Model Output Discussion - Happy New Year!

[igloo]

who no's we could well get a SSW event. the GFS is hinting at something colder and now the CFS is showing even colder stuff we can only dream

 

[BLAST FROM THE PAST]

It’s still thereon the 00z

BFTP

[Jordan S]

Pretty good agreement on a disturbance moving through tonight bringing some sleet and snow perhaps to parts of northern Ireland later this evening then to southern Scotland perhaps northern England overnight but there is uncertainty in the placement atm. 

Gem..

GFS..

Hirlam..

Icon..

Elsewhere wintry showers some perhaps quite heavy. Also more organised showery rain from the disturbance likely pushing across the south and southeast during this evening and the early part of the night windy with this. 

Edited January 27, 2020 by jordan smith

[That ECM]

Gfs and ecm going for this build of heights out in the Atlantic. The form horse from there is for the high to move east and over us. There is tho a chance it could go north or north east which would make fi look very interesting. Day 11 & 12 would have looked great on ecm. 

Edited January 27, 2020 by That ECM

[Anthony Burden]

High pressure looked to build to the north west in 8 or 9 days a much better chance this time of some cold

to very cold weather.Looking this time for pressure to be to the north of us rather than collapsing over U.K. 

Possible polar vortex split could be a big reason for the high to remain to our north or northeast.

[DavidS]

4 hours ago, igloo said:

who no's we could well get a SSW event. the GFS is hinting at something colder and now the CFS is showing even colder stuff we can only dream

 

That would be quite something!

[DavidS]

For once the 00z doesn’t drop the ball

 

[LRD]

Well, well, well. ECM's last three frames have a lot of promise. High to our north and north-west

Might come to something, might not. But at least something of interest is being shown on the models now, which is more than we've had the past miserable 8 weeks

Edited January 27, 2020 by LRD

[IDO]

Looking at the mean for D10:

There is a sign of HP building but the op needs to drag the ensembles that way as they are not close yet. Looking at the 2m temps for my location, not quite an outlier, but the op the best case scenario or close to it. We have seen heights over-amped by GFS many times at this range so need a few more days for any expectations of anything as cold as the op. It is another play on HP close to the UK, mainly dry but a cold-high on this run.

The D9 charts:

ECM supports that one-day build towards higher-lat, but both ECM and GFS op high hit the tPV to the north and the high cannot build or sustain north. The GEM less keen on that Atlantic high getting as far north.

The GEFS remain incoherent as a whole and best to wait till we see the net result of the potential at D9. So those that want a cold high have a chance of several days if the GFS op is correct. Otherwise more standard fare. The MJO signal on the GFS looking to take us into phases 2 and 3 (higher amplitude on the latter). The strat split may be more of a driver late winter and assuming it verifies (likely ATM) we will have to see where the pieces fall for the UK, but it will surely be an upgrade on the winter so far?

[chris55]

Both ECM and GFS picking up this height rise in the northern Atlantic around day 8 - UKMO also suggesting that progression looking at the 144. 
 

A few runs with this idea now so something to watch as the set up comes into closer range.

 

The high looks quite far north so hopefully we can get something cold setting up!

[feb1991blizzard]

Cold CFS.

[bluearmy]

another amplification beyond day 8 but how does it pay out and is there another one to follow ??  The polar profile is the big variable and ten days away is lala land 

[West is Best]

Guess we will latch onto anything after what has happened so far this winter but I have to say that in any normal scenario what the GFS and ECM are tantalising at c. T216 (ECM) and T228 (GFS) would hardly get a second look. It may develop into something more substantial which often happens. At the moment we'll all seize it with alacrity but it's not exactly thrilling.

[MikeC53]

Well the best charts of the winter so far at around day 9, although that is of course not saying much and we know that Azores Lows often don't materialise and HP often ends up further South.

[Dennis]

well more times now 5/6 febr is to watch....

[carinthian]

Best winter overview chart of the season so far from ECM at 168t. Sort of backed up by this mornings extended UKMO chart. Our team over here talk about some interesting weather to affect South Britain (  Wales to the Wash ) in the time span 168t-216 T in the form of a wave or disturbance from the SW to bring quite a bit of rainfall and possibly snowfall to higher parts later. Of course more runs needed as the jet may even push this into France but the chance of colder weather are now getting in a bit closer in the time span. Think also to be noted that the prospects of the PV heading into Northern Finland may help the course to plotting a colder outlook. Hope the change comes soon for you guys as the winter has been rotten so far for cold lover anyway. I am really more optimistic this morning by the models and discussion just had.

C

[Methuselah]

A slightly better (I wonder where that sits within the ensembles!) positioned HP cell, on today's 00Z run, at T+231:

    

Though, by the very end, our resident  European HP is back in place:

    

But there're still no signals for a long-lived cold and snow spell, in the ensembles:

    

Give it time, eh?

[BlueHedgehog074]

Models in general going for a changeable Westerly flow within the next few or so days. Today (particularly for Northern UK areas), and tomorrow and for part of Wednesday will be quite chilly as the South-Westerly to Westerly/North-Westerly flow brings in air from a cold origin.

Accompanied by fairly low heights over the UK too. Though some of the low heights will lift out on Wednesday. The showers and longer spells of precipitation this chilly Westerly flow will bring could be of a wintry nature. Tomorrow continuing to look the best day for wintry weather and some of these showers, especially the heavier ones, could see some sleet, perhaps snow, reach lower levels at times (examples included between today and Wednesday).

 

The weather then looks to become a bit more warmer, as the flow changes to more of a milder flow from the South-West. Low Pressure out West orientated more in a South-West to North-East direction to the North-West of the UK while High Pressure ridges over to the South-East of the UK. The area that’s likely to see the best of any settled breaks between the rain and showers. Some cooler returning Polar Maritime and Polar Maritime air could continue to affect more Northern parts of the UK at times.

Peaking ahead at 216 hours, 3 of the longer range operational models below are showing High Pressure being held captive to the West of the UK in the Atlantic. And colder air spilling down from the North.

00Z GFS

 

00Z ECMWF

00Z GEM

The GEM not really showing much of a proper ridge in the Atlantic. High Pressure is to the South-West of the UK, but a lot flatter. Still though managed still bring in a cool flow from the North-West. And it does look a bit more blocked upstream towards 240 hours:

It may be possible that while the GFS and ECMWF are probably playing the over-amplified game of the Atlantic ridging, it’s also possible the GEM may be underestimating amplification of High Pressure at that 216 hour time frame. I think since the GFS continues to play about with quite a pronounced mid Atlantic ridge and that the ECMWF has picked up on this, am tempted to pick their side.

Best, however, to be cautious as have certainly been in this position a number of times before. Could do with the ridging that the models show shifting out of that Eastern Canada/Eastern Northern America area to not get flattened too quickly. Have it sufficiently build far enough North in the Atlantic before the mischievous Lows to the West of the High squash it flat! 

Gonna keep my hopes low for now as is this outlook is still locked away in the cupboards of FI. But the Atlantic ridge and Northerly scenario does seem to be getting some improving support. Again, some likely wintriness in these next 2 days, in particular, for Northern high ground, to keep some going for now. 

[Dennis]

maybe a winter day  lets watch the progress of the AO ; any have Teleconnections?

 

 

[Methuselah]

Well, I obviously have little or no idea what weather-pattern will dominate, come mid-late February...But, IMO, it's well worth remembering that, when last year's all-time highs were set, T850s were around +9C...?

    

[IDO]

Not a given but as expected the height rises of the 0z less so on the 06z:

0z>06z>

As probabilities go that was a good bet. More of a brief NW'ly flow than the 0z N'ly, and more fleeting cold, though still a cold high as it slowly trundles through our region. The ECM mean is closer to the GFS 06z than it was the ECM 0z op, so again expected:

ECM Mean & op at D9> 

So another possible settled period coming post-D8 for maybe 4-6 days. 

Edited January 27, 2020 by IDO

[SLEETY]

Can’t get the High to move far enough North,but this is the gfs 06 run,always seems to want to flatten the pattern quickly,whenever it tries to amplify it.So I would not take too much notice of what it is showing.

[IDO]

...more interest for me is post D10 and how the tPv is now being modelled:

So there is mega cold moving south to mid-lats, just the UK in the wrong place as currently modelled. Whether we can tap into this cold or remain with scraps is the big question if this pattern change does verify?

[IDO]

...retrogression of the UK high in FI is a good signal:

Usual caveats but this run suggests that background signal are impacting on the trop. Hopefully not a false dawn, though we know there can be flips quickly so such a development a possibility...

[ICE COLD]

If you don’t succeed first time then try again . Gfs 6z is having another go