The dissemination of monthly forecast field products is controlled in a similar manner to the dissemination of data from ECMWF's medium-range forecasting system. Dissemination requirements for these products are added to the general set of dissemination requirements for each Member State - it is not necessary to update and maintain separate sets of requirements for products required from Monthly Forecasts.

Users have a choice to distinguish between daily and monthly VarEPS products on the requirement level. The language keyword "USE" will be used for this purpose. If users set 'USE=MONTHLY RUN' in their request they will get these products as one dissemination file per forecast day once a week (at the moment we run extended forecast to D+32 once a week).

Example 1:

If the request contains STREAM=ENFO,STEP=0/to/768/by/6,USE=MONTHLY RUN users will get these products only once a week disseminated as one file per forecast day. The same principal applies for any range of STEPs requested.

Example 2:

If the request contains STREAM=ENFO,STEP=0/to/768/by/6 with the keyword USE not being present or USE=OFF users will get these products:

* every day for steps 0 to 360 as one file per forecast step (six hourly) like normal EPS products and;

* once a week for steps 366 to 768 as one file per forecast day like normal monthly products;

For the hindcasts, the reference date of the hindcast (date of the real-time forecast associated to the hindcast) REFDATE=YYYYMMDD is set by default in dissemination to the latest operational Monthly Forecast cycle date and does not have to be specified in the requirements. Also, for hindcast data, the only value for the parameter DATE (date on which the hindcast is based) supported in dissemination is ALL.

The following command language parameters are common for all Monthly Forecast requirements. Language parameters not listed in this paragraph are the same as defined in 4.2.6.

Identification parameters

STREAM

ENSAMBLE FORECAST

ENSAMBLE FORECAST HINDCASTS

ENSEMBLE FORECAST HINDCASTS

STATISTICS

WAVE ENSEMBLE FORECAST

WAVE ENSEMBLE HINCASTS

[EF]

[ENFH]

[EFHS]

[WE]

[ENWH]

LEVTYPE

SURFACE

PRESSURE LEVEL

POTENTIAL VORTICITY

POTENTIAL TEMPERATURE

[SFC]

[PL]

[PV]

[PT]

USE

OFF

MONTHLY RUN

See examples 1 and 2 under

Monthly forecast

dissemination

requirements above

OFF

Date and time parameters

TIME

Gives products base time.

DATE

ALL Only ALL is supported for HINDCAST.

OFF for non hindcast data

OFF for STREAM=EFHS and TYPE=EM/ES

REFDATE

Reference date of the hindcast run, in dissemination set to latest operational cycle.

OFF for non hindcast data

Data processing parameters

RESOL

[AV]

(default 639 for leg 1)

(default 319 for leg 2 and 3)

Positive integer giving the spectral triangular truncation.

(e.g. 10 indicates T10 filtered products required. May only be used with multi-level (i.e. upper air) parameters. May also be used if spectral products are required.)

GAUSSIAN

REGULAR

REDUCED

OFF

Indicating Gaussian grid type. Gaussian grid resolution is given by the GRID parameter.

GRID

*/*

AUTOMATIC [AUTO]

If the form a/b is used, a latitude-longitude grid is defined, where:

a= grid resolution (deg.) along a latitude line (i.e. East/West)

b= grid resolution (deg.) along a longitude line (i.e. North/South)

0.25/0.25 or multiples thereof for leg 1;

0.5/0.5 or multiples thereof for legs 2 and 3;

Note that it is possible to specify different values for a and b to generate a quasi-regular grid system with a different resolution in the West-East direction from that in the North-South direction. This feature is only valid for latitude-longitude grid.

If a single positive integer is coded, it is interpreted as Gaussian grid number for grids defined as GAUSSIAN=REDUCED or REGULAR. The following Gaussian grid numbers are supported: 320, 200 for leg 1 and 160, 128, 80, 48 and 32 for leg 2 and 3.

AUTOMATIC - values for the parameter GRID will be defined automatically based on STREAM/DOMAIN as well as RESOL/ GAUSSIAN parameter values;

18-01-2011