Model output discussion - proper cold spell inbound?

[January Snowstorm]

The synoptics were never great and a couple of us commented on this. We've no Greenland high and heights to our northeast are transient for now. What's causing the real interest is that the uppers to our Northwest look exceptionally good throughout. So while it's not a constant freeze up it could deliver quite a bit if weather Inc snow.

Mild sectors = heavier ppn which is one positive. Also all the indicators are for plenty fun and games throughout February with a strat event looking very likely. So in general loads to be happy about with a sniff of something very special still possible

[ICE COLD]

7 minutes ago, blizzard81 said:

I must admit, the ukmo seems to have a good track record at the 96 to 120z timeframe. Even more so in these situations. Infact it could be argued that it has out performed the ecm in similar circumstances at the 4 to 5 day range. 

Yep I think a lot of people on here forget what achally happened the other day the UKMO stood firm on height rises to the north east and ECM /GFS did not want to know . So for people to be not really putting any faith in UKMO would be silly . We will no by tomorrow morning ?

[MattStoke]

Hmm. Those fax charts do look a bit tasty, and they should be more reliable than raw model output.

Occluded front from the east pushing quite far west across England late Sunday/early Monday. That should pep up the shower risk quite far in land across England.

Trough near to the South East. That would increase the shower risk across south eastern areas on Monday.

Tuesday's frontal system getting in towards the central part of the UK, probably giving snow quite widely should it have enough oomph left.

Then of course you have the potential for streamers and and other small features to pop up at short notice. 

All minuscule features (the Atlantic front aside) and all likely to chop and change a bit but promising none-the-less.

[john mac]

4 minutes ago, feb1991blizzard said:

They can deliver but usually to deliver big dumpings they need lower 500mb and a strong flow advancing the cold westwards, this is a glancing blow -hope you do get some - like I say you should see something but cant see you getting a right dumping. at the end of next week different story, more potential plus given the timeframe more room for upgrades too.

Yeah agreed there. However as SM said yesterday. There will be snow showers off the North Sea and they will be lighter in nature but also very slow moving. So some de ent accumulations can’t be ruled out.

[Snowman.]

18 minutes ago, blizzard81 said:

The age old question arises again though. The op is higher resolution so has more chance of being correct, especially at 120hrs. 

Another one is that they're all useless due the set-up and it's better to play the waiting game.

But that's boring and doesn't create drama.

[Mike Poole]

3 minutes ago, Optimus Prime said:

Daft question this but what's the confirmation like, that far out? Strat charts tend to be better good indicators even at that range? 

It looks like it's going to happen now, starting to show on ECM as well (Berlin site) and from the Met Office update, they seem to expect it too, but is it guaranteed for cold in UK is my question.

[Frosty.]

Just flicked through the Ecm 12z ensemble mean and I have to say I thought I was looking at the 00z again..no downgrade that I can see!!..

[Daniel*]

4 minutes ago, Optimus Prime said:

I don't think so, Thames streamer normally requires a direct easterly with positive wind shear. There isn't much of a gradient on that chart.

No! They require an ENE wind just like that. Where’s that SSTs map you posted, 

[tight isobar]

29 minutes ago, Daniel* said:

That shows a streamer  

Thames streamer I think.........

Given atmospheric basis..a streamer scenario is ripe!!

It looks to grudge some for there -location isnt of note, due to the formats/synoptics..

But thats the way it rolls.

And as regards(any notable snowfall) within next 3/4days, its not difficult to note south -south eastern quadrant..are in a favourable position...

And modeling flags this!!!

Edit lets see what 18z build on...as a whole on the cold spell..as well as the upper mentioned!?

Edited February 2, 2018 by tight isobar

[Paul Sherman]

Having wrote an almost paper on the Thames Streamer event of 2009 which is on this forum somewhere I can with 100% certainty say the Fables Thames Streamer needs an ENE wind direction, but only so slightly North of East. Steve Murr has the exact compass position I believe.

Other streamers affect the SE as well, The ESE Streamer affects more of Herts and NW London.

The NNE Streamer hammers Kent and East Sussex.

[tight isobar]

6 minutes ago, MattStoke said:

Hmm. Those fax charts do look a bit tasty, and they should be more reliable than raw model output.

Occluded front from the east pushing quite far west across England late Sunday/early Monday. That should pep up the shower risk quite far in land across England.

Trough near to the South East. That would increase the shower risk across south eastern areas on Monday.

Tuesday's frontal system getting in towards the central part of the UK, probably giving snow quite widely should it have enough oomph left.

Then of course you have the potential for streamers and and other small features to pop up at short notice. 

All minuscule features (the Atlantic front aside) and all likely to chop and change a bit but promising none-the-less.

Ive been banging this drum for 2 days..but get shot down.

Anyway lets see how we evolve..b4 upseting any other members!!!

[Optimus Prime]

7 minutes ago, Daniel* said:

No! They require an ENE wind just like that. Where’s that SSTs map you posted, 

Oi! Stop telling porkies you. February 2009 is the best example I can find (extreme, granted);

We're bloody light years away from that fella.

[tight isobar]

16 minutes ago, Paul Sherman said:

Having wrote an almost paper on the Thames Streamer event of 2009 which is on this forum somewhere I can with 100% certainty say the Fables Thames Streamer needs an ENE wind direction, but only so slightly North of East. Steve Murr has the exact compass position I believe.

Other streamers affect the SE as well, The ESE Streamer affects more of Herts and NW London.

The NNE Streamer hammers Kent and East Sussex.

Then we keep note of any vent gradient nxt 24/48 hrs..

Looks 50/50 to me!!

Edited February 2, 2018 by tight isobar

[Frosty.]

2 minutes ago, Richard Fisher said:

Not according to Ian Ferguson on his BBC 6:50pm broadcast cold snap peaks Wednesday.

From what I've seen on the models so far today we are looking at reloading cold shots from the NW beyond the very cold continental incursion..lots of polar maritime type airflow.

[A.J]

3 minutes ago, tight isobar said:

Given atmospheric basis..a streamer scenario is ripe!!

It looks to grudge some for there -location isnt of note, due to the formats/synoptics..

But thats the way it rolls.

And as regards(any notable snowfall) within next 3/4days, its not difficult to note south -south eastern quadrant..are i a favourable position...

And modeling flags this!!!

There aint no grudge party like a south of M4 grudge party ...lol......I'm probably talking complete ballcocks, but I think we're just seeing natural variations in the outputs today, it's going to get a lot colder for sure, as for the pinning down of snowfall at this range for any one location?....a pointless and fruitless exercise I'd wager (apart from south of the M4 of course, we know it will rain )

[supernova]

25 minutes ago, Mike Poole said:

Strat warming getting closer on GFS -  seems like a double warming and a split of the stratospheric PV.  

A nagging doubt though - a split like this will have significant implications for mid-latitude weather down the line, a 'reshuffling of the deck' so to speak, but if we've already got the cold in place, do we want the deck shuffled?

 

Only if we're shuffling towards something colder...

[bobbydog]

1 hour ago, Optimus Prime said:

 

 

Would you like me to mail it to you as well?

I love being right.

strange, because the NOAA website (who i would trust more) says below to average round our shores...

possibly not as "right" as you presume...

[Methuselah]

4 minutes ago, Frosty. said:

From what I've seen on the models so far today we are looking at reloading cold shots from the NW beyond the very cold continental incursion..lots of polar maritime type airflow.

That's pretty much what I say, too, Karl. And, at 10-days' hence, how much detail can one expect anyway? I'll wager (nothing!) that at least one more slider will happen before March is out...?

[Richard Fisher]

8 minutes ago, feb1991blizzard said:

So nothing after that then?? - is that Just for West country though.

He appeared to be talking about the cold snap rather than local but I could be wrong. He did not  show any concern with snow amounts or the severity of the cold snap. 

[tight isobar]

5 minutes ago, ajpoolshark said:

There aint no grudge party like a south of M4 grudge party ...lol......I'm probably talking complete ballcocks, but I think we're just seeing natural variations in the outputs today, it's going to get a lot colder for sure, as for the pinning down of snowfall at this range for any one location?....a pointless and fruitless exercise I'd wager (apart from south of the M4 of course, we know it will rain )

?-fairplay.

However on a serious note any easterly flow...even with a north east fraction..will be a favourable postion....for eastern/south-eastern england.

Lets talk dynamics when the 18z roll.

?

[Johnp]

10 minutes ago, feb1991blizzard said:

So nothing after that then?? - is that Just for West country though.

Don’t forget ‘peak’ doesn’t mean ‘end’.

[Optimus Prime]

6 minutes ago, bobbydog said:

strange, because the NOAA website (who i would trust more) says below to average round our shores...

possibly not as "right" as you presume...

Their data is pulled straight of the same website as yours; the NOAA except, is has heightened resolution (30km as opposed to your 50km) 

Ultimately they both basically show a very similar picture. Except mine is more precise

"Sea surface temperature (SST) and SST anomaly maps are generated from NOAA Optimum Interpolation SST version 2 (OISST V2). OISST is a 0.25°x0.25° blendend dataset derived from satellite, ship, and buoy measurements. The SST anomaly is based on a 1971-2000 NOAA climatology"

Forgot to add; It's blended with 3 different forms of measurement. It's basically a composite.

Edited February 2, 2018 by Optimus Prime

[Man With Beard]

54 minutes ago, Daniel* said:

Oh what do we have here? T+36 I myself will be watching fax charts closely in the coming days. It’s the best way of having a good idea of precip, and Euro4 is now getting within range. 

I'm fascinated by the 474 dam line over Canada. Not seen that before!

[feb1991blizzard]

5 minutes ago, Richard Fisher said:

He appeared to be talking about the cold snap rather than local but I could be wrong. He did not  show any concern with snow amounts or the severity of the cold snap. 

I would have to say I would agree with him up until next Thursday looking at the models, howerver I would phrase it differently, I am concerned when we don't get disruptive snowfall rather than when we do!

[bobbydog]

Just now, Optimus Prime said:

Their data is pulled straight of the same website as yours; the NOAA except, is has heightened resolution (30km as opposed to your 50km) 

Ultimately they both basically show a very similar picture. Except mine is more precise

even if yours has a slightly higher resolution, how do they come up with a marked difference in SST's using exactly the same data? how do they make 'colder' into 'warmer' by looking a little closer?