Ensemble (ENS) of forecasts providing an estimate of the reliability of a single forecast.
ENS offers "High Frequency products" until step 144:
- 4 daily runs: 00, 06, 12 and 18 UTC
- hourly until step 90
- 3-hourly from 93 to 144
Most Post-processed Products are not available at 06/18 runs or in hourly steps. An exception are Tropical Cycle tracks (set III-viii) which is available for all daily runs: 00, 06, 12 and 18 UTC.
The purchase of the "Basic Set" +72, +96, +120, +144, +168 hrs is a mandatory prerequisite for the purchase of time steps in the range 12 to 66 hours.
The following sub-sets are available from the ENS Model:
III-i: Atmospheric fields (direct model output)
These fields are provided in GRIB code.
- III-i-a Atmospheric fields - Single level
- III-i-b Atmospheric fields - Pressure levels
- III-i-c Atmospheric fields - Model Levels
- III-i-d Atmospheric field - Potential vorticity levels
III-ii: Clusters (post-processed products)
III-iii: Probabilities (post-processed products)
The products provide the probabilities of the occurrence of instantaneous and averaged or accumulated weather events at each grid point. The products are encoded in GRIB form.
- III-iii-a Probabilities - Instantaneous weather events - Single level
- III-iii-b: Probabilities - Averaged weather events - Single level
- III-iii-c Probabilities - Instantaneous weather events - Pressure levels
- III-iii-d: Probabilities - Averaged weather events - Pressure levels
- III-iii-e: Probabilities - Daily weather events - Single level
- III-iii-f: Probabilities - Tropical cyclone probabilities
III-iv: Time series of weather parameters (post-processed products)
The products consist of values of the individual members of the real-time forecast at grid points (single locations). The products are provided in BUFR code.
III-v: Extreme Forecast Index (EFI) and Shift of Tails (SOT) (post-processed products)
The products provide the EFI and SOT of single level parameters calculated over 1, 3, 5 and 10-day ranges at each grid point. The products are encoded in GRIB form
- III-v-a: Extreme Forecast Index (EFI) 1-day ranges
- III-v-b: Extreme Forecast Index (EFI) 3, 5 and 10-day
- III-v-c: Shift of Tails (SOT) 1-day ranges
- III-v-d: Shift of Tails (SOT) 3, 5 and 10-day ranges
III-vi: Ensemble means (post-processed products)
The fields are the means of the ensemble members at each forecast step. The fields are provided in GRIB code.
III-vii: Ensemble standard deviations (post-processed products)
The fields are the standard deviations of the ensemble members at each forecast step. The fields are provided in GRIB code.
III-viii: Tropical cyclones tracks (post-processed products)
Tropical cyclones tracks products are provided in BUFR code.
The tropical cyclone trajectories are computed independently for each ensemble member; a given tropical cyclone may dissipate at different times in different members so the number of members predicting a given tropical cyclone may vary through the forecast.
The purchase of the "Basic Set" (+72, +96, +120, +144, +168 hrs) is a mandatory prerequisite for the purchase of time steps in the range 12 to 66 hours.
Base times for direct model output products: 00 UTC, 06 UTC, 12 UTC and 18 UTC unless otherwise specified.