Model Output Discussion - the cold has arrived

[LetItSnow!]

GFS 0z looking a lot different. The ridge in the Atlantic is far weaker which allows the two lows to link up. Also, the shape of the low is much different. It's setting up a southwesterly pattern. Not looking as good for coldies on this one so far to my relatively untrained eyes.

 

 

Edited December 15, 2022 by LetItSnow!

[Mucka]

Both GFS and UKMO stall the low just W of Scotland so greatly delaying any potential Northerly.

However there is some pretty decent blocking, especially UKMO, if we can convert the W based -NAO into a cold Northerly surge later.

Headline is poor Op runs so far for cold with neither UKMO or GFS bringing a Northerly and cold air over the UK

Edited December 15, 2022 by Mucka

[Cheshire Freeze]

GFS swings the Arctic HP round to Siberia and tries to help force an E'ly (I think this may be the long term end point), something that the like of Chiono have pointed out as a possibility.

If it got to that point and that strat didn't fall shortly after, nothing will give us a SSW this year!

[Mucka]

Some good news.

GFS ensembles predominantly push the low through and bring the Northerly

GFS mean

GFS Op

[LetItSnow!]

In the short term, a swing back to mild on the GFS 0z. Because the low is centred further west and the mid-Atlantic ridge is weaker it allows for a mild W/SW flow with plenty in the way of wind and rain. At day 10 which so happens to be the big day we get the low weakening over us as it crosses west to east and does allow a cooler interlude.

 

Not the movement I wanted to see but we press on for the next runs! And as stated above, the idea to bring in the northerly is still on the cards. Just because the 0z says no doesn't mean it won't happen of course (trying not to upset the coldies... AKA myself!!! ).

 

[Lukesluckybunch]

Not so much good output this morning..the euro heights make a return with the northerly never getting going..let's see what the ECM can deliver

[chicken soup]

6 hours ago, Allseasons-si said:

Boxing day battleground anyone,...bring it forward a day

That would be a carbon copy of Feb 1996..my fav ever snow event..I've been waiting since then for a repeat.

[Chesil View]

11 minutes ago, Lukesluckybunch said:

Not so much good output this morning..the euro heights make a return with the northerly never getting going..let's see what the ECM can deliver

Big swings in the medium term output much as Nick F and Matty H suggested last night. 

[feb1991blizzard]

52 minutes ago, CreweCold said:

GFS swings the Arctic HP round to Siberia and tries to help force an E'ly (I think this may be the long term end point), something that the like of Chiono have pointed out as a possibility.

If it got to that point and that strat didn't fall shortly after, nothing will give us a SSW this year!

With that chart, i would still like to see a pacific ridge, never fear about all the vortex being over Greenland and Canada though, as long as by the time the SSW occurs, there's enough frigid air on the siberian sector, the most impactful SSW's do occur with what look like zonal charts at the time - reasonable analogues for that chart - 09 and 91.

Edited December 15, 2022 by feb1991blizzard

[lassie23]

I wouldn't worry about less cold runs this morning, we have been here before, with a huge turnaround by the evening and vice versa, day in day out.

[feb1991blizzard]

2 minutes ago, lassie23 said:

I wouldn't worry about less cold runs this morning, we have been here before, with a huge turnaround by the evening and vice versa, day in day out.

Getting a bit close to the event now though - can't afford any more downgrades if we want snow in the short term.

[lassie23]

2 minutes ago, feb1991blizzard said:

Getting a bit close to the event now though - can't afford any more downgrades if we want snow in the short term.

I would take snow on New Year's Day rather than Christmas, because January is utterly depressing, especially when all the decorations come down and we all return to work in 13c  temps and rain. Snow would brighten things up a bit lol.

[nick sussex]

After last nights more positive developments for coldies it’s back down to earth with the models so far failing to clear the low east quickly enough and this phasing with upstream energy .

The issue really isn’t just the phasing if this was much further south it wouldn’t be such a problem .

The escape of heights west really does the damage . Anyway let’s hope the ECM can stop the slide .

[chris55]

Lots of scatter on the ensembles.

Op on the less cold side for London 

[That ECM]

13 minutes ago, chris55 said:

Lots of scatter on the ensembles.

Op on the less cold side for London 

I was just looking at the op and the control and not getting into which is right I would urge newbies to run the sequence and see why and where the difference is.  Kind of helps understand the current uncertainty.
 

ecm is encouraging at T120.

Edited December 15, 2022 by That ECM

[nick sussex]

The ECM day 5 looks better than the GFS.

A more ne flow to the north rather than the more east ne  with better heights in the key area .

We want to see more forcing from the nw rather than the north given the set up.

Edited December 15, 2022 by nick sussex

[Lukesluckybunch]

Ecm looking ok here at 120

[That ECM]

T144 all 3. Clear as mud.

[Lukesluckybunch]

5 minutes ago, nick sussex said:

The ECM day 5 looks better than the GFS.

A more ne flow to the north rather than the more east ne  with better heights in the key area .

We want to see more forcing from the nw rather than the north given the set up.

Is that so the trough..can drop down smoothly with no fuss?

[nick sussex]

In typical model fashion the ECM which was least interested in a colder post mild blip evolution now has the better day 6 chart .

No phasing so far .

We just need enough forcing day 6 into 7 to get the UK low further to the se as we are at this point likely to see some phasing as some shortwave energy upstream is likely to disrupt further east .

Okay at day 7 , heights hanging on for dear life to the nw .

 

Edited December 15, 2022 by nick sussex

[Lukesluckybunch]

At 168 in ecm..it looks to be just a glancing blow,as I fear by 192 the Azores high will be nudging in..there also appears to be a lack.of cold air around us..it's all bottled up to northwest!

Edited December 15, 2022 by Lukesluckybunch
Adding

[sheikhy]

Dunno why everyone falls for the 18z rubbish lol!!!you all know the 00zs as always bring us back down to earth!!story of the last number of years!-7 here at the moment!on to the 06zs!!

Its been freezing cold for days!!how this cold air just gets shoved away on sunday so easily without a fight is beyond me!!crazy times!!!

Edited December 15, 2022 by sheikhy

[That ECM]

See you at the 12z’s

[Lukesluckybunch]

Just now, That ECM said:

See you at the 12z’s

It's quite a decent run..give it 7/10

[That ECM]

9 minutes ago, Lukesluckybunch said:

It's quite a decent run..give it 7/10

If ecm is right then yes, IF.

It is easy to forget because there has been two gfs and Ukmo run between the last two ecm runs but it is consistent with its thinking which is a novelty at the moment. 

Edited December 15, 2022 by That ECM