Ensemble forecast for London

This uses data from the Global Ensemble Forecast System (GEFS). The GEFS is a version of the GFS model which is run 30 times with 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.

850hPa temperatures (°C), rainfall (mm) and snow row

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.

2m temperatures (°C)

These are the temperatures we experience. The purple lines show the average maximum and minimum.

MSLP (mB)

Mean Surface Level Pressure.

Mean wind speed (mph)

These are average wind speeds. Gusts could be significantly higher.

Snow depth (cm)

Snow depth

UK locations

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.

London

Birmingham

Belfast

Cardiff

Edinburgh

Newcastle

Overseas locations

Information

Uses GEFS data with updates at 07:15 GMT, 13:15 GMT, 19:15 GMT, 01:15 GMT

Runs out to 16 days ahead

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• 5 day rain
• 5 day max temp
• 5 day min temp
• UK overview

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14 day UK forecast

30 day UK forecast

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UK long range

UK ultra long range

Ensemble forecast

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