Atmospheric numerical model configurations

The Met Office operational forecast suite is run 24 hours a day, 365 days a year.

The operational suite is made up of atmospheric configurations (below) and various ocean and wave models. Each model is routinely run within a given time slot, within the operational schedule. For example, the global model is run twice daily, providing forecast guidance for up to six days ahead. These 'main' runs are initialised with data valid at 0000 UTC and 1200 UTC respectively, starting around 0240 UTC and 1440 UTC, taking approximately 70 minutes to produce a five-day forecast. Approximately 20 minutes of the run time is used by observation processing and data assimilation.

Operationally, the Met Office runs a number of configurations of its Unified Model. These range from the global model, with a mid-latitude resolution of approximately 40 km, down to a high-resolution 4 km UK model.

The global model runs provide boundary conditions to each of the operational regional models and the NAE provides the boundary conditions for the 4 km UK model.

Main Operational Model Configurations
	Global	NAE	UK 4 km
Resolution	0.5625° x 0.375° (~40 km in mid-lats).	0.11° x 0.11° ~12 km	0.036° x 0.036° ~4 km
Grid points	640 x 481	600 x 360	288 x 360
Model levels	50 lid ~63 km	38 lid ~39 km	70 lid ~40 km
Forecast length	144 hrs	48 hrs	36 hrs

The Met Office also has the capability to rapidly relocate regional models to any area of interest worldwide. These Crisis Area Models (CAMs) are run in support of allied military operations and disaster relief.