Model output discussion - mid-winter

[SLEETY]

39 minutes ago, Daniel* said:

 

Wonder if any of Ventrice’s predictions for bitterly cold weather in Europe will come true,man’s as useless as any of these other long ranger weather predictions ,using the models.Might as well just take a guess yourself ,probably be more accurate

[CK1981]

27 minutes ago, Frosty. said:

In a nutshell, if you're not a fan of mild weather you should be happy with the latest model trends which clearly show an increasingly cold zonal cyclonic pattern on the way next week which may then veer to an even colder arctic maritime with plenty of opportunities for snow as well as lots of frosts including sharp / severe frosts over the snow fields at times, especially further north..this could turn into a very rewarding january for coldies, hopefully that goes for february too!!❄❄❄❄❄❄❄❄

.....unless you live in the south, where it’s looking far from exciting according to the latest model output ?

[ACCOUNT DELETED]

47 minutes ago, Daniel* said:

 

Should that be US OR Europe? It seems every time the USA gets a big freeze, it fires the jet up and gives generally milder or less cold weather in Europe with snow restricted to high ground. 

[bluearmy]

4 minutes ago, Draig Goch said:

Should that be US OR Europe? It seems every time the USA gets a big freeze, it fires the jet up and gives generally milder or less cold weather in Europe with snow restricted to high ground. 

Not with a Greenland high although that graph doesn’t necessarily sing a greeny ridge to me - would require a much larger neg return on the NAO

[Chevron12345]

4 hours ago, andymusic said:

Wednesday

Second chart shows a lot of rain for the south and south wales. As bluearmy said there isn't much to be excited about unless you live at elevation.

3 hours ago, andymusic said:

let it snow let it snow let it snow

? Not sure why you keep posting these charts. Yesterday a chart you posted showed more snow in Portugal and Spain than anywhere in the UK.

[Daniel*]

9 minutes ago, Draig Goch said:

Should that be US OR Europe? It seems every time the USA gets a big freeze, it fires the jet up and gives generally milder or less cold weather in Europe with snow restricted to high ground. 

Both possibly. A blocked Atlantic profile would throw a spanner in the works for that. 

[Mucka]

3 hours ago, bluearmy said:

I don’t mean near the coast - I mean areas which have no upland between them and the coast 

if I posted the posts saying how snowy next week is going to be I would use the next 2 pages up!

streamers (as nick mentioned) can’t be discounted but they will be localised 

 

Mods, please move to regional thread if necessary.

My take Blue,

I live pretty much in a valley, South Manchester, and often see rain where others see snow.

I am fully expecting snow to fall here over the period.

Accumulations?

I expect to at least see a transient covering at some point over next week.

Snow showers could well be organised and prolonged for this region and with overnight temps expected to dip below zero these showers will very likely give overnight accumulations in places.

Whether they stick around through the following day is another matter as daytime showers will likely be a mix of sleet/hail and wet snow but again these situations showers can merge to give periods of heavy wet snow which will accumulate temporarily even to low levels.

What often happens is these start as rain or sleet but as the freezing level drops turn to wet snow - a slushy wintry mix but again overnight proper snowfall can occur.

That is my experience with these set ups and as others in the NW will know I am usually cautious with PM flow bringing snow to low levels but those are usually just back edge cold from systems passing to the N - the sustained flow with a strong polar mix should make a difference here.

As for the shortwave runners, GFS is very good at picking out these features and overall I think it has been very good at modelling this set up so far - it certainly looks like a very credible scenario.

Sometimes we see what is first modelled as a shortwave later blow up into a low and cut off the cold feed and bring countrywide rain, hopefully not this time.

Even if it doesn't fully mature it could easily track to far North and bring rain anyway and even in a best case scenario there will be a rain/snow/dry divide. Someone could get pasted, others could drown in tears.

So, not expecting a winter wonderland here, just a slushy wintry mix, but not ruling out a decent fall either. Those in the NW with some height on their side should do well.

Edited January 12, 2018 by Mucka

[Daniel*]

@Bring Back1962-63 keep it as you were!

It aided in your distinction. I find that smaller font not as easy on the eye this thread is here for it to be ‘consumed’, if you don’t like a post taking up a big chunk of page then you ought to care about more pressing matters. I for one had no issues. You do not do these long posts too frequently so what does it matter..

to keep on topic it’s going to be cold some models suggest so. 

[Weather-history]

3 hours ago, Nick F said:

Agree, although dew points looks low enough for snow to fall to lower elevations in any showers, the surface temperatures in such a long-track and strong maritime polar flow will be too high to support sustained snow cover away from higher ground or where snow showers are continuous. Would need a low/wave to bring a prolonged fall of snow to lower the ground temps then winds to fall light following the clearance of the low/wave, but that looks unlikely in such a mobile/strong WNW flow. But I think many will see snow falling, but any accumulations temporary and slushy away from high ground.

However, there could be a lot of graupel in these showers as it looks pretty convective. Graupel tends to last longer and accumulates quicker than snow especially on grass, so if get frequent graupel showers, it could turn very white. 

Edited January 12, 2018 by Weather-history

[ACCOUNT DELETED]

3 minutes ago, Weather-history said:

However, there could be a lot of graupel in these showers as it looks pretty convective. Graupel tends to last longer and accumulates quickly than snow especially on grass, so if get frequent graupel showers, it could turn very white. 

We had some torrential hail showers on the coast in South Wales last month. The ground turned white with some decent accumulations  and the kids went out on their sledges. Seems like hail is the new snow here lol

Edited January 12, 2018 by Draig Goch

[karyo]

11 minutes ago, Mucka said:

 

 

As for the shortwave runners, GFS is very good at picking out these features and overall I think it has been very good at modelling this set up so far - it certainly looks like a very credible scenario.

Sometimes we see what is first modelled as a shortwave later blow up into a low and cut off the cold feed and bring countrywide rain, hopefully not this time.

This is a fear of mine regarding those shortwaves as I have seen it happen many times before. Something to watch in the next few runs and hope that it is a shallower feature.

[offerman]

38 minutes ago, SLEETY said:

Wonder if any of Ventrice’s predictions for bitterly cold weather in Europe will come true,man’s as useless as any of these other long ranger weather predictions ,using the models.Might as well just take a guess yourself ,probably be more accurate

Absolutely spot on. Great post. The charts chop and change and no one but no one can get it right its as you say guesswork.

[karlos1983]

5 minutes ago, offerman said:

Absolutely spot on. Great post. The charts chop and change and no one but no one can get it right its as you say guesswork.

Can't agree with that.... it's educated guess work..

[andymusic]

32 minutes ago, Chevron12345 said:

Second chart shows a lot of rain for the south and south wales. As bluearmy said there isn't much to be excited about unless you live at elevation.

? Not sure why you keep posting these charts. Yesterday a chart you posted showed more snow in Portugal and Spain than anywhere in the UK.

the low spinning through in the middle of next week could go further north or south, but generally speaking will offer wintry weather as well as possibly rain, but could also offer blizzards in places, and the other chart quite clearly displays coverage of snow over the UK for the benefit of people who keep saying there won't be any lol

[Iceaxecrampon]

06z

Slider then a bit of an Easterly?

 

More than enough to keep everyone happy.

[mulzy]

28 minutes ago, karyo said:

This is a fear of mine regarding those shortwaves as I have seen it happen many times before. Something to watch in the next few runs and hope that it is a shallower feature.

As @Man With Beard has suggested most of the eps have the runner much shallower and further south.  This is the evolution I would favour for now...

[Rollo]

44 minutes ago, offerman said:

Absolutely spot on. Great post. The charts chop and change and no one but no one can get it right its as you say guesswork.

I would think it would be better not to criticise those who attempt some sort of long range forecasts if you cannot proffer something sensible yourself.

[andymusic]

4 minutes ago, Rollo said:

I would think it would be better not to criticise those who attempt some sort of long range forecasts if you cannot proffer something sensible yourself.

fair point but logically looking at it anything past about 10 days is a bit like betting on the lottery, so these longer range forecasts are a little like shooting in the dark unfortunately, until such time as computers can do even more precise calculations to be able to correctly solve this further out, it'll continue like this

[Man With Beard]

35 minutes ago, andymusic said:

the low spinning through in the middle of next week could go further north or south, but generally speaking will offer wintry weather as well as possibly rain, but could also offer blizzards in places, and the other chart quite clearly displays coverage of snow over the UK for the benefit of people who keep saying there won't be any lol

I'm watching that T132 storm closely this afternoon. Some of the GFS 06Z members were 1987 style. What bothers me is that they were freakishly like the offerings of the ECM a couple of days ago, when these things come and go in the models, there's clearly potential for something big. I'd love a snowstorm but only if the electric is still working to keep my home warm!!

[OfficialKevWX]

Southwards corrections soon on that 06z low  ?

Edited January 12, 2018 by OfficialKevWX

[karyo]

2 minutes ago, Man With Beard said:

I'm watching that T132 storm closely this afternoon. Some of the GFS 06Z members were 1987 style. What bothers me is that they were freakishly like the offerings of the ECM a couple of days ago, when these things come and go in the models, there's clearly potential for something big. I'd love a snowstorm but only if the electric is still working to keep my home warm!!

If it could be a guaranteed snowstorm I'd say let it happen! My worry is the deeper the low gets the more chance to be rain as it sucks in milder air from the south.

The 0z ICON also had this deep low tracking through the UK so I am interested to see what this run does.

[sausage]

for us northerners we'd prefer a deeper feature. cant take another hit to the midlands missing everywhere else!! again.

[johnholmes]

Not sure if this is the place so mods please move in not, latest UK Met model for remainder of winter.and into spring

Briefly looks to me like slightly above average rainfall and similarly with the 2m temperature?

https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

[karlos1983]

2 minutes ago, johnholmes said:

Not sure if this is the place so mods please move in not, latest UK Met model for remainder of winter.and into spring

Briefly looks to me like slightly above average rainfall and similarly with the 2m temperature?

https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

That seems pretty useless to me doing it over a 3 month period? Could have 1 very cold month and 2 warm months. Guess it’s more useful for plotting against climate average.

[andymusic]

3 minutes ago, karlos1983 said:

That seems pretty useless to me doing it over a 3 month period? Could have 1 very cold month and 2 warm months. Guess it’s more useful for plotting against climate average.

again a complete guessing game for long period future forecasting when they change there 30 dayer every other day, let's get that right 1st eh