Model Output Discussion - Into Winter

[Cheshire Freeze]

GEM is decent too

1 minute ago, Mike Poole said:

GEM out to T210, very good:

Yes Mike.

I think a few of us have been quite bullish about Christmas cold, in the face of a dodgy couple of days of output.

[That ECM]

If Christmas Day is important for people to see snow, gfs has upgraded that.

[geordiekev]

17 minutes ago, Spah1 said:

YYYYYYYYEEEEEESSSSSS !

UKMO 144

 

Very Similar to icon for our locale, though UKMO brings cold earlier

Edited December 16, 2023 by geordiekev

[cheshire snow]

Very nice.

[Cheshire Freeze]

GEM max temps Christmas Day-

Cold.

[Cheshire Freeze]

Just now, cheshire snow said:

Very nice.

Yes and notice the North Atlantic ridging appearing…which is completely in line with expectation.

Remember a few days ago when I said expect up stream amplification to increase as the NWP gets to grips with the situation? Well that’s what we’re beginning to see. Both the GEM and GFS have it this morning.

[Battleground Snow]

Just now, Cheshire Freeze said:

Yes and notice the North Atlantic ridging appearing…which is completely in line with expectation.

Remember a few days ago when I said expect up stream amplification to increase as the NWP gets to grips with the situation? Well that’s what we’re beginning to see. Both the GEM and GFS have it this morning.

Euro heights be gone!

Ukmo doesn't box off the low at 144, but is still a cold run anyway, be interesting to see what Ecm does later, but to get upgrades on 00z runs is a great sign

[That ECM]

Christmas Eve. Too soon to post this?

[Kasim Awan]

6 minutes ago, Cheshire Freeze said:

GEM max temps Christmas Day-

Cold.

That's definitely on the cold side for a Bartlett.

[Cheshire Freeze]

Just now, Kasim Awan said:

That's definitely on the cold side for a Bartlett.

It’s now a Nartlett

North Atlantic Ridge-tlett

[Kasim Awan]

1 minute ago, Cheshire Freeze said:

It’s now a Nartlett

North Atlantic Ridge-tlett

A Cartlett Nartlett - a cold Nartlett.

[northwestsnow]

UKMO is very brief..

By 168 the pattern is collapsing

 

[Daniel*]

UKMO gone full pelt… strong pressure drop south into central Europe, unusually strong NW winds with Arctic air being fed in, the next few days would likely offer wintriness quite widely. A white Xmas could well land this year…..

[northwestsnow]

Just now, Daniel* said:

UKMO gone full pelt… strong pressure drop south into central Europe, unusually strong NW winds with Arctic air being fed in, the next few days would likely offer wintriness quite widely. A white Xmas could well land this year…..

No the cold is being shunted away 24 hours later..

GFS/ GEM brilliant though ..

[That ECM]

2 minutes ago, northwestsnow said:

UKMO is very brief..

By 168 the pattern is collapsing

 

For you nerves, I would stick with that for a bit.

[Mike Poole]

I do wonder if the lows in the region indicated could sort themselves out with regards alignment, whether a future run might show WAA up the west side of Greenland around T204:

[Cheshire Freeze]

Some decent thicknesses associated with that GFS northerly, temps struggling to around freezing on Christmas Day

Just now, Mike Poole said:

I do wonder if the lows in the region indicated could sort themselves out with regards alignment, whether a future run might show WAA up the west side of Greenland around T204:

Entirely possible Mike. Though not looking probable at present for a full GH.

I agree though, it’s a bit of an open goal.

I’d say more towards the first week of Jan for proper GH chances.

[That ECM]

5 minutes ago, Mike Poole said:

I do wonder if the lows in the region indicated could sort themselves out with regards alignment, whether a future run might show WAA up the west side of Greenland around T204:

As good as gfs is there is soooooo much to be sorted. Ukmo illustrates that at T120/T144. 48 hours and they should all be on the same page? Sure would like ecm to follow gfs. Won’t hold breath tho.

Edited December 16, 2023 by That ECM

[Kasim Awan]

9 minutes ago, northwestsnow said:

UKMO is very brief..

By 168 the pattern is collapsing

 

I have to disagree. Between 144h and 168h there is barely any movement, we've seen much faster evolving northerly patterns before.

It is looking more likely that this will be a temporally stretched wavelength. This largely due to stronger phasing of the main low in the 3 to 4 day time frame and the resultant lack of left over low pressure over southern Greenland (where we would look for a breakdown of this wave) in the 5 to 8 day time frame. The result is a very large and as a result drawn out pattern, with rather little energy being shunted out of Eastern Canada. This is good news for the UK - because it gives time for the low to become entrenched over central Europe around 6-10 day time frame aswell as allow moderate builds of mid atmospheric pressure around southern Greenland. The JMA is still going for this aswell - such significant phasing / low amplification can result in alterations upstream into the Arctic. I know it's the JMA but it has been solid and rather accurate in it's phasing. GEM/GFS are similar. 

Edited December 16, 2023 by Kasim Awan

[Daniel*]

The UKMO day 5 is really quite concerning thankfully I have not seen much support for a similar solution. This would be an impactful weather event a lobe of polar vortex experiencing explosive deepening to SE of Iceland and then pushing southeast down North Sea. I can’t say I’ve ever seen a strong storm take that NW>SE trajectory. I suppose it is possible otherwise it wouldn’t be shown!

[northwestsnow]

Just now, Kasim Awan said:

I have to disagree. Between 144h and 168h there is barely any movement, we've seen much faster evolving northerly patterns before.

It is looking more likely that this will be a temporally stretched wavelength. This largely due to stronger phasing of the main low in the 3 to 4 day time frame and the resultant lack of left over low pressure contribution in the 5 to 8 day time frame. The result is a very large and as a result drawn out pattern. This is good news for the UK - because it gives time for the low to become entrenched over central Europe around 6-10 day time frame. The JMA is still going for this aswell - such significant phasing / low amplification can result in alterations upstream into the Arctic. GEM/GFS are similar. 

UKMO 144

 

168

Looks like a collapsing mid Atlantic high to me mate 

[Kasim Awan]

Just now, northwestsnow said:

UKMO 144

 

168

Looks like a collapsing mid Atlantic high to me mate 

For 24 hours that's very little change. Very slow moving. We've seen snow in our ends from patterns that see that much easterly shift within 3 hours.

[That ECM]

[Cheshire Freeze]

1 minute ago, Kasim Awan said:

For 24 hours that's very little change. Very slow moving. We've seen snow in our ends from patterns that see that much easterly shift within 3 hours.

Looks fairly good in terms of strat too with that slow moving wave impacting against the HP out east.

[northwestsnow]

3 minutes ago, Kasim Awan said:

For 24 hours that's very little change. Very slow moving. We've seen snow in our ends from patterns that see that much easterly shift within 3 hours.

The million dollar question is ukmo = rain or snow.

Isobar very tight uppers look around -4 to -6..

144

168

 

2 minutes ago, That ECM said:

GFS much better.

Edited December 16, 2023 by northwestsnow