Page History

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• We have now reached the release candidate phase of the implementation of the new IFS Cycle 46r1.
• IFS cycle 46r1 test data is available in dissemination.
• Changes in some Cycle 46r1 data are highlighted.

05 Apr 2019 

• The expected date for the operational implementation of IFS cycle 46r1 is 11 Jun 2019. We will confirm this date early in May.
• The second set of live-streamed seminars for cycle 46r1 will take place on 15 May 2019 at 09:30 BST and on 16 May 2019 at 17:00 BST.

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The following evaluation of the new cycle is based on the alpha testing.

Weather parameters and waves

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Extended output have been added in cycle 46r1, including a subset of ocean fields on the atmospheric grid.

paramId	shortName	name	Description	units	GRIB edition	Components	Test data available	Dissemination	ecCharts	Added to the Catalogue
Near-surface wind output
228239	200u	200 metre U wind component	eastward component of the 200m wind.	m s-1	1	HRES / ENS		TBC

TBC

	TBC
228240	200v	200 metre V wind component	northward component of the 200m wind.	m s-1	1	HRES / ENS		TBC

TBC

	TBC
Wave model parameters
140098	weta	Wave induced mean sea level correction	Wave induced mean sea level correction	m	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140099	wraf	Ratio of wave angular and frequency width	Ratio of wave angular and frequency width	dimensionless	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140100	wnslc	Number of events in freak waves statistics	Number of events in freak waves statistics	dimensionless	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140101	utaua	U-component of atmospheric surface momentum flux	U-component of atmospheric surface momentum flux	N m-2	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140102	vtaua	V-component of atmospheric surface momentum flux	V-component of atmospheric surface momentum flux	N m-2	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140103	utauo	U-component of surface momentum flux into ocean	U-component of surface momentum flux into ocean	N m-2	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140104	vtauo	V-component of surface momentum flux into ocean	V-component of surface momentum flux into ocean	N m-2	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
140105	wphio	Wave turbulent energy flux into ocean	Wave turbulent energy flux into ocean	W m-2	1	HRES-WAM / HRES-SAW / ENS-WAM		TBC

TBC

	TBC
Ocean parameters available at the surface, produced by the NEMO model.
174098	sithick	Sea-ice thickness *	Sea-ice thickness	m	1	HRES / ENS		TBC

TBC

	TBC
151148	mld	Mixed layer depth *	Mixed layer depth	m	1	HRES / ENS		TBC

TBC

	TBC
151145	zos	Sea surface height *	Sea surface height	m	1	HRES / ENS		TBC

TBC

	TBC
151163	t20d	Depth of 20C isotherm *	Depth of 20C isotherm	m	1	HRES / ENS		TBC

TBC

	TBC
151130	so	Sea water practical salinity *	Sea water practical salinity	psu	1	HRES / ENS		TBC

TBC

	TBC
151164	tav300	Average potential temperature in the upper 300m *	Average potential temperature in the upper 300m	degrees C	1	HRES / ENS		TBC

TBC

	TBC
151175	sav300	Average salinity in the upper 300m *	Average salinity in the upper 300m	psu	1	HRES / ENS		TBC

TBC

	TBC
* All fields are masked on land and lake points. tav300 and sav300 are masked on ocean points with depth < 300m.
Parameters on Potential Vorticity levels (1.5 and 2 PVU)
129	z	Geopotential	This parameter is the gravitational potential energy of a unit mass, at a particular location, relative to mean sea level.	m2 s-2	1	HRES / ENS *		TBC

TBC

	TBC
203	o3	Ozone mass mixing ratio	This parameter is the mass of ozone per kilogram of air.	kg kg-1	1	HRES / ENS *		TBC

TBC

	TBC
3	pt	Potential Temperature	Potential Temperature	K	1	HRES / ENS *		TBC

TBC

	TBC
54	pres	Pressure	Pressure	Pa	1	HRES / ENS *		TBC

TBC

	TBC
133	q	Specific humidity	This parameter is the mass of water vapour per kilogram of moist air.	kg kg-1	1	HRES / ENS *		TBC

TBC

	TBC
131	u	U component of wind	This parameter is the eastward component of the wind. It is the horizontal speed of air moving towards the east, in metres per second. A negative sign thus indicates air movement towards the west.	m s-1	1	HRES / ENS *		TBC

TBC

	TBC
132	v	V component of wind	This parameter is the northward component of the wind. It is the horizontal speed of air moving towards the north, in metres per second. A negative sign thus indicates air movement towards the south.	m s-1	1	HRES / ENS *		TBC

TBC

	TBC
* The perturbed forecasts for the ENS only contain the parameters pt, u and v.
Ensemble probabilities
131098	tpg25	Total precipitation of at least 25 mm	Total precipitation of at least 25 mm	dimensionless	2	ENS		TBC

TBC

	TBC
131099	tpg50	Total precipitation of at least 50 mm	Total precipitation of at least 50 mm	dimensionless	2	ENS		TBC

TBC

	TBC
131085	tpg100	Total precipitation of at least 100 mm	Total precipitation of at least 100 mm	dimensionless	2	ENS		TBC

TBC

	TBC
131100	10fgg10	10 metre wind gust of at least 10 m/s	10 metre wind gust of at least 10 m/s	dimensionless	2	ENS		TBC

TBC

	TBC
133093	ptsa_gt_1stdev	Probability of 850hPa temperature standardized anomaly greater than 1 standard deviation	Probability of temperature anomaly greater than 1 standard deviation of the climatology.	dimensionless	2	ENS		TBC

TBC

	TBC
133094	ptsa_gt_1p5stdev	Probability of 850hPa temperature standardized anomaly greater than 1.5 standard deviation	Probability of temperature anomaly greater than 1.5 standard deviation of the climatology.	dimensionless	2	ENS		TBC

TBC

	TBC
133095	ptsa_gt_2stdev	Probability of 850hPa temperature standardized anomaly greater than 2 standard deviation	Probability of temperature anomaly greater than 2 standard deviation of the climatology.	dimensionless	2	ENS		TBC

TBC

	TBC
133096	ptsa_lt_1stdev	Probability of 850hPa temperature standardized anomaly less than -1 standard deviation	Probability of temperature anomaly less than -1 standard deviation of the climatology.	dimensionless	2	ENS		TBC

TBC

	TBC
133097	ptsa_lt_1p5stdev	Probability of 850hPa temperature standardized anomaly less than -1.5 standard deviation	Probability of temperature anomaly less than -1.5 standard deviation of the climatology.	dimensionless	2	ENS		TBC

TBC

	TBC
133098	ptsa_lt_2stdev	Probability of 850hPa temperature standardized anomaly less than -2 standard deviation	Probability of temperature anomaly less than -2 standard deviation of the climatology.	dimensionless	2	ENS		TBC

TBC

	TBC
Ensemble mean / Ensemble standard deviation
10	ws *	The speed of horizontal air movement in metres per second.	The speed of horizontal air movement in metres per second.	m s-1	1	ENS		TBC

TBC

	TBC
130	t *	This parameter is the temperature in the atmosphere.	This parameter is the temperature in the atmosphere.	K	1	ENS		TBC

TBC

	TBC
* These parameters have been added at 250 hPa.
Extreme Forecast Index (EFI) & Shift Of Tails (SOT)
132045	wvfi	Water vapour flux index	EFI and SOT for water vapour flux	dimensionless	1	ENS		TBC

TBC

	TBC
132167	2ti	2 metre temperature index	EFI and SOT for weekly mean temperature (out to week 6)	dimensionless	1	ENS-EXTENDED		TBC

TBC

	TBC
132228	tpi	Total precipitation index	EFI and SOT for 1 week total precipitation (out to week 6)	dimensionless	1	ENS-EXTENDED

TBCTBCTBC

Software

ecCodes

TBC

TBC

Changes in Cycle 46r1 data

EFI/SOT in the extended-range 

With Cycle 46r1, the EFI and SOT become available in the extended-range forecast for two parameters: 7-day mean of 2m temperature and 7-day total precipitation. In contrast to the medium range, the model climate is derived from a set of 3 (rather than 9) re-forecast run dates, centred on the date of the real-time forecast initialisation (all are from 00UTC). The climate sample size is therefore much smaller and comprises 660 values compared to 1980 used in the medium range, but this does make the EFI and SOT consistent with other climate-related products from the extended-range forecasts, such as anomalies and probabilities. 

New climatology for 850hPa Temperature anomaly probabilities 

The outdated fixed climatology for computing historical 850hPa temperature anomaly probability parameters 131020 (talm2), 131021 (tag2), 131022 (talm8), 131023 (talm4), 131024 (tag4) and 131025 (tag8) is replaced by a new re-forecast-based climatology. The same climatology is also used to compute the Cycle 46r1 new (standard-deviation-related) 850hPa temperature anomaly probability parameters listed above. The new climatology is much more compatible with the real-time forecast. 

A change to the computation of maximum CAPE and maximum CAPE-shear parameters 

The two parameters 228035 (mxcape6) and 228036 (mxcapes6) namely “maximum CAPE in the last 6 hours” and “maximum CAPE-shear in the last 6 hours” respectively implemented with cycle 45r1, were computed in a complex way by combining hourly output of the model’s instantaneous CAPE (paramID=59) and CAPE-shear (paramID=228044) with a different type of CAPE, based on virtual temperature, that is used more directly by the model parametrisation where convection is active. This way of computing mxcape6 and mxcapes6 is inconsistent with the standard, instantaneous CAPE and CAPE-shear output fields provided by ECMWF hitherto. So to achieve more consistency, from cycle 46r1 we will change the mxcape6 and mxcapes6 variables to be based solely on the standard instantaneous hourly values of CAPE and CAPE-shear.

Software

ecCodes

ecCodes version 2.12.5 provides full support for the new model output parameters introduced in IFS Cycle 46r1.

Magics

Magics version 4.0.3 provides full support for the new model output parameters introduced in IFS Cycle 46r1.

Metview

Metview version 5.5.3 ecCodes version 2.12.5 provides full support for the new model output parameters introduced in IFS Cycle 46r1.

Availability of test data from the IFS cycle 46R1 test suites

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