This is a reasonable site, for GFS (global forecasting system)
http://www.arl.noaa.gov/ready/cmet.html
I have also sent you a PM.
Forecasts several days ahead are likely to be inaccurate, especially in the timing. But this is the best one is going to get.
It may be an idea to also use the UK met office MSLP charts as they come out of a computer model which is claimed to be the most accurate around for the UK, for the common SW airflow.