I’m forever being left in a position where I could have sworn (and often do) that the BBC forecast for that day is markedly different to the one that I remember from watching on TV from the previous day. This of course is due in part (maybe a large part) to increasing senility, so to get round the problem and lack of evidence (because if you try to find some the next day, you’ll realise that the BBC are remarkably adept at removing any) I always record the weather for the week ahead. The program itself is not easy to catch, but my PVR never seems to miss it.
Anyway the purpose of this article was to examine the BBC forecast for yesterday and see how close the presenters using the best Met Office NWP got to reality. I reckon that the BBC record the program in the evening even though the program doesn’t sometimes go out till the early hours, this particular one aired at 0020 BST. So I reckon that the graphics are from the 1800 UTC model run, and the forecast steps they use to cover the next days weather the T+12 to T+30. So how well did they do on the 13th?
This chart is a clever get out because the BBC forecast never actually display a maximum temperature in a forecast as they did in the old days of magnetic symbols, and which to my mind is just as valuable as any spot value. The graphic above is displaying forecast temperatures for the specific time of 1500 UTC, and if I were to claim that they were underestimating the maximum temperatures in the parts of the southeast by more than 3°C, the first line of their defence would be is that they’re not the maximum temperatures. But to be quite honest, Nick Miller had started the whole forecast with an introduction about advection and insolation standing in front of a graphic with 31 emblazoned on it, so having become adept and how they employ social media (and a TV forecast is just another form of it) the maximum temperature they were going for was most certainly 31°C. Small point to some, but in my opinion they got caught out in many places in the east and southeast of the country, but they would never admit to it but quickly move on and talk about how tropical storm “Ian” is coming our way.
Not quite getting the maximum temperature correct was quite minor to how they mishandled the thunderstorms in some central and western areas of the country. Here is the picture at 1000 UTC and then the weather radar reality:
All the activity further east and aligned differently because the activity had nothing to do with old cold front like the NWP seemed to suggest. Let’s move onto 1500 UTC.
The model has again failed to pick up on all the severe thunderstorms that were tracking north into the west Midlands and heading for Manchester in the early evening. What’s most noticeable from either of these two BBC forecast graphics is the total lack of lightning symbols, but I suppose if the graphics just had scattered light showers there wouldn’t be any. I did hear Nick Miller say at this point in the forecast that there could be a thunderstorms over northeast Wales but that didn’t tally with the graphics.
The day seems to end with the 1500 UTC frame in the ‘Forecast for the week ahead’ forecast, as if nothing ever really happens in the evening, but it did that evening and the severe thunderstorms continued to develop and play havoc with parts of the northwest.
Severe Weather Warnings
I did check the warnings page at the Met Office last night and to be fair there was an alert one out from mid morning for heavy rain over northern England. But I’m sure there wasn’t an alert out for the thunderstorms and the even heavier rain that affected the west of Cornwall around 1800 and again at 0300 UTC the next morning. I could be wrong about this, but because there is no archive of alerts and when they are issued (as far as I know) I can’t be 100% certain.
I don’t think the forecast for the next day was accurate either in regard to the exceptional temperatures in the east and southeast, or from missing the thunderstorms and heavy rain in parts of the west and northwest. I watched some of the output for the next day through Twitter, and if that was anything to go by the press team at the BBC seemed to be more focussed on the rising temperatures in the southeast than any thunderstorms that were already occurring in the southwest of the country.