Figure 1 – 24 November 2015
Figure 2 – 27 November 2016
Figure 3 – 22 November 2017
You can tell just by looking at these sea surface temperature charts since 2015 (figs 1-3) that there’s been considerable warming going on in the last two years. The cold anomaly that was a feature for so long in the central Atlantic is now less intense and much smaller a feature than it once was. It’s shifted and has been squeezed further northeast towards the southeast coast of Greenland and the opening of the Labrador Sea. The other notable difference that’s appeared in recent months is the area of warmer SST anomalies ~1500 km to the west of Portugal (42N 17W), a warm blob if you like.
The warm blob and this coming winter
To be honest I don’t have a clue if this warm blob will have the slightest effect on the weather in the British Isles this coming Winter. It would be nice to think that the area of warmer SST might weaken the Azores high in some way, and that might increase cyclonic development in the southeast Atlantic which will run northeastward towards Biscay – who knows. Looking at the actual MSLP anomalies (fig 3) for so far this month, it’s true that the Azores high is displaced further to the northeast, but all this has done has been to increase the strength of the zonal flow across the Atlantic. In fact everything seems to be enhanced in some way, if you look at the underlying anomalies (red dashed line) both highs and lows have been more intense in the first three weeks of November 2017 than usual.
Figure 3 – Data courtesy of NOAA/NCEP reanalysis
It might be thinner than ever, but Arctic sea ice this Autumn is doing much better than it did last year, with the sea ice extents up by around 800,000 square kilometres at 88.2% of the 1981-2010 long-term average, compared with being only 81.0% of average in November 2016 (fig 1).
In the Antarctic things are also not quite as dire as they were last Autumn, and although this Autumns sea ice extent is tracking well below the x 2 standard deviation area (light grey) at 91.6% of the 1981-2010 long-term average, it’s almost a million square kilometres higher than at the same time last year (fig 2).
Provisional maximum temperatures in Central England temperatures for yesterday (Wednesday 22nd of November) were the highest for that particular day since 1947. The provisional maximum of 14.7°C was a full 6.84°C above the 1981-2010 long-term average, and the minimum of 11.2° was a massive 8.27°C above average.
I can’t quite understand the Met Office with regard to warnings, they seem to be more concerned with issuing ice warnings for overnight than they do for strong winds for today. The strong westerly wind is continuing to blow fresh occasionally strong with gusts generally in the range 40 to 50 mph. This is a chart of all today’s gusts to gale force or higher (fig 1).
Figure 1 – Courtesy of OGIMET
The latest run of the GFS model maintains the cold cyclonic northwesterly theme across the British Isles for the next week or so, with a succession of vigorous lows crossing the north of Scotland en route for the Baltic. As each low tracks across it allows a milder WNW flow of for a short time, before cold air re-establishes itself in a NW or N surge. All this of course comes with a government health message that all this NWP stuff could all be science fiction and can damage your health. I know I’ve said this before but these forecast charts are very reminiscent of November 1973 to me.
Later tonight and into the early hours of Friday could get interesting over southern England, with a low tracking E’NE along the English Channel (fig 2), which could bring a spell of wet snow to the highest ground (>200 M). Yes I know, ‘high ground’ is not usually synonymous with ‘southern England’, but in this blogging game sometimes you have to clutch at straws to eek out a possible story.
Figure 2 – Courtesy of OGIMET
Earlier this week the GFS did suggest that a deepening low would threaten a more widespread area of snow across the north of England and Wales. That threat has now all but vanished, as that low is now forecast to track further south across northern France without much in the way of deepening (fig 3).
Figure 3 – Courtesy of OGIMET
Might have been hasty saying that there was a risk of wet snow on high ground in the south overnight – the Met Office don’t see any likelihood of that happening (fig 4) – that’s what you get I suppose when you let an old observer like me have a go at forecasting!
Figure 4 – Courtesy of the Met Office
An area of overnight snow has spiralled across the northeast of Scotland overnight, and put a blanket of powdered snow down on all higher ground as this webcam of Cairngorm from Inverdruie shows (fig 1). Winds have now picked up on the summit and temperatures seem to have levelled off at around -6°C after the clearance of the occlusion like feature (fig 2).
It’s no surprise that there was such widespread flooding across the northwest in England and Wales yesterday with these kind of accumulations (fig 3).
I have seen many a named stormed storm of the last three years not produce as many gale force gusts as we saw overnight in England and Wales (fig 1). None of them on land topped 60 mph but all in all it was a wild and windy night that the rain washed away, no where have I heard that line before.
Here are the 24 hour rainfall totals till 06 UTC this morning in inches for a change (fig 2). Large totals as was expected over Snowdonia and northwest England, with Shap in Cumbia the wettest of the SYNOP reporting stations with 3.27″.
A very windy day across England and Wales today. The chart above shows all gusts to gale force since 15 UTC yesterday (fig 1), I should have perhaps restricted the analysis to midnight but what the hell. Full gales proper, have been confined to coastal areas in the far southwest of England and west Wales and over higher ground in north Wales and northern England. So the Met office were quite correct in not making ‘Reinhard’ storm Caroline. The winds are particularly ferocious across the northern Pennines at the moment ahead of the cold front, the mean speed on Great Dun Fell at 15 UTC was 69 mph with gusts to 89 mph (inset anemograph), that coupled with the torrential rain must make any light that maybe shining in the window of Greg’s hut look very welcoming for anyone daft enough to be attempting that part of the Pennine Way today.
A big thermal contrast across our part of the world today, with the temperature at Gravesend as high as 16.1°C at 12 UTC, but only around 3°C across the North of Scotland. I couldn’t resist doodling on the 12 UTC chart and overlaying the approximate positions of the frontal systems (fig 2), don’t worry if it looks far too simple, I’m sure that it’s a lot more complicated that, or should I say it will be in the Met Office analysis.