>CFS Long-range
>How to use CFS forecasts

>Select a forecast member
m1 m2 m3 m4

Ensemble member 1
>Europe > Monthly 500 anomalies
M1 M2 M3 M4 M5 M6 M7 M8 M9 M10

>Northern Hemisphere
> Monthly 500 anomalies
M1 M2 M3 M4 M5 M6 M7 M8 M9 M10

>Europe > Monthly 1000mb anomalies
M1 M2 M3 M4 M5 M6 M7 M8 M9 M10

>Europe > Monthly 850 temp anomalies
M1 M2 M3 M4 M5 M6 M7 M8 M9 M10

>UK > Mean max temp
Wk 1 Wk 2 Wk 3 Wk 4
Wk 5 Wk 6 Wk 7 Wk 8
Wk 9 Wk 10 Wk 11 Wk 12
Wk13-16 Wk17-20 Wk21-24 Wk24-28

>UK > Mean 0-10cm soil temp
Wk 1 Wk 2 Wk 3 Wk 4
Wk 5 Wk 6 Wk 7 Wk 8
Wk 9 Wk 10 Wk 11 Wk 12
Wk13-16 Wk17-20 Wk21-24 Wk24-28

>UK > City temp forecasts
London Cardiff Birmingham
Manchester Glasgow

>Eu > Rainfall
Wk 1 Wk 2 Wk 3 Wk 4
Wk 5 Wk 6 Wk 7 Wk 8
Wk 9 Wk 10 Wk 11 Wk 12
Wk13-16 Wk17-20 Wk21-24 Wk24-28


>Other models
>HIRLAM (Hi-res)
>
GFS Operational
>GFS Ensemble
>ECMWF Operational
>ECMWF Ensemble
>Canadian GEM


>> How to use CFS forecasts<<
The CFS (Climate Forecast System) is produced by the National Weather Service of the United States of America.

It is an ensemble model, run four times each day.

Now, each member is valid for a past 10-day period. M1 is a control run using todays data, M2 contain the data from 20 to 30 days ago, M3 data from between 10 and 20 days again, and M4 in the most recent data up to 10 days ago. This enables a good comparison to be made as to how the model has changed over time.

CFS charts at Weatherweb are updated daily by 0530 GMT (6.30am BST).

A comparison of the various members can give an indication as to how confident one can be in the model output; should members agree, then confidence in the forecast can be higher.

A suggested method of using the forecasts is as follows:

1. Take a long view - step back from the charts and see how the weather is affecting large geographical areas, such as the whole of Europe.

2. Spot extremes - Look for any extremes of weather, heavy rain, high temperatures.

3. Visit daily - Take a look at the forecasts each day. This helps builds a picture of consistency; the more consistent the model from day to day, the more confidence you can have in it.

4. Don't take it literally - The CFS can only give guidance, not a forecast! Just because it says a particular day in 3 weeks may be warm, that doesn't mean that it will be, it should be taken that there is a chance of warmer weather during that period.

5. Look at each of the members and look for consistency between each.

One should exercise caution when using long range forecasting models such as the GFS. They should be used for guidance only, but the experience of using these is that they are better than nothing at all!