Rather bizarrely the Met Office finally did get round to issuing a fog warning at 1546 UTC this afternoon, even though visibilities had been less than 100 M all day in the areas that the warning was intended for. It seems to me that someone else is reading these missives of mine other than my 23 regular subscribers…
Here for example are today’s observations from Yeovilton. The visibility was no better than 200 M all day and the maximum temperature was only +0.6°C, so for much of the time the fog could have been freezing.
These observations from as close as 3 miles away at Exeter airport show how visibilities had been reported by the AWS as 100 M since 0900 UTC in the morning, ironically they improved at 1600 UTC as the warning was finally issued.Meanwhile at Chivenor in North Devon they had also had been reporting fog since 0500 which persisted all day with visibilities 100 M or less for much of that time.
I don’t know what’s going on at these places but surely the aviation bench must have been pushing out TAF’s in the southwest with fog in them and issuing warnings to various authorities, obviously forecasters don’t do much in the way of interacting or looking out the window these days. The fog didn’t need to thicken up I’m afraid, it had been there all day in Devon, Somerset and west Dorset.
In what has been quite an unusually foggy day here in Bradninch Devon, the fog has thinned enough in the last hour to allow a glimpse of the sun just as it was starting to set! Here’s the thermograph from Exeter airport showing just how cold a day it’s been locally.
According to Ben Rich and Holly Green on the BBC TV weather at lunchtime, this big blob over Dorset, Somerset and East Devon is just a fog patch, well you could have fooled me! Here are the latest observations from 1400 UTC, I would suggest if it’s not budged all day, and as it’s now 1500 UTC, it might even thicken up a bit, not that I want to tell you how to do your jobs that is.
We live with a mile and a half of the M5 and at the moment (2.30 PM) we have a visibility of around 100 M. I have been retired for almost 5 years now, and in that time I’ve never seen fog as thick as this persist as it’s done today in Bradninch. I would have thought that the Met Office would have a warning in force this afternoon of fog for drivers on the motorways and roads across East Devon, Dorset and Somerset. But the warnings board on the Met Office website is as you can see completely blank.
So how thick does fog have to get before a warning is issued by the Met Office?
Interesting question, obviously the answer is thicker than 100 M, or they would already have a warning in force to cover a motorway and busy regional airport…
View from the Beacon above Bradninch this morning
If anything this morning’s fog has become a lot more widespread over Dorset and Somerset, and as temperatures are still sub-zero at places such as Yeovilton, it could still be of the freezing variety. In East Devon the fog has thickened up as the temperature went above zero, and the visibility at 1230 was probably around 200 metres with the sky obscured. A quick walk up to the Beacon (our local viewpoint at ~215 M) revealed that the inversion here at that time must have been at the 600 feet level, although it was a fuzzy rather than a sharp inversion if the makes sense, but the sun was shining from a lovely blue sky.
I’ve just been watching Ben Rich on the BBC TV forecast at 12.57 PM, and obviously he can do the weather forecast without looking at the latest observations or satellite imagery, because he never even mentioned that Exeter airport (-0.3°C and 100M) and Yeovilton (-1.4°C and 50M) are still in fog – quite incredible! He did manage to say in his intro though that he was a Weather Forecaster, and as far as they were concerned, today was the start of meteorological winter.
No blackfrost this morning in Bradninch, just fog and a hoar frost as temperatures dipped to -3.6°C overnight. The fog is very easy to pick out in this visible satellite image filling the Exe and Culm valleys, there’s also a strange patch of stratocumulus over Cornwall, where did that come from? Here are the overnight [18-06] minimums from this morning’s SYNOP reports.