We have recently experienced a hardware incident with a tape volume becoming damaged:

• From 31 December 2017, half of the hindcast (enfh), perturbed forecast (pf), pressure level data (pl) are not available from tape. Note data cached on disk is still available.

Unfortunately, requests for data from a damaged tape are blocking access to all S2S data. In order to prevent blocking all S2S service via the WebAPI, we have disabled access to that specific dataset (reforecast, perturbed forecast, pressure level) until the problem is resolved.. We apologise for any inconvenience.

As of 06 Feb 2018 19:00 UTC access to all hindcasts has been restored.

We have recently experienced a couple of hardware incidents with tape volumes becoming damaged:

1. During October 2017, a large proportion of hindcast (enfh), perturbed forecast (pf), single level data (sfc) was not available from tape. Data cached on disk would not be affected, but data from tape would fail. This problem was resolved on 8th November 2017.
2. From beginning of November 2017 until 21st November, half of the hindcast (enfh), perturbed forecast (pf), pressure level data (pl) are not available from tape.

Unfortunately, requests for data from damaged tapes were blocking access to all S2S data. In order to prevent blocking all S2S service via the WebAPI, we disabled access to (2) during the specified period. We apologise for any inconvenience.

As of 21 Nov 2017  14:30 UTC access to all hindcasts has been restored.

New fixed ISAC reforecast set was added to S2S archive. The new model version date it relates to is 2017-06-08. The new reforecasts contain now newly perturbed outputs as well and the lead time has been extended to +32 days. The data availability can be discovered as usually via the dedicated S2S data portal at ECMWF.

The Meteo-France ssrd field is actually correct. The issue described previously only concerns the French seasonal forecast system but not the S2S one. However there is a newly acknowledged 10-meter wind fields issue - both the zonal and meridian components are effectively wrong. For more details go to the data issues page.

New fixed JMA reforecast set was added to S2S archive. The new model version date it relates to is 2017-01-31. Comparing to the previous set of JMA reforecasts (with the preivous model version date 2014-03-04)  it has two more year longer reforecast period 1981-2012. The data availability can be discovered as usually via the dedicated S2S data portal at ECMWF.

The problems with U/V  and geopotential fields (500 hPa and higher levels only) in pressure level outputs from KMA were fixed. The affected data in MARS was re-archived (period between the 29^th March and end of August, 2017). For more details, please visit the page about Issues with data.

All surface solar radiation downwards (ssrd) data  from Meteo-France is wrong.  Please see update from 03-11-2017 above. For more details go  to the data issues page.

The model outputs from KMA - 500 hPa geopotential fields are wrong since the 29^th March, 2017. For more details go directly to the data issues page.

The Issues with data page was updated with newly acknowledged data issues in S2S archive:

• KMA: problematic wind components fields on pressure levels
• JMA:
  
  • wrong valid times of the maximum/minimum temperature
  • wrong accumulated parameters(except for total precipitation)

For more details go directly to the data issues page.

The ISAC-CNR real-time forecast length has been increased to 32 days since Thursday, the 8^th of June 2017. Further, since the same model run date the vertical speed has been added to all archived pressure levels instead of previous 500 hPa only.

The both HMCR runs (real-time and forecast) are starting now on Thursdays instead of Wednesdays. The 1^st affected runs are from Thursday 8^th of June 2017. This change was done to facilitate the usage of S2S re-forecasts (to have them starting all on the same week day).

The results of the 1^st S2S user survey have been published (link to pdf document). The total number of 116 users answered various questions about their experience with S2S products.

A new version of JMA forecasting system (GEPS1701) has been introduced since the run on 22^nd March, 2017. More information... here.

The number of ensemble members for each hindcast year in UKMO re-forecasts  has been increased from 3 to 7. The first affected model run is from the 25^th of March, 2017. More information ... here.

A new range of near-real time forecast charts based on the Sub-seasonal to Seasonal predictions (S2S) database is now openly available at: www.ecmwf.int/en/research/projects/s2s/charts/s2s

They can be used to monitor the S2S data and assess the quality of the forecasts, as well as providing a testbed for the development of new products, for example to identify signals for extreme events at the sub-seasonal timescale. The products include ensemble mean anomalies for some meteorological parameters, Extreme Forecast Index (EFI) for 2m temperature and forecasts of the Madden and Julian Oscillation (MJO). Since S2S is a research project, the forecasts are available with a 3-week delay; they are not intended for operational use.

Currently the S2S charts are limited to six models. In future all 11 S2S models will be included and the range of products will be extended. More information will be available ...here.

The interpolation problem in all Meteo-France real-time data in the period 19.5.-16.6. was fixed. The affected data in MARS was re-archived with the corrected one on June 17. For more details, please visit the page about Issues with data.

The problem with initial conditions in some CMA real-time data in January 2015 and 2016 was fixed. The affected data in MARS was re-archived. For more details, please visit the page about Issues with data.

In the last few months we have experienced an increase in the number of users and requests accessing re-forecast data. Substantial disk space has made available in order to keep such data cached on disk. Users should experience a much better throughput, specially for re-forecasts of models with fixed configurations.

The real-time forecast frequency was changed from once per month to weekly and the length of forecast was changed from 61 to 32 days. The first date archived with this new setup is 3rd March 2016. More information... here.

For more details, please visit the page about Issues with data.

Sea-ice cover data from BoM and CMA have problems, mostly in the re-forecast. Users are recommended not to make use of this data until it has been replaced in the S2S Archive, which we aim to do in the coming weeks. This will be announced to users. For more details, please visit the page about Issues with data.

Update of ECMWF forecast system. A new version of ECMWF model (IFS cycle 41r2) was introduced at ECMWF. 

• Introduction of a new model grid: the reduced Gaussian octahedral grid;
• Horizontal resolution of the ENS increased from T_L639 / N320 to T_CO639 / O640 for ENS (Days 0 - 15) and from T_L319 / N160 to T_CO319 / O320  for ENS Extended (Days 16 - 46), where subscript C stands for cubic and O for octahedral;
• For the medium-range ENS there will no longer be a decrease of resolution at day 10: the ENS Days 11 - 15 will be run at the same T_CO639 / O640 resolution as ENS Days 0 - 10;

Click  here for full details.

A page Issues with data was created with the intention to make users aware of important issues with the data. We suggest users to 'Watch' that page so they should get notified of any issue we believe is relevant. More information... here.

We have documented a couple of cases on how to write scripts to retrieve data efficiently via the WebAPI. In order to do that one needs to know the frequency and availability of each Centre's re-forecast. These use cases are linked in the page with models' description (click on the model name in the first column there)

For example the links to BoM or CMA use cases are here:
BoM: https://software.ecmwf.int/wiki/display/S2S/BoM+re-forecast+efficient+retrieval
CMA: https://software.ecmwf.int/wiki/display/S2S/CMA+re-forecast+efficient+retrieval

The web interface to access re-forecasts was opened. The interface is available here.

The re-forecast frequency was changed from once to twice per month. More information... here.

The official launch of S2S database 

Near real-time forecasts from four data providers (BoM, ECMWF, JMA and NCEP) have been ingested routinely since January 2015.

More information... here.