The probability forecast uses data from the Global Ensemble Forecast System (GEFS).
The GEFS is basically the GFS model run an additional 30 times using slightly different starting conditions to account for uncertainty.
Tight clustering of the runs suggests a higher degree of confidence. A wide spread indicates a range of possible weather outcomes.
The upper plot shows forecast 850hPa temperatures which are approximately 1500m above sea level. They provide a way of checking how cold or warm the air mass is and aren't subject to diurnal (day to night) variation.
The lower plot shows forecast precipitation. The snow row displays the number of GEFS runs forecasting snow. This ranges from 0 to 33.
These are the temperatures we experience. The purple lines show the average maximum and minimum.
Mean Surface Level Pressure.
If your location isn't listed pick the nearest one. Ensemble forecasts are run at a lower resolution so the data covers a bigger geographical area.
Uses GEFS data with updates at 07:15 GMT, 13:15 GMT, 19:15 GMT, 01:15 GMT
Runs out to 16 days ahead
UK winter 2022-23
UK autumn 2022 weather outlook
August bank holiday weather
Is it going to rain
Drought in eight areas of England
Daily weather by email
14 day outlook
A huge range of charts and data is freely available.
Models include UK Met Office UKV and MOGREPS-G, ECMWF, NCEP GFS, Meteo France Arpege and Arome.