Model Output Discussion - Winter arrives

[Hotspur62]

Wow what a day.Looked at models this morning before work and things were a bit downbeat but just got home and read through 6 pages(always a good sign cold weather may not be far away ) and some very interesting possibilities.Think Carinthian has it right-don’t look past +96hrs atm as a lot of volatility in the models.Favourite for me is as it was this morning with some cold shots on Nw Se axis and some mild shots(but not excessively mild like previous winters).Snow chances more for favoured northern parts of Britain but as yesterday proved things do and can pop at at very short notice

[Mucka]

Good evening fellow weather freaks,

There often seems to be a disconnect between what the models have shown and what people think they have shown over recent runs.

Below are the 00z output of GFS and ECM for 5th Dec with side by side from 27th Nov output and today's output for each model.

GFS Nov 27/29th output 00z for Dec 5th

ECM Nov 27/29th output for Dec 5th

and finally GFS 00z 27th output compared to todays ECM ooz output for Dec 5th

GFS forecast the positive height anomaly to the NE and blocking ridge with ensuing trough disruption/undercut and Atlantic ridge two days ago and ECM followed.

We need to not just take the output as it comes, but reference it against previous output to have a better idea of which way each model has trended and where we might go next. It is not a matter of better/worse as those margins are quite small and dependent on synoptic.

 

For an old dog like me this has a classic retro Winter feel. I did not expect this current spell to to provide lying snow on low ground through the day as the cold air never really gets established and there is plenty of mixing but we have seen very cold surface temps and hard frost and it is only Nov! That takes me back how a typical and common early Winter spell used to "feel."

 

Competing air masses with very early season deep cold becoming established to our East and North East and warmer Atlantic air wanting to charge across yet already struggling and being deflected SE/NE despite a fairly strong zonal signal.

That is encouraging and in basic terms means we are unlikely to get mild Westerly flow anytime soon so the question is really how far W the cold block can deflect the milder Atlantic air.

The forecast is generally staying unsettled and but for a blip tomorrow generally chilly with further rain/sleet/snow for some.

Anyone putting detail beyond that past 7 day range is on a hope and a prayer and the models won't be a great help. Posts on background signals may be more helpful if less fun.

I don't personally currently see a classic blocked pattern with potential for a retrograding Scandi high unless the Atlantic freight train slows or derails further W soon so mixed signals and mixed weather for the foreseeable with snow chances for some.

 

The forum should stay bubbling along with excited chatter rather than predictions of doom, but I guess doom is the current fashion.  (It is all good, ramps V grumpy pants, and keeps the place alive, not having a pop at anyone)

[Lukesluckybunch]

even as early as t96 im liking the look of ECM

[ICE COLD]

Nice GEM tonight. Hoping the ECM run goes the same way as it . Not long to wait

[TSNWK]

On 29/11/2021 at 18:15, Lukesluckybunch said:

even as early as t96 im liking the look of ECM

In traveling what you seeing?

[MATTWOLVES 3]

45 minutes ago, Climate Man said:

You see @MATTWOLVES, not all over yet. Were you playing mind games with the synoptics?

Monday morning blues mate....never say NEVER!

Big EC46 tonight.

Gem is a peach...let's do this.

[Ali1977]

WOW, this looks much better to our NE , this could be the best run yet of any model 

Edited November 29, 2021 by Ali1977

[sheikhy]

Ecm at 120 hours

[Battleground Snow]

Not sure where @Griff is today, but here is the comparison at 120. A clear odd one out 

[Cheshire Freeze]

On 29/11/2021 at 18:21, Ali1977 said:

WOW, this looks much better to our NE 

Higher amplitude Atlantic ridging too…possibly the most important thing.

[Mike Poole]

ECM T120 v GEM:

Similar, GEM slightly better heights to NE, worry that ECM will be too circular with the low off Canada and it might barrel through, we will see.  

[ICE COLD]

ECM looks good at T120 . That’s quite a nasty little low . Snow on the western flank ?? 

[clark3r]

ECM 120 to my untrained eye will not be cold enough for snow on the western plank, correct me if I am wrong 

[Ali1977]

2 minutes ago, ICE COLD said:

ECM looks good at T120 . That’s quite a nasty little low . Snow on the western flank ?? 

 

Maybe a little too warm 

[Mike Poole]

ECM T144, and we have the wedge.

Edit, help if I added the chart

Now this run looks good.  

Edited November 29, 2021 by Mike Poole

[ICE COLD]

1 minute ago, Ali1977 said:

 

Maybe a little too warm 

Plenty of time for upgrades

[winterof79]

Ooo look at that wedgy

Edited November 29, 2021 by winterof79

[Ali1977]

Looks good with a slider on its way 

[TSNWK]

144 

[Tim Bland]

5 minutes ago, ICE COLD said:

ECM looks good at T120 . That’s quite a nasty little low . Snow on the western flank ?? 

Looks marginal but certainly a good chance for higher ground. 

[Cheshire Freeze]

On 29/11/2021 at 18:28, Ali1977 said:

Looks good with a slider on its way 

Need heights to rise a little more around Norway, otherwise the lows will phase too far N

[Mike Poole]

1 minute ago, CreweCold said:

Need heights to rise a little more around Norway, otherwise the lows will phase too far N

Yes, the GEM was better in this regard.

[Allseasons-Si]

Huge wedgey at 144 on the ECM,...

 

's...make...'s

 

Edited November 29, 2021 by Allseasons-si
wrong chart

[clark3r]

One things for sure on todays models there is a lot to be decided at relatively short range, interesting times 

[mountain shadow]

T+168!!

What a turn around.