Met. Office Operational NWP Product Changes March 2010


These pages describe the changes made to the operational numerical analyses and forecast data obtained from the UK Met. Office Unified Model (UM) during March 2010. The dataset consist of global and mesoscale fields of various meteorological parameters on a number of vertical levels. Both analyses and forecast data up to 12 hours (in some cases) are available. Infrastructure support in retrieving these data is provided by the Met. Office.

Changes for PS23 were implemented in 2 parts:

1) global model horizontal resolution upgrade from N320 to N512 (40km to 25km) plus assimilation resolution N108 to N144 (120km to 90km) before December 2010;

2) remaining scientific enhancements. Parallel Suite 23 (PS23)


PS23 was implemented on 9 March. There are a number of significant model changes and the impacts on downstream systems and services. The key changes are:

Technical Information on the main changes

A significant change to the operational global model was implemented on 9 March as tested in Parallel Suite 23. A major package of model and assimilation upgrades had been developed aimed at improving performance through enhanced horizontal resolution, key components comprising:


A significant change to the NAE model was also implemented at the same time with an increase in vertical levels from 38 to 70 (bringing the NAE into line with the global model). A combined physics and data assimilation package has also been implemented following an extensive period of testing. The key components being:


The operational global ensemble system, MOGREPS-G, was upgraded in line with the global deterministic forecast model. The horizontal grid spacing was reduced from 90 km to 60 km and the number of levels was increased from 38 to 70, with the model top raised from about 40 km to about 80 km. At the same time the model physics was updated to the latest 70L version, along with the implementation of a second-generation stochastic kinetic energy backscatter scheme. The global ensemble forecasts skill, based on ranked probability scores, showed generally strong advantages - consistent with improved performance of the global model. These improvements have also been implemented in the research medium-range ensemble system, MOGREPS-15. The horizontal resolution of the regional ensemble, MOGREPS-R, was improved from 24 km to 18 km, leading to some improvement in forecast scores. At this parallel suite the model levels were unchanged. It is planned to upgrade to 70 levels and introduce significant physics improvements in parallel suite 24; initial trials of the 70 level configuration have shown very promising results.

Who to Contact

General queries about these pages and access to the data should be directed to the BADC support line. Your query should be answered within one working day. When follow-up work is required, the BADC support will carry out the work as quickly and efficiently as possible, and in any case, the user will be kept informed of progress.