Model Output Discussion - 05/01/2016 18z onwards

[bobbydog]

 

35 minutes ago, Ali1977 said:

Timings may be critical, temps will quickly fall after dark so as long as precip coincides with this , we may have a chance.

if the ECM has this spot on, timings would be almost perfect. 850 temps -6c to -7c across virtually the whole country by friday evening-

(thats 0100 friday morning)

precipitation forecast-

 

(courtesy of Iceland M.O. via ECMWF)

so would likely fall as snow after dark,

Edited January 10, 2016 by bobbydog
to correct schoolboy error!!

[radiohead]

3 minutes ago, bobbydog said:

 

if the ECM has this spot on, timings would be almost perfect. 850 temps -6c to -7c across virtually the whole country by friday evening-

(thats 0100 friday morning)

plenty of precipitation forecast-

(courtesy of Iceland M.O. via ECMWF)

so would likely fall as snow after dark, possibly everywhere

That is the 100m wind chart though, precipitation chart for that time is here :

[Hull snow]

5 hours ago, KasimWeatherQuarnford said:

Not trying to hype, and a fairly uncertain progression however the GEM is fairly concerning for my part of the Pennines and much of the Pennines.

 

UKMO pushes the worst of it back slightly but minimal next Thursday 

GFS good for snow v similar to 18Z but doing its usual thing with the Ott early breakdown 

 

ECM is now more than likely to go with UKMO and gem with the Greenland ridge 

such a good time to be having a slow upgrade, snow is now inevitable here but elsewhere ☂☃ the snow / rain boundary looks quite narrow on Thursday, looks like a real headache 

 

Why is gem concerning pal ?

[bobbydog]

1 minute ago, radiohead said:

That is the 100m wind chart though, precipitation chart for that time is here :

bugger, thats why it looked odd- clicked on wrong tab!

[Ali1977]

GFS stuck at T30....guess it's struggling to decide what's going on!!

[Geordiesnow]

Got to say, the initial blast of cold air is looking more and more sorry for itself, we were supposely to have -5 hpa trying to cover the country but it really is struggling so unfortunately, I do feel snowfall could well be a struggle. Hopefully heights will try and build again but I won't hold me breath. Its all a little bit slack and I don't see anything to extreme really to be fair at this moment in time. 

[Nouska]

5 minutes ago, radiohead said:

That is the 100m wind chart though, precipitation chart for that time is here :

Another wider view of forecast precip at 120 hours  

The freebie EPSgram today is for Reykjavik - quite some spread and early disagreement between Det and Control.

 

 

[Great Plum]

2 minutes ago, Ali1977 said:

GFS stuck at T30....guess it's struggling to decide what's going on!!

Certainly working on wetter...

[IDO]

6 minutes ago, bobbydog said:

 

if the ECM has this spot on, timings would be almost perfect. 850 temps -6c to -7c across virtually the whole country by friday evening-

(thats 0100 friday morning)

plenty of precipitation forecast-

(courtesy of Iceland M.O. via ECMWF)

so would likely fall as snow after dark, possibly everywhere

As above post that is wind. According to ECM and the T84 fax the occluded front arrives on early Thursday so time the very cold uppers move south that front has cleared. The GEFS for Thursday for London have been around 25% for a while now, so sea level in the south from current charts (useless really as even at T01 things can change) low probability but risk increasing with +ASL. I think that low coming in from Iceland is now very likely and the track suggests snow for the NW into the Midlands, the higher the better. 

This is all subject to change as the spin off Azores low could blow up and bring a milder sector into the south and this looks like it could clash with that Icelandic low. The GFS 06z:

That warms out the uppers and reduces the initial snow chances. We may not know for a few days...

[snowblizzard]

3 minutes ago, Great Plum said:

Certainly working on wetter...

We just can't get that clean Northerly flow.

Very frustrating!

Edited January 10, 2016 by snowblizzard

[Iceberg]

Another baby step from gfs 06z at t96 towards the euros re Greenland and n.atlantic energy. 

[shaky]

Gfs more amplified at 96 hours already compared to 00z run!!makes less of that shortwavee southern greenland!!

[kumquat]

Yes @Iceberg cleaner flow from NNW on gfs 6z.

Less impact from Icelandic shortwaves:

 

[Great Plum]

114 hrs is when practically the whole country is under -5 uppers...

[Polar Maritime]

GFS 6z shows colder 850's/Dp over the UK Thursday/Fri. Thanks to the Icelandic Low..

 

Edited January 10, 2016 by Polar Maritime

[Ice Day]

7 minutes ago, Iceberg said:

Another baby step from gfs 06z at t96 towards the euros re Greenland and n.atlantic energy. 

Agree, each of the last few runs the GFS has been inching towards the euros.  Colder uppers a little further south at 120hrs.

Details still sketchy, but a cold/very cold week coming up

[Ali1977]

Feature still showing for Fri evening to the SW, depending on the track and if it hits the cold air it still looks like that may deliver in places.

[IPredictASnowStorm]

    great from the gfs for snow here

Edited January 10, 2016 by IPredictASnowStorm

[Jason M]

53 minutes ago, Geordiesnow said:

Got to say, the initial blast of cold air is looking more and more sorry for itself, we were supposely to have -5 hpa trying to cover the country but it really is struggling so unfortunately, I do feel snowfall could well be a struggle. Hopefully heights will try and build again but I won't hold me breath. Its all a little bit slack and I don't see anything to extreme really to be fair at this moment in time. 

Tend to agree with this. Based on what we're seeing it seems to me like a rather cold week, with the risk of snow primarily in the north and on high ground. This episode reminds me of a similar sort of coldish spell about this time last year. We are really just struggling for scraps here. The core of the heights are principally to our south and southwest. As a rule of thumb (imho) if pressure remains relatively high over Iberia we will struggle to get deep cold into the uk. 

This GFS run is better and the trend is slightly better, but without proper heights to our north, forget deep cold. 

Imby, I wouldn't be surprised to see some snow falling at some point, but the snow gear is unlikely to be required. Just my opinion of course and I'm sure others have a different take :-)

Edited January 10, 2016 by Jason M

[Ali1977]

So, this cold spell is in the bag - snow possible at some point pretty much anywhere...although no probable. Continent now cooling down, let's hope if we get another cold spell later Jan/Feb it's from the east. 

[weather eater]

I have to say and unfortunately so, that I fail see where we are inching towards the Euros. The GFS appears to me to be showing remarkable consistency. Yes of course there is some variation but nothing you wouldn't see day to day any time of year. I suspect (though  hope I'm wrong) either this evening or by the morning we will see an about turn by the UKMO in particular and a shift towards the GFS by the ECM.

Edited January 10, 2016 by weather eater

[IDO]

The last 5-6 runs on the GFS op have had the 0c T850 hit London during the 17th to early 18th, very consistent, there has been no trend to increase the cold longevity. The 06z run is in tandem with the last couple of days. The only change is that the mean was out of kilt and has slowly moved towards that date as well.

Certainly no backtrack from GFS. At D7 (17th) :  

[Hull snow]

I still belive further upgrades to come to the ukmo which I belive could be correct and if so the charts from a few days ago wudnt be far away at all very good this morning folks 

[Polar Maritime]

The cold is stubborn to move East as the North Atlantic tries to make inroads from the N/W, We could very possibly see a mixing of cold pools over the UK as the Heights sink. But the N/W Pm flow seems to win eventually for now at least.

Edited January 10, 2016 by Polar Maritime

[Jayfromcardiff]

37 minutes ago, Geordiesnow said:

Got to say, the initial blast of cold air is looking more and more sorry for itself, we were supposely to have -5 hpa trying to cover the country but it really is struggling so unfortunately, I do feel snowfall could well be a struggle. Hopefully heights will try and build again but I won't hold me breath. Its all a little bit slack and I don't see anything to extreme really to be fair at this moment in time. 

Just had the heads up that a channel low is going to stall over Wales and the SW on Thursday leading to around a foot of snow - get them tractors out haha!

 

Jokes aside I have a gut feeling the gfs could be right on this occasion as its been consistent throughout. Hopefully not though as it'd be nice for everyone to get their snow fix!