A logistics, power, aviation, hydrology, or event-planning product can move to a new analysis every three hours while retaining a consistent two-day outlook. GribStream keeps the latest five days of cycles for recent-run comparison, verification, and short backtests.

Coverage From The North Sea To The Alps

DWD's public regular-grid product spans 43.18N to 58.08N and 3.94W to 20.34E on a 0.02° latitude-longitude grid with 1,215 by 746 cells.

The populated model footprint includes Germany, the Netherlands, Belgium, Luxembourg, Switzerland, Austria, and Denmark, together with portions of France, Italy, the Czech Republic, Poland, and other neighboring areas. It covers several weather regimes within one physically consistent forecast:

  • North Sea and Baltic coastal weather
  • the North German Plain and major river basins
  • low mountain ranges across central Germany and neighboring countries
  • the Alpine arc and its Foehn-sensitive valleys
  • western and central European transport and electricity corridors

The public 0.02° grid and the atmospheric model mesh describe different things. ICON-D2 performs its forecast calculations on ICON's native triangular grid at approximately 2.2 km spacing; DWD publishes this collection on a regular latitude-longitude grid for downstream use. The rectangular output envelope includes missing cells outside the valid regional footprint.

63 Fields Beyond A Basic Weather Forecast

The icond2 collection is surface-focused but scientifically broad:

Group Representative DWD fields Applications
Near-surface state T_2M, TD_2M, RELHUM_2M, U_10M, V_10M, PS, PMSL Energy demand, agriculture, transport, wind exposure, and environmental models
Weather and clouds WW, VIS, CLCT, CLCL, CLCM, CLCH, CEILING Fog and visibility, aviation, outdoor operations, and cloud-dependent products
Convection and precipitation CAPE_ML, CIN_ML, TOT_PREC, RAIN_CON, RAIN_GSP, SNOW_CON, SNOW_GSP Thunderstorm context, hydrology, precipitation type, and winter operations
Solar and surface energy ASWDIR_S, ASWDIFD_S, ASOB_S, ATHB_S, ALHFL_S, ASHFL_S Solar generation, surface energy balance, agriculture, and thermal applications
Snow and water H_SNOW, W_SNOW, RHO_SNOW, SNOWLMT, RUNOFF_S, RUNOFF_G Snowpack, road treatment, catchments, runoff, and mountain planning
Observation-like diagnostics SYNMSG_BT_CL_IR10.8, SYNMSG_BT_CL_WV6.2 Forecast visualization and comparison with Meteosat imagery

The synthetic brightness temperatures are calculated from the model atmosphere. They resemble selected Meteosat SEVIRI channels for comparison and diagnosis, but they are not satellite observations.

Time Meaning Matters

GribStream preserves the DWD field names and makes each field's temporal statistic explicit:

Example info Interpretation
T_2M "" Value at the valid time
TOT_PREC "acc" Total precipitation accumulated from the model run start
ASWDIR_S "ave" Direct short-wave radiation flux averaged from run start to valid time
VMAX_10M "max" Maximum 10 m wind over the source-reported interval
TMIN_2M "min" Minimum 2 m temperature over the source-reported interval

These distinctions prevent common analytical mistakes. Subtracting successive TOT_PREC values yields interval precipitation, while comparing two ASWDIR_S values directly compares means over different averaging periods. Maximum and minimum fields describe an interval extreme rather than an instantaneous state.

The ICON-D2 model page lists every available name, level, and info tuple together with its lead-time coverage.

Where ICON-D2 Fits

ICON-D2 is strongest when fine Central European detail and fresh initialization matter:

  • use icond2 for hourly, approximately 2.2 km deterministic guidance through 48 hours
  • use DWD ICON-EU for broader European coverage through five days
  • use Météo-France AROME for 0.01° guidance centered on France
  • use DMI HARMONIE DINI for 2 km surface guidance over Northwestern Europe
  • use ECMWF IFS for global context and a longer deterministic range

For decisions sensitive to exact thunderstorm location, flash flooding, peak gusts, or fog onset, combine ICON-D2 with observations and ensemble guidance. For cross-border systems, the overlap with other high-resolution regional models also supports useful model comparison.

Open Data With Attribution

DWD publishes ICON-D2 through DWD Open Data without account registration. The data may be reused commercially or non-commercially under CC BY 4.0, subject to attribution.

GribStream identifies Deutscher Wetterdienst as the creator and links to the official source. Applications that republish ICON-D2 information should preserve DWD attribution.

Start Here

Sources

Related models

icond2 iconeu aromefrance dmidini ifsoper
Try GribStream