Penellype's Weather Channel

[Nicos]

Fluffy slippers at the ready!
Thanks Pen

[Greenleaves]

Hope everyone can get to the GR next week

Thanks Penellype

[Penellype]

Graphic illustration of the importance of air masses as the warm front moves through tonight. The warmest forecast temperature for the whole of the next 10 days occurs at 3am tomorrow morning:



It soon cools down again as the warm sector moves away and once again the winds swing round to the north west:



Forecasts are for York from https://www.windfinder.com/forecast/york_river-ouse

[Jay22]

Lucky you living in York, we love visiting and try to get down at least once a year. Thought about retiring there, still an option. Weather has always been kind to us too which has been a bonus!

[Penellype]

Lucky you living in York, we love visiting and try to get down at least once a year. Thought about retiring there, still an option. Weather has always been kind to us too which has been a bonus!

Capital city of God's own county - of course it's the best place to live!

[Penellype]

Another chilly day and night today, then slightly milder for the weekend as the wind swings round to the west. High pressure is toppling over us, but it is likely to be cloudy and possibly damp rather than sunny and dry.



After vast uncertainties with huge differences between model runs, things are starting to firm up slightly for next week. As the high slips further east the winds turn more south westerly, bringing milder air with less cold nights especially in the north and east. The models mostly then see a vigorous low pressure system bringing wet and windy weather in from Wednesday/Thursday followed by a sharp drop in temperature on Friday/Saturday as the wind goes back into the north.



By this time there is a lot of scatter and much can change, as shown by the ensemble chart for York:



To my untrained eye there is a change developing despite the apparent repeated pattern of a high in the atlantic. It may or may not be significant, but if you compare this chart for yesterday with the above one for Friday you will see what I mean:



While both have high to our west and northerly winds, look at America. In yesterday's chart the jet stream (roughly the thick black line) meanders over the States and the upper air temperatures are not too cold. By Friday the jet stream is almost off the chart in the bottom left corner and the blue colours are intensifying over America with a few purple patches appearing. This may amount to nothing much, but purple colours often mean a strengthening jet stream and more likely mild, wet and windy weather as the low pressures break down and flatten the ridge in the atlantic. All the models appear to be seeing this happening to some degree, but we need to remember that this is the default pattern, while what we have now is very much not, so this may be a red herring. We shall see.

[Penellype]

Next Friday wants watching - this looks seriously unfunny, and the midday run, just finishing off now, looks if anything worse.



York:



I may be emigrating.

[Greenleaves]

What does it mean in simple terms Penellype?

[Nicos]

Potential for blizzards on Friday?

Glad I'm in a green zone for a change!....I think?

[Penellype]

Nicos is correct that it shows the potential for blizzards, with extremely strong winds. The wind speeds shown (base wind 45, gusts 73) are in knots, x by 1.15 for mph, so this means sustained winds of nearly 52mph and gusts of nearly 84mph.

Basically that's severe gales all the time with hurricane force gusts, and heaving down rain, sleet or snow at the same time. Since it starts off relatively warm and raining extremely hard, the chances are high that there would be flooding too.

The forecast charts for 3am Fri 8th (timings would not be that accurate) are:

Wind


Snow


The purple areas are very heavy snow. The whole lot is moving south, and by mid day Friday the strongest gusts and heaviest snow have reached the south coast, but if this is correct it would be extremely stormy and wet/snowy everywhere for at least 24 hours.

The other models show a low pressure system, but not as extreme as this. I hope the GFS has got it wrong.

[Penellype]

The GFS has thankfully backed off the hurricane force winds today, but there is still a cold plunge towards the end of the week, with quite a bit of snow. It will also be windy from Wednesday through much of the weekend if today's runs are right. The GFS keeps it cold for about a week, with some days barely above freezing.



The cliff edge is slightly less steep than in some recent runs (hence the moderation in the forecast winds).

Other models are more keen to bring milder, wetter weather back (temporarily) at the weekend.

I'm still thinking that this repeating pattern of northerly winds followed by higher pressure then a low followed by more northerly winds is likely to continue for now.

[Greenleaves]

Pleased to hear that Penellype.....off to Durham Thursday so might get back now

[Penellype]

Pleased to hear that Penellype.....off to Durham Thursday so might get back now

Keep an eye on the snow forecast though as there could be quite a bit of it - timing uncertain at present.

[Penellype]

Milder for the next couple of days, but don't be fooled. We are still on track for a cold plunge at the end of the week, and this one will be colder than last time, with daytime temperatures not much above freezing at times. The low that will provide the windy weather for Wednesday into Thursday is going a little further north than originally predicted, delaying the snow risk until Thursday night/Friday away from Scotland. A cold weekend with snow showers is expected, with heavy snow showers a possibility.

There is the potential for rather more organized snow depending on the track of an incoming low pressure on Sunday, and it is likely to remain cold for several days.

[Penellype]

The Met Office have named the coming storm Caroline and issued yellow warnings for wind for Scotland on Thursday. There are also yellow warnings for snow and ice on Friday and Saturday covering Scotland and much of the western side of the UK.

Expect further warnings of snow, possibly for Sunday and very probably at times during next week, depending on the exact tracks of low pressure systems.

The GFS is starting to show high pressure building to the north and over Scandinavia at the end of the current run period (20th December). This would pull the wind into the east and give us a blast from Siberia, and could, if the setup was right, result in a prolonged and very cold spell. Too far away for any sort of confidence, but it is a possibility at present.