Model Output Discussion - Snow for some, but what else is in store?

[Mark wheeler]

19 minutes ago, Kentspur said:

Interesting to see if UKV sticks to showing sleet and snow over virtutally the entire SE 1/3 of the country as this morning it consistently forecast rain/sleet only for a number of places (blue shades) which proved right its my go to model now along with Icon 

Oh no not again, saw a few flakes this morning amongst the rain  , Hooray , Anyway here is the Mighty Navgem this evening at 156 hrs . No good for us mate but some will profit from this . 

 

[Chiltern_Blizzard]

1 hour ago, chris55 said:

Its in my diary lol...... Snow event for the middle section of the UK next weekend. It'll be news worthy.

Im expecting snowman pics from Cheltenham, Swindon, Hereford, Oxford, MiltonKeynes as a guide  

Praying!

[markw2680]

What we have to remember here is that just a very small change early on in the run can make massive differences later on, especially atm. Things are more volatile than usual. I personally think there will be some big swings in the output over the next couple of days. Nothing is nailed atm. I wouldn’t wana be doing the country file forcast tomorrow that’s for sure. Keep the faith people there changes afoot 

[danthetan]

34 minutes ago, Don said:

As I alluded to earlier, if we didn't have those pesky heights to the south, the outlook would be pretty good with more southerly tracking lows!

This all hinges on enough forcing by the Greenland high south to stop the low pressures heading north getting caught up in the easterly flow and blowing up allowing the azores to ridge north and putting the UK in a SW/W flow. corrections south is crucial here and has been the general direction last few runs. 

[Geordiesnow]

I see comments it's the UKMO vs the rest but I don't see it that way, all the models look pretty similar too me and its just the details which of course can make a huge difference. 

People also mentioning its weird why the low is deepening that much but it makes sence as there is mild air and cold air clashing into the same system so makes it more unstable and deepens it. Probably other factors also so its not a certainty the low will actually deepen and in theory this may increase any snow risk there might be. Either way, the ideal set up would be that low to head as far east ass possible which allows more colder air to filter in from the north, if the centre of the low is too close and its too deep, less cold air will filter in. 

Its going to be a tough week getting the details right but the rainfall risk does look more of a concern than snowfall at this stage. 

[Don]

10 minutes ago, Geordiesnow said:

Its going to be a tough week getting the details right but the rainfall risk does look more of a concern than snowfall at this stage. 

The Metoffice now have yellow warnings for rain covering Wales and North West England from Monday to Wednesday.

[Cryosphere.]

And the winner of the most excellent award of being most excellent...goes too..."Homer simpson!"  These models are...at best  ..say no more..

 

[icykev]

GFS looks like the ridge may hold at +72 

 

[Summerstorm]

11 minutes ago, icykev said:

GFS looks like the ridge may hold at +72 

 

We aren't focused on that part of the run what we are focused on is the 120/144hr time mark what we are looking for is for the two lows not to phase and to avoid any shortwaves from the Eastern US and Scandi Low's. Therefore we maintain a better Atlantic Ridge this means that the Greenland high is stronger and thus hopefully pushes the pattern further south allowing cooler northerly air to drop down behind it. 

Otherwise if we don't maintain that high or it doesn't get reinforced by the artic high then the jet stream gets forced further north again and we end up in a SW air stream as a consequence as the Azores High starts ridging into Iberia again. 

 

 

Edited January 17, 2021 by Summerstorm

[Battleground Snow]

UKMO sticking to its guns at 144

Edit: GFS at the same time.

 

Edited January 17, 2021 by Battleground Snow

[icykev]

Still holding @126 and further east, looks like its trying to link up with artic heights

[Summerstorm]

20 minutes ago, Battleground Snow said:

UKMO sticking to its guns at 144

Edit: GFS at the same time.

 

GFS not quite as good as the UKMO, looks good at 120 like the UKMO but then blows the low up and elongates the low in the mid Atlantic. Although it does have that similar little low over Italy which may become helpful if that strengthens to keep the AH out of Southern Europe. 

It does drop the cooler air around +144 but the AH ridging back into S Europe stops the low from sinking and introduces milder air. 

One thing to notice is can we eek out any extra amplification at +120 as seen on both runs to help us especially without blowing up that low pressure to the east of us and whether we can get a favourable angle from the low exiting the US to get some WAA to assist the Atlantic Ridge.

 

Secondly the GFS P looks better doesn't blow that low up and in turn keeps some of the cooler -6 air in and brings in a nice slider around Day 7 although feels academic at that stage. 

In my opinion follow the OP GFS up to 120/144 hrs then follow the Parallel from there. 

Edited January 17, 2021 by Summerstorm

[Battleground Snow]

Para has the jet stream ever so slightly further south at 174.

 

[northwestsnow]

Ukmo 144...

Only going one way I would say.

That ruddy Azores high waiting to ruin things...

[northwestsnow]

GFS 0Z para is better at 144...

 

And there is a snow event shortly after across the south..

[northwestsnow]

EC 144.

[northwestsnow]

168 ..

[Battleground Snow]

1 minute ago, northwestsnow said:

168 ..

Interesting, defo no Azores high there, 850mb temps are okay. Would be good if that weak amplification in the Atlantic could gain traction

[Battleground Snow]

GEFS 00z v 18z

Mild temps squeezed out

[northwestsnow]

Well well well ECM...

Having second thoughts?

Certainly a colder 00z run than yesterday's offerings...

[Battleground Snow]

An improvement on the ECM in terms of cold over the UK. 

 

[Battleground Snow]

Just now, northwestsnow said:

Well well well ECM...

Having second thoughts?

Certainly a colder 00z run than yesterday's offerings...

It's very quiet this morning NWS, hopefully this will please people when they wake up.

Very volatile models still, keeps me coming back for more.

[KTtom]

Well if you love your weather, it probably doesn't get any more interesting than this. Persistent, heavy rain leading to flooding for the first half of the week (not sure how anyone could like that though!),  Gales and showery second half with everything including the kitchen sink thrown in, and then significant snow prospects over the weekend depending on the track of the lows...this I feel is going to cause severe stress in here over the week as models chop and change the trajectory of these systems. Still, if your stuck indoors, it'll keep us entertained

Edited January 17, 2021 by KTtom

[northwestsnow]

Yes a much better EC with colder air persisting until day 9..

Perhaps the first hints the local forecast is picking up on colder weather from thurs with mention of cold with wintry showers ....

Certainly a snowy outlook at altitude locally if we can get the precip...

[Daniel*]

Clear to see odd one out.