Model output discussion - proper cold spell inbound?

[ptow]

56 minutes ago, Deep Snow please said:

There's a lot of good in the short range on this model with sub-zero temps, however the back edge of this model is simply incredible for us coldies. Potential for it to deepen as well.

 

Barely below freezing for the south at night time. Guess it will feel cold in the wind. Would be interested to know what the day maxes are. Its also nearly March by that point so might feel quite pleasant out of the wind.

[frosty ground]

1 minute ago, ptow said:

 

Barely below freezing for the south at night time. Guess it will feel cold in the wind. Would be interested to know what the day maxes are. Its also nearly March by that point so might feel quite pleasant out of the wind.

Not sure the strength of the sun will be felt over night.... if it is we are is serious trouble.

[danm]

6 minutes ago, mb018538 said:

-2 by day is extremely cold in the UK - remember the January 1987 set up was about as extreme a set up as you can get here, and that gave common daytime highs of -6 to -8c....so without that set up, and bear in mind it will be the end of February and not deepest darkest mid-winter, it would be about right.  

Daytime highs of -2c, particularly in the south, is indeed quite rare. Unless you have a temperature inversion and/or some dense fog, it normally requires deep cold at the 850 level and/or good snow cover on the ground. So if we could achieve that in late Feb it will be very good. One thing to remember however, although solar energy is getting stronger, sea temperatures are at their coldest in early spring which should also help to reduce moderation of cold upper temperatures - “more likely to see snow falling at Easter than Xmas” and all that...

It’s clear that we are witnessing a rare major SSW - it would be unlucky of us to not at least get something relatively memorable out of it over the next month. 

The models are starting to show some proper cold, especially from the E/NE. Let’s hope the cards fall in our favour! 

[Ashme]

19 minutes ago, Mark Parsons said:

I would plan for a worse case scenario , if it passes with less effect then so be it.

Wait until next wknd, if it passes with less effect and you've forked out thousands of pounds, I'd rather wait

[The Northern Ramper]

At what point can I discuss these events with family and friends?

Its normally guaranteed to fail at that point.

[Met4Cast]

GFS bringing the Easterly in a little earlier on this run, nice alignment too

 

[Derecho]

Just now, Ramp said:

At what point can I discuss these events with family and friends?

Its normally guaranteed to fail at that point.

Wait till it gets to T72 before discussing, I made that mistake with the December 2012 failed easterly....

A very anticyclonic run from the GFS so far, to get some really good cold nearby we need to shift the NW Greenland polar vortex or move the high towards Svalbard, it may take a while if it does happen.

[Coopsy]

4 minutes ago, Ramp said:

At what point can I discuss these events with family and friends?

Its normally guaranteed to fail at that point.

never....remember the first rule of MOD club....

[Snowy L]

6 minutes ago, Ramp said:

At what point can I discuss these events with family and friends?

Its normally guaranteed to fail at that point.

T minus 6 hours.

[Paul_1978]

8 minutes ago, ptow said:

 

Barely below freezing for the south at night time. Guess it will feel cold in the wind. Would be interested to know what the day maxes are. Its also nearly March by that point so might feel quite pleasant out of the wind.

Yes I agree, max temps much more telling than min temps in this scenario. However there are bound to be some potentially very cold night time minimum temperatures.

The times scales quoted by @Deep Snow please are T+300 plus. The max temps are in the range 0-2C for my neck of the woods (West Yorks). 

Attached is an example from Wetter for 12 noon on 26th Feb.

Mind you it’s 2C here right now and raining. A bit grim. 

[Met4Cast]

9 minutes ago, Ramp said:

At what point can I discuss these events with family and friends?

Its normally guaranteed to fail at that point.

I have a bet with a friend that we will have snow on the ground by the 24th, so these charts are rather pleasing to me because I'd look like an absolutely genius if I win. Plus, I'll be a tenner up so win win! 

GFS slightly different in the extended regarding detail but the theme is the same, Northern blocking, cold air backing Westwards.

[Man With Beard]

EC clusters between D12 and D15 are nearly game, set and match for a ridge to the N or NNW (ending with this at D15):

Even by D10, 4 of the 6 clusters have significant cold potential (and snow potential on 3 of them):

[johnholmes]

2 hours ago, Draig Goch said:

Latest 30hpa temperature over the North Pole 

My recollections of trying to use this several years ago was that the time lag to possible cold for the UK was about 15 days? Is this what others feel is about right?

[mulzy]

4 minutes ago, Snowy L said:

T minus 6 hours.

Even then the GFS will probably flip to mild!

[Timmytour]

Just now, Daniel Smith said:

GFS bringing the Easterly in a little earlier on this run, nice alignment too

 

Last week the GFS has the far reaches of FI showing snow for most of us next tuesday.  Something it seemed to drop dropp in the 200-264.range

Won't have been the first time it has proved more accurate from further out than from the medium range. IF it modeeling it accurately now of course!

[Jonathan Rhodri Roberts]

GFS 6z looks very dry for half term next week when you compare Saturday's accumulated rainfall totals with next Thursday there's barely any difference (except in the far NW) meaning just about all of that precipitation will be falling between now and Friday 

[Purga]

Southerly tracking jet....

Any good?

[Seasonality]

Now that is some savage cold forecast for the time of year. A lobe of the vortex displaced into Scandi and North West Russia and creeping over Europe. Would be a notable start to meteorological Spring if that came off.

 

[fromey]

4 minutes ago, Purga said:

Southerly tracking jet....

Any good?

Ummmmh, I’m going to go with my gut on this and say more runs needed!!!

Edited February 13, 2018 by fromey

[timboy666]

5 minutes ago, Purga said:

Southerly tracking jet....

Any good?

yes I like that

[karlos1983]

De Bilt continues to trend colder! 

[ptow]

28 minutes ago, frosty ground said:

Not sure the strength of the sun will be felt over night.... if it is we are is serious trouble.

Hence my comment was following the day maxes question, at which point hopefully the sun will be shining. Unless of course we get lots of snow which would be great.

[Duane S.]

12 minutes ago, johnholmes said:

My recollections of trying to use this several years ago was that the time lag to possible cold for the UK was about 15 days? Is this what others feel is about right?

As a rough guide, nearer 10 days at 30mb I'd say. It's always been a very decent yardstick of impending cold though.

[snowfish1]

17 minutes ago, Daniel Smith said:

I have a bet with a friend that we will have snow on the ground by the 24th, so these charts are rather pleasing to me because I'd look like an absolutely genius if I win. Plus, I'll be a tenner up so win win! 

GFS slightly different in the extended regarding detail but the theme is the same, Northern blocking, cold air backing Westwards.

Daniel you're a lad ! Hope GFS continues the way it's going and you'll be quids in

[ptow]

18 minutes ago, Paul_1978 said:

Yes I agree, max temps much more telling than min temps in this scenario. However there are bound to be some potentially very cold night time minimum temperatures.

The times scales quoted by @Deep Snow please are T+300 plus. The max temps are in the range 0-2C for my neck of the woods (West Yorks). 

Attached is an example from Wetter for 12 noon on 26th Feb.

Mind you it’s 2C here right now and raining. A bit grim. 

Yes, its a long way off but to clarify, and in the interest of balance, for anyone that is confused at present based on the evidence we are more likely to be looking toward a standard cold spell rather than anything any of us would call spectacular.