The northeast of England and the southeast of Scotland have had quite a dry November so far, it does seem to be that there’s a recurring dry theme going on in this part of the country in recent times. Driest place is Albemarle in Northumberland with just 3.4 mm of rainfall so far, Leuchars in Fife is not far behind with just 4.7 mm, although I don’t seem to have a 100% reception record on rainfall reports this month for some reason.
You can trace back the low that ended up being the root cause of the flash flooding in Greece in recent days as originating from the remains of what was tropical storm Rina that crossed the UK on Saturday. The Meteorological Institute of Berlin quickly renamed it Numa, but I did think that it would cause problems as it deepened over southern Germany on Sunday. I can’t add much to the fancy graphics and smart suit of Stav Danaos (fig 1), so this animation of 06 UTC MSLP charts for this week over that part of the world will suffice (fig 2). Hopefully the plotted values are the 24 hour rainfall totals might give you an idea of how wet it’s been over parts of Greece.
Not as wet as I suspected it might have been across the southwest yesterday, although estimated accumulations on the northwest coast of Devon were in the 16-24 mm range in the 24 hours ending 06 UTC this morning (fig 1). Sunday looks a much better day across the southwest, although there’s already a clutch of heavy showers tracking S’SE across Wales this morning that looks likely to affect more eastern parts of Devon by the looks of things later this morning.
I notice that the Meteorological Institute of Berlin have now chosen to rename the remnants of ex-tropical storm Rina low Numa. Numa is quickly deepening over southwestern Germany as you can see on this 09 UTC chart (fig 2). Its producing some snow on the highest ground in the cold air to its north, but to its south it’s still mild and very windy – spot the cold front.
Well a distinct centre never formed on the low as it crossed the UK, and it behaved just as the models had forecast it would. Overnight rainfall was generally in the range of 16-32 mm in the wettest areas in the west (fig 1), but there’s still more rain to come through the rest of today, and in the very same areas, as ex-tropical storm Rina scoots by on her way to le continent during the evening. Looking a little further ahead, Sunday night looks likely to be frosty down here in the southwest of England as the northwesterly eventually dies down.
I wondered what was holding up the cold front clearance on Saturday across southwestern parts of England (fig 2), but then I noticed on the Berlin Meteorological Institutes website, that the second shallow low the follows behind the low that tracks WNW- ESE across Ireland, Wales and the southeast of England during Saturday morning, was labeled ex-tropical storm Rina (fig 1). The Met Office of course are having none of that because it wouldn’t be correct would it.
Will Rina be the finale of the Atlantic hurricane season?
The last advisory on Rina highlighted what had been yet another rather unusual tropical cyclone in 2017 (fig 3):
Rina lives on in Europe
Interestingly, that rather shallow low which was Rina was when it crosses the UK is forecast to develop into quite a deep low of 991 hPa by 12 UTC on Sunday, as it tracks southeast across the Alps into the northern Adriatic, and quite a significant feature in that part of Europe (fig 4).
Yellow Warning for rain?
Even more interestingly, so far the Met Office haven’t issued any yellow warnings for heavy rain in southwestern parts during Saturday. I just wondered if the tropical origins of the air might even enhance the rainfall in theses parts.
Running rainfall totals for the last 12 months are still a little low across southern areas of England and Wales (fig 1), although there has been a recent sharp upturn from the anomalies of earlier this year. The running total for southwest England and Wales for instance had dropped to 82% of the long-term average in late June, but have now bounced back up to 94.3% (fig 2). This data is from the gridded daily regional series maintained by the Met Office that extends back to 1931.
I don’t know how long it will persist for, but there’s some interesting line convection (squall line) associated with the cold front that’s just clearing the extreme west of Wales and Cornwall first thing this morning.
Wettest place overnight looks to have been Hurn in Dorset with 34 mm of rain between 18-06 UTC (fig 2). My estimates from the weather radar looks about 10% too low (fig 1), which at the resolution that you get from the Met Office images isn’t that bad.
It’s hard to describe in words how the rainfall so far this October has been across the British Isles, hence the odd title. Yes, it’s been extremely wet in the usual places in Snowdonia and the Lake District, with the total at Capel Curig in excess of 413 mm (16.25 inches), but in other places, usually but not always further south and east, it’s really been quite a dry month, with Shoeburyness in Essex only recording 9.9 mm (0.39 inches). So without further ado, I’ll let the map (fig 1) and the ranked table (fig 2) of estimates I’ve gleaned from this months SYNOP reports do the talking, and you’ll see what I mean.
I reckon that rainfall accumulations in the Lake District in the last 24 hours have topped 150 mm on the highest fells (fig 1). The wettest place I can see from my list is probably close to Ambleside (fig 2), with around 90 mm of rain since 18 UTC yesterday evening, although these are rough and ready estimates derived from the 5 minute coarse data that’s available on the Met Office website. A pixel is a long way at this resolution, and you only have to be one or two out to return a value from over high ground rather than lower down.