Model output discussion - into 2018

[summer blizzard]

13 minutes ago, Paul Sherman said:

Oh you reckon ?

Lol you really need to look back at events before making such bold statements.

34cm of Level snow from 46 hours of continuous snow with -10 uppers and 1010 500mb heights

1010mb is pretty low, lower than average infact. I think the valid concern is that outside the south east corner, most places look like seeing 1030mb pressure values or such and that will mean that they will struggle to see significant shower potential. 

[shotski]

5 minutes ago, ShortWaveHell said:

Look at Siberia/ Russia in contrast ! Let’s tap into some of that 

Pretty much rolls reversed of what we have at present. 

[Paul Sherman]

It is a brave man who calls an Easterly even 24 hours before I reckon.

ANyway back to the Models.

Will GFS move towards the Others more on the 18z run, I doubt it

[Lowestoft Weather]

Certainly looking chilly over the coming week. Temperature's then recover to near normal with a nice southerly developing in a weeks time. Temperature's in doubles digits across the south. 

 

[Nick F]

17 minutes ago, Weather toad said:

Considering what they have at the moment, that is an amazing temp anomaly for the states. 

The medium to long range operational output and ens guidance has been hinting at the de-amplification of the upper trough and retreat back north of the deep cold over eastern N America, this cold has dug so far south it's brought snow to northern Florida today.

The reason for warm up is development of an Aleutian low replacing the -EPO ridge which will flood N America with milder Pacific air, this trough anomaly eventually shifting east towards western N America in the means meaning a warm up in the east of NAM mid-month onwards. This could be tied in with lag effect of phase 3 of MJO wave.

Be interesting, if this does occur, what effects it may have downstream, the GFS operationals, and GEFS/EPS means want to remove the block return us to a +NAO regime in response to the pattern change upstream, but if the block is underestimated by model guidance, we could see the energy continue to divert around the block. It could be a case that the pattern changes upstream over the Pacific and N America may not mean changes downstream over Europe, because of the block's stubborness.

Edited January 3, 2018 by Nick F

[feb1991blizzard]

Just now, summer blizzard said:

1010mb is pretty low, lower than average infact. I think the valid concern is that outside the south east corner, most places look like seeing 1030mb pressure values or such and that will mean that they will struggle to see significant shower potential. 

I want talking surface anyway - if you've got insanely low uppers / 500mb heights, you can afford at least 1020mb of pressure - possibly pushing 1030mb - look at Jan 87, ok the North didn't get as much as the SE but there was still some pastings and that was high surface but really low heights / thicknesses etc.

[Paul Sherman]

1 minute ago, feb1991blizzard said:

I want talking surface anyway - if you've got insanely low uppers / 500mb heights, you can afford at least 1020mb of pressure - possibly pushing 1030mb - look at Jan 87, ok the North didn't get as much as the SE but there was still some pastings and that was high surface but really low heights / thicknesses etc.

Yh just looked at that actually, quite surprised that all the main events on the archive are between 1010 and 1030.

[northwestsnow]

2 minutes ago, Lowestoft Tiler said:

Certainly looking chilly over the coming week. Temperature's then recover to near normal with a nice southerly developing in a weeks time. Temperature's in doubles digits across the south. 

 

Any particular reason your quoting GFS?

Just curious.

[Man With Beard]

VERY interesting looking at the air temperatures on the ECM ensembles towards the end of the run.

By T192, lots of low single digit maxima and a few places with ice days.

By T240 it's colder still. About 50% of runs have ice days for some places and 20% of runs have ice days for most places. The mean chart might make you think it's getting milder but not the case except for a few members. 

By T288 it's generally getting milder with most runs at least in low single digits (some back to 10C-15C) but still a few keep going with ice days in places - and one or two really insanely cold runs for the north.

Not a great amount of snow around though, except when there are Atlantic battlegrounds. Bizarrely the south coast looks the most favoured for a dusting on some runs what with the cold SEly

[northwestsnow]

5 minutes ago, feb1991blizzard said:

I want talking surface anyway - if you've got insanely low uppers / 500mb heights, you can afford at least 1020mb of pressure - possibly pushing 1030mb - look at Jan 87, ok the North didn't get as much as the SE but there was still some pastings and that was high surface but really low heights / thicknesses etc.

Excellent post Feb

[Dancerwithwings]

1 minute ago, Lowestoft Tiler said:

Certainly looking chilly over the coming week. Temperature's then recover to near normal with a nice southerly developing in a weeks time. Temperature's in doubles digits across the south. 

 

Hah! your have it wrong.....that's tomorrow!!!

[I remember Atlantic 252]

6 minutes ago, northwestsnow said:

Any particular reason your quoting GFS?

Just curious.

maybe because of his job? username maybe

[snowbob]

23 minutes ago, Weather toad said:

Considering what they have at the moment, that is an amazing temp anomaly for the states. 

Think it was the famous Ian mc caskill famous 91 forecast that said record breaking warmth over the pond 

just saying that if they get warm there we have had a great cold spell this time of year

prob completely wrong but that just sticks in my mind

[lorenzo]

There was a cool table kicking around a couple of yrs back that illustrated the variance from pressure to 850hPa temps - this provided a lens on what 'could' be expected. Sorry - boring I know - data loss - hopefully a hard core netweatherer can dig it out, had a dutch heading..

[shotski]

Just now, snowbob said:

Think it was the famous Ian mc caskill famous 91 forecast that said record breaking warmth over the pond 

just saying that if they get warm there we have had a great cold spell this time of year

prob completely wrong but that just sticks in my mind

I think your absolutely spot on. 

I remember watching that forecast on YouTube. 

[Paul_1978]

2 minutes ago, snowbob said:

Think it was the famous Ian mc caskill famous 91 forecast that said record breaking warmth over the pond 

just saying that if they get warm there we have had a great cold spell this time of year

prob completely wrong but that just sticks in my mind

You’re spot on. This one:

 

[Daniel*]

Day 9 on ECM pretty sure there would be a fair bit of convective snow showers for the S/E nothing exceptional lower 500mb heights courtesy of upper trough moving in? Uppers sufficient for convection. 

[Ali1977]

If we could only start this cold spell off with a decent snow event, areas with lying snow in this set up in Jan would surely see some -teen temps

Edited January 3, 2018 by Ali1977

[Snowman.]

2 minutes ago, Daniel* said:

Day 9 on ECM pretty sure there would be a fair bit of convective snow showers for the S/E nothing exceptional lower 500mb heights courtesy of upper trough moving in? Uppers sufficient for convection. 

Someone posted a picture a page back or so with a band of snow over the SE.

[bluearmy]

21 minutes ago, The Enforcer said:

Could anyone post a similar comparison for the last four ECM 12z for next Tuesday?

[Daniel*]

Just now, SN0WM4N said:

Someone posted a picture a page back or so with a band of snow over the SE.

Hm there could be something more organised moving in - interesting but too far out for too much detail. From Saturday there looks to be some North Sea convection north of Humber could be decent ish.

[Sweatyman]

20 minutes ago, Lowestoft Tiler said:

Certainly looking chilly over the coming week. Temperature's then recover to near normal with a nice southerly developing in a weeks time. Temperature's in doubles digits across the south. 

 

What's this rubbish? Double figures!!

[Snowman.]

4 minutes ago, Daniel* said:

Hm there could be something more organised moving in - interesting but too far out for too much detail. From Saturday there looks to be some North Sea convection north of Humber could be decent ish.

[SMU]

ECM 15 day T2Ms best yet ....

Expecting the GFs 18z to continue its move...

 

[sparky1972]

17 minutes ago, northwestsnow said:

Any particular reason your quoting GFS?

Just curious.

hi, to be fair the forecast i looked at said the same but i noticed on the weatheroutlook.com they use the GFS and for us here in sth Lincs they have temps of 8c for the middle of next week.