Model output discussion 02/02/20

[Jeremy Shockey]

GFS 12z @ t108

Uppers @ t108

GEFS 12z ensembles

Surely some good probability of snow showers starting at t108 ( for a couple of days ) with decent uppers. Elevation probably required so i will be heading to the Yorkshire hills in my location , but chances exist above 200 m across the country i would expect. 

 

Edited February 6, 2020 by Jeremy Shockey

[nick sussex]

Looking at the ECM ensemble spreads .

That suggests that some solutions are more amplified than the op. Some take the low situated to the west of the UK at day 6  se into northern France .

In terms of the transition from the PM flow to when the PV reforms is still subject to change . The pattern over the USA and Canada involves several shortwaves , with also phasing issues .

This is what’s causing the divergence between the models in the medium term because of the knock on effects downstream .

Its very unlikely these differences though will lead to a reprieve from the PV . That signal seems very strong but we live in hope.

 

Edited February 6, 2020 by nick sussex

[Man With Beard]

A note on the winds for Sunday - most main models bring 70mph gusts to many places far inland, and even 80mph in spots. ECM and GFS are pretty much on the same page. 

Is it too late for a late developing disturbance in the flow, blowing up into a small low pressure system? I still don't see why it couldn't happen. If it did, winds could locally go even higher - and of course, anything higher than 80mph and serious problems are possible. 

[Dean E]

31 minutes ago, Man With Beard said:

A note on the winds for Sunday - most main models bring 70mph gusts to many places far inland, and even 80mph in spots. ECM and GFS are pretty much on the same page. 

Is it too late for a late developing disturbance in the flow, blowing up into a small low pressure system? I still don't see why it couldn't happen. If it did, winds could locally go even higher - and of course, anything higher than 80mph and serious problems are possible. 

I think that could be possible, but from current output, looks unlikely.

What is interesting is there are 11/20 runs of the 12z GFS going for a central pressure of 950mb at 12pm Sunday. 9/20 are going for 945mb, which would mean stronger pressure gradients and thus stronger wind gusts.

18z will provide more clarification, but so far, the exact strength still is uncertain. 

[IDO]

My area, the south looks most at risk Sunday morning & afternoon:

Some extreme rainfall totals for the NW Sunday accompanying that storm:

Maybe back-edge snow before battered by snow showers in the west, maybe pushing inland?

A day to stay indoors I think.

[Ross90]

Everywhere except the central belt get something interesting on the latest run, no gusts above 50 mph here apparently...

[IDO]

...windchill Sunday into Monday:

 

[SMU]

GFS 18z sharpening up that low at 138 even more - thats going to cut SE across the UK

[Eskimo]

Low more negatively tilted and slightly further south. Could be bucking a trend to send it sliding with frontal snow but not on this occasion. 


 

Edited February 6, 2020 by PerfectStorm

[IDO]

Third run in the row where GFS op avoids the ECM 12z solution:

GFS>ECM>

See which model is correct tomorrow?

[nick sussex]

It’s a shame the upstream troughing is so broad and couldn’t just sharpen up a bit at T144 hrs  as that would send the low sliding se wards .

The GFS is refusing to back the ECM and is intent later on having the jet further south .

The 18 hrs even manages to hold onto some weak heights over south and eastern Greenland here .

[Gowon]

27 minutes ago, IDO said:

...windchill Sunday into Monday:

 

That's for Monday into Tuesday 

[Johnp]

Is the lack of posts regarding FI out of sheer disbelief?

[Eskimo]

3 minutes ago, Johnp said:

Is the lack of posts regarding FI out of sheer disbelief?

Even the donkey with the carrot dangled in front of him will grow tired eventually. 

[Ravelin]

Well if nobody else is going to, I'll post a frame. Vortex gone missing... 

Slider incoming? 

[markw2680]

It’s because everyone has been watching love island lol, Nar just been a tiring winter of let downs so far so just waiting for this storm to come and then maybe get some white surprises if we are lucky, you never no we may get some decent upgrades in the coming days regarding next week, then again we may not

[nick sussex]

Putting aside the normal vaguaries of post day ten GFS outputs even earlier this looks an unlikely scenario .

The main chunk of the PV displacing that far to the nw and those weak heights hanging on to the north .

Anyway we’ll see in the morning if this is another wild goose chase to add to the ECMs one earlier today .

[Tim Bland]

[Ravelin]

10 minutes ago, nick sussex said:

Putting aside the normal vaguaries of post day ten GFS outputs even earlier this looks an unlikely scenario .

The main chunk of the PV displacing that far to the nw and those weak heights hanging on to the north .

Anyway we’ll see in the morning if this is another wild goose chase to add to the ECMs one earlier today .

Almost certainly a cold outlier, extremely unlikely to verify, but we can but hope. Surely after months of dross we're owed a northern hemesperic picture that looks like this... 

[Allseasons-Si]

What a chart this is.....

but at 16 days away we can only dream at this,but nice viewing never the less

as for the mjo,it is still showing the amplified solution into phase 7 and it will be interesting to see where we go from here

and as for the strat at 10hpa there is a huge uptick now

today's v's two days ago,will it carry on with this,we will find out tomorrow

there is lots going on this weekend into next with everything including the kitchen sink thrown in,be it strong winds,hail,thunder,rain,sleet and snow showers

buckle up peeps,its going to be a bumpy ride and i would give credit to the pilots in that lot next week,good luck

at least there is something to talk about weather wise but also i do wish everyone to stay safe and do not underestimate the power of nature.

Edited February 6, 2020 by Allseasons-si

[Allseasons-Si]

Erm!!!

that's a better set of gefs ens from the 18z

18z tonight v's 18z last night

most of the mild solutions are cancelled,ok not breath taking cold but a step in the right direction

[Eskimo]

3 minutes ago, Allseasons-si said:

Erm!!!

that's a better set of gefs ens from the 18z

18z tonight v's 18z last night

most of the mild solutions are cancelled,ok not breath taking cold but a step in the right direction

If the ens can flip that much then I would fully expect them to flip the other way just as easily on the next run. 

Edited February 6, 2020 by PerfectStorm

[Allseasons-Si]

1 minute ago, PerfectStorm said:

If the ens can flop that much then I would fully expect them to flop the other way just as easily on the next run. 

You are quiet right but don't shoot the messenger

i am just posting what they show in comparison of which it can be noteworthy,lets just wait and see if this a new trend in subsequent runs.

[Cheshire Freeze]

21 minutes ago, PerfectStorm said:

If the ens can flip that much then I would fully expect them to flip the other way just as easily on the next run. 

I've always said that the ensembles are almost as useless as the operationals in providing clarity at times.

[Daniel*]

I’ve never known such huge difference between American and euro the former wants a taste of winter the latter wants a taste of spring. The 18z GEFS also a large swing to retaining cooler conditions. Maybe this vortex could be under more hot water than anticipated? With MJO if right seems too early for impact.

london 18z > 12z