Model Output Discussion - Spring Has Sprung

[feb1991blizzard]

  @bluearmy

Yes, some flatlining eps members today close to -10c, all building up to something very cold late feb, possibly record breaking cold.

[Mike Poole]

A little more cheer for coldies on the clusters this morning, T192-T240:

Clusters 3, 4 and 5 all develop an Atlantic ridge extending into Greenland.  Cluster 2 is the only really flat one, with clusters 1 and 6 hinting at height rises to the NW.

T264+:

+NAO not the favoured outcome here, a collapsing Atlantic ridge on cluster 2, clusters 1 and 3 maintain some ridging to the NW.  I think the earlier timeframe needs nailing before giving too much credence to the scenarios in this one.

I think the message that is most clear, is that the relentless zonal train is going to run out of steam.  What is not clear (to me anyway) is what will replace it.  There is no guarantee it will be a UK cold scenario, but the chances are there - think it will take a while before reality becomes clear.  

[bluearmy]

  @feb1991blizzard that’s quite an extrapolation feb !

[Dennis]

JMA 0z 

[Chesil View]

Just as an over view, the models will do what the models will do in reaction to what they perceive the background drivers are showing and the actual weather will do what the actual weather does in reaction to what that mix of drivers is actually doing.

So if the actual weather/atmophere reacts/decides that winter the biggest chunk of winter this year will be mid Feb to mid March (like 2017/18) then that's what will happen. Regardless of met office book keeping stipulations about which season it is at the time.

[Dennis]

GFS6z

vortex time to dive south 

 

Edited January 25 by Dennis

[offerman]

Just read the next monthly forecast from Netweather. 
Will be really interesting to see if the synoptics play out. 
Will be nice to have some calmer dryer weather for a change for all of us.

if high-pressure does take control will be good to see some nice dark, clear, starry nights. 
Will be interesting to see how long any Greenland high will sustain, and with pressure forecast to drop over scandinavia in some of that period could be quite chilly too. 

[Battleground Snow]

  @Dennis

Overnight gefs suggested (albeit very weakly) that an intense high pressure system would transfer east across Canada towards Greenland, this may be the mechanism to how we get to what the ecm46 is showing.

The gfs 06z seems to be picking this signal up earlier, we do need the Atlantic to also play ball though.

 

[Lukesluckybunch]

Gfs looking quite a bit different at day 8..less traffic too the north,heights fading over europe..hopefully this can turn out good...

[Lukesluckybunch]

It looks to be trending a bit west based on this run...

[MJB]

Interesting set up evolving 

 

[Dennis]

0z and 6z 

thats why i say that an 500hpa chart has  problems to the other paramaters we have ....

so im seeing much more on forecasts , one of them is a -NAO 

[bluearmy]

Gfs following ec op 

the control went amplified MAR in fi 

[bluearmy]

Something that has stood out to me recently is that the strat profile is very much in tandem with the trop profile out to day 10 (ish)

Gfs then completely changed the lower strat and trop beyond that. If the two remain in tandem then we should expect a scandi/ hopefully sceuro trough and the area to our west is up for grabs 

That leaves a wide number of solutions beyond the 4th 

Edited January 25 by bluearmy

[Dennis]

  @Lukesluckybunch

yes W based first .....

Edited January 25 by Dennis

[MJB]

A wintry feel for sure if verified

[IDO]

The GFS 06z shows the best-case scenario of a mini-ridge giving a brief cool down but west-based, so the milder end of the cold spectrum:

But the overall pattern remains the tPV alpha circulating to our north back and forth between Greenland and Scandi, so any HLB'ing is almost negligible.

[Lukesluckybunch]

The low off the eastern seaboard at day 10 phases with the troughing to the north and northeast..hopefully less of a feature in the next runs..we need the separation as the phasing really ramps up the Azores hp

Edited January 25 by Lukesluckybunch
Adding

[Dennis]

i think a big patterchange is setting up ....

MJO is heading to 7 with retro signs later Febr

[IDO]

  @Lukesluckybunch

The jet is driving the westerly flow, not the circulating tPV (tPV is just preventing any HLB'ing):

So we will see swarming off that jet, LP systems, preventing any ridges from sustaining from the blocking over the US/Pacific. The jet is strong, and it is hard to see anything cold develop from that.

It does appear the Asia/Pacific side has got the mid-latitude block that we had over the UK earlier this month that led to cold:

[CoventryWeather]

Wouldn't take much notice of the GFS in the next few runs - seems all over the place past day 5. 

Easily shown as it blows up a low intensely around day 12, showing it has no clue. 

MAR around 4/5th February looking at the EPS? Earlier than expected I would say. 

[Dennis]

part 2 GFS

[Don]

5 hours ago, LetItSnow! said:

Projected maximum temperatures widely in the mid teens with a couple 16Cs dotted around. You can usually add to that. Looks like we could potentially start February 2024 similarly to how we did exactly twenty years ago.

This is exactly what I alluded to last week.  However, something to take heart from this is that the second half of February/early March 2004 was cold and snowy for some.

[bluearmy]

39 minutes ago, CoventryWeather said:

 

MAR around 4/5th February looking at the EPS? Earlier than expected I would say. 

Not sure it is early as a feature

looks transient on the ens suites and I’d be surprised if we didn’t get a toppler of some sort around that time 

 

[Mike Poole]

1 hour ago, bluearmy said:

Something that has stood out to me recently is that the strat profile is very much in tandem with the trop profile out to day 10 (ish)

The Strat profile has been very much in tandem with the trop profile all winter!

With a strong vortex that would be a bad thing.  But despite a very weak vortex, it has even so managed to thwart us at every turn.  Maybe our luck about to change?

Edited January 25 by Mike Poole