Seasonal forecast dissemination products

Browse

Description of System 3

Re-forecasts and pre-operational data

Seasonal Forecasting System 3 dissemination requirements

Seasonal forecast monthly means and monthly mean anomaly dissemination products

GRIB section 1 definition for Seasonal Forecast System 3 data

Transmission of Seasonal Forecasting System products

The dissemination supports products which can be represented as fields of values of a single parameter over a defined area. The data are represented in FM 92 GRIB code.

System 3 seasonal forecasts are run at TL159 resolution with 62 levels. Surface fields are post-processed every 6, 12 or 24 hours, depending on the field. Pressure level data are post-processed every 12 hours, and are only available on a limited set of pressure levels. No model level data are produced. Data are not produced at step 0, except for the land-sea mask and surface orography which are only produced at step 0. Each model integration runs for 215 days (5160 hours). An ensemble of 41 members is run (numbers 0 to 40) starting at 00 UTC on the 1st of each calendar month. Details of fields, levels and frequency of output are given below.

Pressure levels and surface products

Horizontal resolution

- 1.5 x 1.5 degrees latitude-longitude grid, or multiples thereof

- any spectral truncation (default T159)

- Gaussian grid (default N80) both regular and reduced

- any sub-area

Vertical resolution

- pressure levels 1000, 925, 850, 700, 500, 400, 300, 200, 100, 50 and 10 hPa

Verifying times

- T+0 to T+5160 (inclusive) at intervals dependent on a parameter

* Orography field is defined as parameter Z on model level 1 and is available for STEP=0 only
+ Parameters available at 24 hour intervals
++ Parameters available at 12 hour intervals
+++ Parameters available at 6 hour intervals
** Only available for STREAM=SFMM/SMMA
Table 10.1 Seasonal Forecasting System products

FIELD CODE	MARS ABBREV.	FIELD NAME	UNITS	NO. OF BITS/VAL.
31	CI	Sea Ice Cover +	m	16
33	RSN	Sea Dencity +	K	16
34	SSTK	Sea Surface Temperature +	K	16
39	SWVL1	Volumetric Soil Water layer 1 +	m3m-3	12
40	SWVL2	Volumetric Soil Water layer 2 +	m3m-3	12
41	SWVL3	Volumetric Soil Water layer 3 +	m3m-3	12
42	SWVL4	Volumetric Soil Water layer 4 +	m3m-3	12
49	10FG	Wind gust at 10 meters ++	m/s	16
51	MX2T24	Max 2m Tem. since past 24H +	K	12
52	MN2T24	Min 2m Tem. since past 24H +	K	12
55	MEAN2D24	Mean 2m dewpoint since past 24H+	K	12
56	MEAN2D24	Mean 2m dewpoint since past 24H+	K	12
78	TCLW	Total Column Liquid Water **	kg m**-2	16
79	TCIW	Total Column Ice Water **	kg m**-2	16
129	Z	Geopotential*	m2s-2	16
130	T	Temperature ++	K	12
131	U	U-velocity++	m/s	12
132	V	V-velocity++	m/s	12
133	Q	Specific humidity++	kg/kg	12
138	VO	Vorticity++	s-1	16
139	STL1	Soil Temperature Level 1	K	12
139	ST	Surface temperature +	K	12
141	SD	Snow depth +	m	12
142	LSP	Large scale precipitation +	m	16
143	CP	Convective precipitation +	m	16
144	SF	Snow fall +	m	16
146	SSHF	Surface sensible heat flux +	Wm**-2s	12
147	SLHF	Surface latent heat flux +	Wm**-2s	12
151	MSL	Mean sea level pressure +++	Pa	12
155	D	Divergence++	s-1	16
164	TCC	Total cloud cover +++	(0-1)	8
165	10U	10 metre U +++	m/s	12
166	10V	10 metre V +++	m/s	12
167	2T	2 metre temperature +++	K	12
168	2D	2 metre dewpoint temperature +++	K	12
169	SSRD	Surface solar radiat. downwards++	W m**-2 s	16
170	STL2	Soil Temperature Level 2	K	12
172	LSM	Land/sea mask*	(0,1)	8
175	STRD	Surface thermal radi. downwards+	W m**-2 s	16
176	SSR	Surface Solar Radiation +	W m**-2 s	16
177	STR	Surface Thermal Radiation +	W m**-2 s	16
178	TSR	Top Solar Radiation +	W m**-2 s	16
179	TTR	Top Thermal Radiation +	W m**-2 s	16
180	EWSS	U-stress +	Nm**-2	12
181	NSSS	V-stress +	Nm**-2	12
182	E	Evaporation +	m of water	16
189	SUND	Sunshine duration +	s	16
201	MX2T	Max. temp. at 2m since prev. post-processing +	K	12
202	MN2T	Min. temp. at 2m since prev. post-processing +	K	12
228	TP	Total precipitation +	m	16
3	PT	Potential Temperature ++	K	16
60	PV	Potential Vorticity ++	m2s-1Kkg-1	16
207	10SI	10 metre scalar wind speed **	m/s	12

Potential temperature and potential vorticity levels

Potential Vorticity level products are available on the level 2000 as:

- parameter PT on 12 hour intervals;

Potential Temperature (Isentropic) level products are available as:

- parameter PV 12 hourly on levels 315 and 330;

12-03-2010