The computation of EFI changed with the implementation of VarEPS-Monthly in March 2008. This change had to be reflected in the information stored in the GRIB Header. Therefore, we have 2 versions regarding the content of local definition 19. The layout is the same, and applications do not need to be recompiled, unless they make use of the extra information.

The two definitions follow:

Please, refer to the documentation about Implementation of VarEPS-Monthly for further information.

Definition prior to March 2008
KSEC1 element Contents GRIB octet Recommended GRIB_API keys Coded GRIB_API keys Comments
37 
ECMWF local GRIB use definition identifier.
19 = Extreme forecast index data
 41 localDefinitionNumber localDefinitionNumber
38 Class: 1 = operations 42 class marsClass
39 
Type:
 27 = extreme forecast index
 28 = extreme forecast index control
43 type marsType
40 Stream: 1035 = ensemble forecast 44-45 stream marsStream
41 
Version number or experiment identifier.
(4 ASCII characters, right justified)
 46-49 expver experimentVersionNumber
42 
Zero, for compatibility with Mars labelling
 50


43 Ensemble size. 51 ensembleSize
 ensembleSize
44 Power of 10 used to scale climate weight = F, say 52 powerOfTenUsedToScaleClimateWeight
 powerOfTenUsedToScaleClimateWeight
45 Weight*10**F applied to climate month 1, stored as an integer 53 - 56 weightAppliedToClimateMonth1
 weightAppliedToClimateMonth1
46 First month used to build climate month 1, YYYYMM 57-59 firstMonthUsedToBuildClimateMonth1
 firstMonthUsedToBuildClimateMonth1
47 Last month used to build climate month 1, YYYYMM 60-62 lastMonthUsedToBuildClimateMonth1
 lastMonthUsedToBuildClimateMonth1
48 First month used to build climate month 2, YYYYMM 63-65 firstMonthUsedToBuildClimateMonth2
 firstMonthUsedToBuildClimateMonth2
49 Last month used to build climate month 2, YYYYMM 66-68 lastMonthUsedToBuildClimateMonth2
 lastMonthUsedToBuildClimateMonth2
50 EFI order 69 efiOrder
 efiOrder
51 Set to 0 for this version of EFI(prior to March 2008) 70


- Set to zero 71 - 80


Definition after March 2008


KSEC1 element Contents GRIB octet Recommended GRIB_API keys Coded GRIB_API keys Comments
37 
ECMWF local GRIB use definition identifier.
19 = Extreme forecast index data
 41 localDefinitionNumber localDefinitionNumber
38 Class: 1 = operations 42 class marsClass
39 
Type:
 27 = extreme forecast index
 28 = extreme forecast index control
43 type marsType
40 Stream: 1035 = ensemble forecast 44-45 stream marsStream
41 
Version number or experiment identifier.
(4 ASCII characters, right justified)
 46-49 expver experimentVersionNumber
42 
Zero, for compatibility with Mars labelling
 50


43 Ensemble size. 51 ensembleSize ensembleSize
44 Version number of the latest experimental Suite(1-255) 52


45 Implementation date of the latest model cycle (YYYYMMDDHH) 53 - 56


46 Number of re-forecast years in the model climate (Currently set to 18) 57-59


47 Length (in number of days) of the climate sampling window centred over the day of the climate run (Currently set to 31) 60-62


48 Sample size of the model climate (Currently set to 0 = No climate files prepared for days between two forecast runs) 63-65


49 Version of model climate (Currently set to 0 = No climate files prepared for days between two re-forecast runs) 66-68


50 Set to 0 for the EFI 69


51 Set to 1 for this version of EFI(prior to March 2008) 70


- Set to zero 71-80