Model output discussion - the beast arrives

[Captain Shortwave]

Now this would be interesting

   

The low stalls and simply crawls along the English channel, with cold air still in place further  north there could be a lot of snow for the Midlands and southern Engalnd in particular, the north remains very cold and showery.

GFS/GEM not so hot 

   

Both would take the front north and leave the south probably still feeling very raw, any areas with substantial snow cover would likely remain very cold under an inversion will lots of low cloud.

Edited February 25, 2018 by Captain Shortwave

[ScottishSnowStorm]

UKMO 144hr chart looks really good 

[metaltron]

The models are all over the shop with this low approaching from the south - the GFS has a stronger low than on its 6z run whereas the UKMO shifts the low south when compared to it's 12z run yesterday. We could play "pin the tail on Bertha" again, but I fear emotions would be too high in the winter! Imagine handing out the prize to the person who predicted the low would be over Scotland on Friday!

[terrier]

Great looking ukmo this evening. Certainly looks to my untrained eye that it’s prolonging the cold. 

[Youcan'tbecirrus]

6 minutes ago, Steve Murr said:

5❄️❄️❄️❄️❄️

from UKMO 120

blizzards ! no rain anywhere

Steve what are your thoughts on any milder air being suppressed by surface cold where there is lying snow. Is this something that the models factor in ?  

[Eskimo]

Actually a worse run for the south. A brief spell of very heavy snowfall, possible blizzard conditions before warming up and turning back to rain. 

[radiohead]

2 minutes ago, That ECM said:

Steve, please explain why there would be no rain anywhere. Genuine question.

Looks like starting as snow everywhere then turning to snow for the majority with freezing rain in the far south.

[inghams85]

1 minute ago, Captain Shortwave said:

Now this would be interesting

   

The low stalls and simply crawls along the English channel, with cold air still in place further  north there could be a lot of snow for the Midlands and southern Engalnd in particular, the north remains very cold and showery.

MOGREPS mate. The next low filled behind and keeps us in Easterlies hence the text updates

[ukpaul]

Interesting to see GFS and UKMO having the low drift westwards, that keeps lower uppers over more of England and buries Ireland! With GFS starting that from a more northerly position and the UKMO further south it doesn’t appear to give a particularly different outcome. Because of the way the system interacts with or disengages from the jet?

Edited February 25, 2018 by ukpaul

[parrotingfantasist]

Just now, inghams85 said:

MOGREPS mate. The next low filled behind and keeps us in Easterlies hence the text updates

Somebody needs to tell the MetOffice about you and your leaks!!

[AmershamMike]

1 minute ago, inghams85 said:

MOGREPS mate. The next low filled behind and keeps us in Easterlies hence the text updates

What text updates?

[Derecho]

The UKMO at T144 shows exactly how I'd like Friday's low to play it, with trough disruption causing it to stall in the channel. Some huge snow amounts from that, being picky though maybe uppers could be a degree or two lower down here. We are in continental air still though the uppers at T120 creep above freezing, threat of freezing rain for us there... before turning back to snow 

[inghams85]

1 minute ago, AmershamMike said:

What text updates?

Long range on website

[Weathizard]

10 minutes ago, Steve Murr said:

5❄️❄️❄️❄️❄️

from UKMO 120

blizzards ! no rain anywhere

Even with barely negative uppers?

[Rayth]

2 minutes ago, parrotingfantasist said:

Somebody needs to tell the MetOffice about you and your leaks!!

Somebody needs to edit their post !! Explosive cyclogenisis fast !!!! 

[Singularity]

  

Well then. That's quite some difference in LP placement and elongation at just +96 between GFS (left) and UKMO (middle) + ICON (right).

GFS perhaps with typical dartboard low tendencies showing their hand, while UKMO has moved toward ICON's recent solutions.

  

GFS (left) a total facepalm by +120, UKMO (middle) far from it with some nice elongation eastward to keep the cold easterly flow in place across all areas (the cold/less cold boundary will be aligned to run through the pointy parts of the trough). ICON (right) remains the best of the three at that particular point in time though, with the weakest and flattest LP system.

ICON does then have a whole bunch of small lows complicating matters but the shunting east of the milder air helps to keep things on the cold side. A gradual thaw during the weekend I should think? Not great but closer to it than GFS by a long shot.

Ah hello there +144 UKMO, how very nice to see you - that's in line with the ICON 00z. The split away of the LP from the parent trough with subsequent track along the Channel is just what we need to keep the cold in place for all through at least Saturday.

The thrill of the chase 

[rory o gorman]

Good to see the UKMO following a certain private UK model, and yes I know people before you ask  

[Optimus Prime]

1 minute ago, Weathizard said:

Even with barely negative uppers?

What is it with people's obsession with that temperature profile? It's been said so many times before that we shouldn't rely too much on those temperatures for predicting snowfall. 

[tight isobar]

The LPS-latter nxt week is clearly modeled non-exact!!

Although shows a pivot-and effect..

And cuts into the progressive scenario.

And amps the flow for a continuation of fridged air!!!

Breakdown??? What breakdown!??

[SMU]

2 minutes ago, Weathizard said:

Even with barely negative uppers?

Just seen that-

Just the south / south coast although that gets mixed out quicker by 144-

Much much better UKMO this afternoon-

[mb018538]

For the last time....you can get snowfall without -10 uppers! They can be around zero with the right setup - such as what we have.

[That ECM]

Summer sun posting ukmo t168 will be worth a view. Hoping to see the back end of the low on the far right and basically out of view

[January Snowstorm]

Well if the models this evening play out anyway like they suggest southern Ireland will have to completely shut down for 2/3 days.

Jokes aside this could become very serious with even front line hospitals out of action

[radiohead]

12Z cranks the low up to 960mb. Some serious blizzard conditions for a time in parts of Ireland before a transition to rain. I think the GFS is overdoing the low this time though...

[Jason M]

7 minutes ago, That ECM said:

Steve, please explain why there would be no rain anywhere. Genuine question.

Something doesn't look right about that chart. Clearly, with those uppers its 'wet wet wet' rather than 'snow patrol' in the South , but looking at the 500 chart I'm really surprised to see the milder air that far north!!