Return of the easterlies

Still out there in the realms of science fiction land I know, but the last few runs of the GFS model have had pressure building strongly across Scandinavia later this week that pushes low pressure further south into central France, leaving the UK in another easterly air stream by next weekend and just in time for the vernal equinox and the real start of spring (fig 1).

Posted in: GFS

What’s the collective noun for a group of NWP models?

I wonder what the collective noun is for a number of NWP models? You know the kind of thing – a murder of crows, a murmuration of starlings, an exaltation of larks. Perhaps its simply a pile of crap? That may sound a bit harsh, but that’s the thought that ran through my mind when I compare short-range model output in this current spell of severe weather across the country. All I really want to know is how long is it going to snow, and although they all provide you with some kind of solution, they are all quite different and not that convincing. In the early 21st century you might have […]

This weeks explosive cyclogenesis

Another cyclogenetic episode this week as it looks quite likely that storm Fionn will rush eastward across central Scotland from the Atlantic at around 60 knots if the latest forecast from the GFS is correct. If I’ve done my calculations right, the low will have moved 2,678 km and deepened by 36 hPa in the 24 hours ending  at 06 UTC on Thursday – so it’s not hanging around! From the only relevant forecast chart I can find from the Met Office (fig 2), it looks like they track the low further south at 52° rather than 56° north, which I can only imagine would impact even more of […]

Monday looking reminiscent of the Christmas day snowstorm 1927

The snow threat on Sunday now looks likely to be restricted to the north of Wales, the Northwest of England, the north Midlands and Yorkshire, as an occlusion sweeps across southern England and stalls as it pushes up against colder air further north. The probability of snow might have been even higher if it happened during the night, but from the look of it this will be enough to close the Woodhead and Snake pass. It’s certainly a complicated looking cyclonic picture on Sunday as an elongated trough develops, and stretches out across central England. Two separate low centres form, one of them continues eastward into Northern Germany the […]

Memories of late November 1973

Looking at the latest long-range forecast charts from the GFS for T+192 (fig 1) and T+336 (fig 2) reminds me of the last few days of November 1973, which saw an early cold spell from a similar outbreak of northerly winds (fig 3). I had just left the Met Office (for the first time), and had started working as a trainee bank clerk for the Trustees Savings Bank at a new branch they had just opened in Dronfield, northeast Derbyshire, and can still remember the snow. It also extends the run of northerly outbreaks which started on the 29th of October with a period of approximately 7 days, that’s […]

Something for the weekend

The latest run of the GFS model (fig 1) has sided with the UKMO model (fig 2) and decided not intensify the low that runs across Central England on Saturday. It still looks a thoroughly wet day though, especially across the west of Wales and the southwest of England though, with a westerly gale along the English Channel, if this latest forecast is correct (fig 1). Sunday looks a windy day with strong northwesterly winds particularly down the east coast of England and Scotland, with wintry showers down to quite low levels in the northeast of Scotland I would fancy. I wonder if the enhanced troughing in the GFS […]

Season of mists and mellow fruitfulness

The season of mists and mellow fruitfulness feels like it’s getting into gear, at least here in south Devon, with the Culm valley full of fog this morning, after a clear and rather cool night for August, with temperatures at Exeter down to just 6.9°C. Notice the high overnight minimum temperatures from across the southern North Sea (fig 1). That speculative blog that I wrote last week about how ex-Hurricane Gert might change the zonal flow to meridional, may not have been too far of the mark, as the outlook from the GFS model for the next week looks distinctly anticyclonic across southern areas (fig 2). I wonder if […]

Storm tracks…

The excellent website have recently added a storm tracking feature to their repertoire of NWP graphical tools that they offer. I’ve never seen this kind of thing done before with NWP, and it looks like an interesting new addition, to what is already an incredible site. Unfortunately the tool only seems to work with the GEFS NWP model at the moment. I can’t work out if the vortex centres are generated by the models themselves or are generated by as they are received. It will certainly be a very handy tool for keeping an eye on extratropical lows as they ply their way across the North Atlantic […]

Zlatan – how did the models do?

How did the two main NWP models do with their T+36 forecast surface chart for low Zlatan that’s currently sat slap bang on top of Ireland at 12 UTC (fig 1). As Harry Hill would say – there’s only one way to find out…FIGHT!! Well we don’t have to resort to fisticuffs, the mark I human eyeball will do just fine. Positionally the Met Office got Zlatan’s 12 UTC position perfect (fig 2), the GFS position was around 200 km too far to the southeast (fig 3). Intensity wise the Met Office also were much closer to the ~992 hPa that Zlatan was at midday, with 991 hPa, the […]