Whatever mesoscale model the UKMO are using to predict where and when thunderstorms are likely to break out looks like it requires some tweaking, because this is the second day it’s missed thunderstorms that have formed across central England. The model had spotted the possibility of thunderstorms over northwest Ireland though, and the UKMO have issued warnings for that. I wonder if the SFERIC activity across the Midlands at the moment originates from medium level instability, and that’s what the rainfall radar is picking up? It’s so hard these days to identify the cloud structure with 95% of observations coming from AWS. I’ll have to take a look at the Watnall ascent at 11 UTC if there is one.
Addendum I – 1415 UTC
They’re still banging away but so far the UKMO have still not responded, or are choosing to ignore the thunderstorms, despite the white pixels, maybe it is all medium level stuff that’s not reaching the ground?
Addendum II – 1530 UTC
They would never let me do the IFC, but I reckon the Watnall ascent has all the potential to create a thunderstorm, albeit with a relatively high cloud base.
Meanwhile the storm continues to rumble northwestward into the Wirral seemingly producing a lot of very heavy rain as it does so. It does seem to be elusively slipping through the SYNOP stations that lie along its way.
Addendum III – 1840 UTC
I had been thinking that because the UKMO hadn’t issued a thunderstorm warning for this event it must have been a lot less severe than it actually was, but the 29 mm of rain reported by Shawbury ties in very well with my rainfall estimates of close to 50 mm in the highest affected areas in Shropshire this afternoon from weather radar and convinces me a warning should have been issued. I saw the event unfolding this afternoon, and the thunderstorms across Shropshire did require a warning just like the one they issued for Northern Ireland, but the Met Office refused to issue one. Thunderstorm warnings are a recent addition to the list of warnings that they now issue, but if they are going to play the warnings game they’ve got to play it right, no matter how embarrassing that can be when you occasionally miss one. The worrying thing to me about today is why they refused to issue one, was it just out of complacency, or maybe it was because they just couldn’t be bothered?