A selection of model forecast output run each day since 1st for Birmingham shown as the meteograms and 2 snapshots for 8th Septemeber, the GFS meteogram are l-r 1st, 2nd and 3rd respectively shows from top-btm 1000-500hPa Thickness (Dm), 850hPa temperature (degC), wind flags (ff knts and dd deg), Downward flux radiation (Wm^-2) (surrogate for sunshine), rainfall (mm), temperaure and dew point (degC) and last Mean Sea Level Pressure (hPa) at 6 hour intervals out to 240hrs from initialization at 00Z, the GFS graphic shows  temperature (degC/red), dew point dashed (degC), wind flags (ff knts and dd deg) and rainfall (blue bars mm) out to 15 days, the 2 snapshots cover the BI and shows pressure field (isobars white hPa) and 500hPa Geopotential height (gpdm/colour grad).  Another model i use is from Norwegian Met Service (yr.no) which is hourly for 168hours covering 7 days, reproduction is not easy as screen shots become blurred so are not shown here.

The detail can be inspected at leisure, to summarise here GFS meteogram shows near 100mm issued on 1st with 2nd to 5th being the wettest,  on both 2nd and 3rd forecast total were between 30-40mm between 5th to 8th, likewise GFS graph shows 2 peaks of rainfall on both 5th (near 8mm) and 8th (15mm) with overall total again 3--40mm, examination of accumulated rainfall from now to 18UTC on 8th gives a total again between 30-40mm, the yr.no forecasts gave 100mm issued on 1st, this reduced to 12mm yesterday and this mornings run gives 50mm between 5th and 8th.  Given the synoptic development Birmingham may well be on the northern periphery of rainfall with totals actaully nearer or exceeding along the south coast of central England - a very soggy period to come! There is also an indication that temperatures will also change quickly. For Birmingham rainfall over the next week between 50 to 80mm  will give the wettest start to September since 2008 but only around 50% of that total.

John