An area of heavy rain has developed in the last hour over northeast Scotland (fig 1). It doesn’t get much more intense that 16-32 mm per hour, well actually it does, the pixels turn white with intensities of 32 mm per hour and higher. According to the UKMO analysis it looks like it’s a very active bent back occlusion that’s behind it (fig 2).
I did notice that the rain never even got a mention in the BBC weather at 12.58 pm, although we did get Sarah Keith-Lucas showing us a couple of nice pictures, one by Geoff of Histon in Cambrideshire, and the other by Alan in Topsham in Devon!
A: The short answer is yes they are. The Central England temperature series [CET] reveals that winters [DJF] are now on average 1°C warmer that they were 140 years ago back in 1878 (fig 1), and the England Wales Precipitation [EWP] series indicate that they’re also 18.6% wetter (fig 2).
It’s been a very wet 24 hour’s down here in Devon, although there seems to be a curious mismatch between the estimates of what the radar saw (fig 1), and the rainfall that found its way into the gauges of the AWS at all the various SYNOP stations across the country (fig 2). Capel Curig just 2mm? The river Culm has certainly burst its banks locally and flooded all the water meadows that surround it.
Locally in Bradninch I only measured just over 19 mm in the 24 hours, but Exeter had almost 30 mm, and Dunkeswell close to 40 mm, so either the rainfall was very sporadic, or I’ve still got a spider’s web in my AWS connected to my tipping bucket.
The sheltering effect of Dartmoor seems to have had a long reach if you look at the estimated 24 hour rainfall totals for yesterday from the weather radar network. Conversely the funneling effect of the Bristol Channel, and the resultant large rainfall totals across south Wales, with a finger of higher totals extending northeast towards the Wash was also evident (fig 1).
You would have expected the upper winds to be from around 220° which they were from the 2317 UTC ascent from Camborne (fig 2).
There’s been a wet start to March across parts of the country, the wettest place in the first 10 days seems to have been Dublin in the Irish Republic with over 4″ of precipitation (107.7 mm). A large part of these totals would have been from snow that fell in the first few days of the month, in fact the highest precipitation amounts correlate very well with the deepest reported snow depths (fig 1). That shouldn’t be that surprising, but it does make me wonder how an AWS handles the water equivalent in cold and snowy situations such as the one we experienced last week, especially when the snow is blowing around like it was.
There’s no quicker way to strip snow of high ground than a combination of mild air and heavy rain. The rivers must be in spate after a rapid thaw of the snow on Dartmoor and Exmoor brought about this way overnight by a band of heavy early morning showers tracking N’NE across the southwest (fig 1).
The cold air is still hanging on for dear life further north, so there’s quite a temperature contrast in this 09 UTC chart (fig 2). The Met Office analysis for 06 UTC reckon the rain is from an occlusion.