Dissemination products

• Verifying times available
• Parameters
• Horizontal resolution and domain
• Vertical resolution

Dissemination products are available only up to 78 hours. The extra steps are processed for backup purposes to ensure Member States get the expected data at all times. Back-up arrangements are made by changing the forecast base time (and date if necessary) in the dissemination products and indicating that data is from a previous forecast run by using the generating model identifier in the GRIB header, 6 indicating a six hours old forecast and 12 as twelve hours old one. Since December 2007 users can choose not to receive backup product from ECMWF (using OPTION=NOBACKUP) in which case forecast time steps 81, 84, 87 and 90 can be requested

Full fields for both analysis and forecast data are allowed in the dissemination system.

Verifying times available

- analysis at 18, 00, 06 and 12 UTC

- forecasts at 3 hourly intervals from 3 to 78 hours, based on each analysis cycle

Parameters

Parameters available out of the BC Project are as listed in table 4.2 (same as for the main deterministic forecast)

Horizontal resolution and domain

- 0.125 x 0.125 degrees latitude-longitude grid, or multiples thereof

- any spectral truncation

- the Gaussian grid appropriate to the forecast model in use

- any sub-area

Vertical resolution

Upper air parameters are available as follows:

- pressure levels: 1000, 925, 850, 700, 500, 400, 300, 250, 200, 150,

100, 70, 50, 30, 20, 10, 7, 5, 3, 2, 1 hPa

- model levels: currently 91 hybrid coordinate level