Model Output Discussion Autumn 2024

[LRD]

 Jacob Mate, you could have a wall of high pressure stretching from Greenland to the Azores but all it usually takes is one pathetic, weak, little low off the East or NE coast of Canada to break it all down, eroding it from the southern tip of Greenland and squashing it down to the rough vicinity of the Azores

[AO-]

 Jacob

Would not worry too much about the shortwaves on GFS. They are often, in my opinion, exaggerated. But, on the other hand, they are synopticcsaly possible regarding the GFS12. It is the depth which is questionable. If the vortex will be on the Siberian side with no or limited activity over Canada, it may still work out well. We are talking about 9-10 days, which is just within the forecasting range of the EC operational. 

[Jacob]

 AO- So it looks okay for cold? The PV is over Siberia and it doesn’t look like there’s much going on in Greenland

[AO-]

 Jacob

Not within the reliable obviously. It is difficult to say because the pv is flirting with record high levels. On the other hand there is the amplification plus a negative AO that is going on atm. I'm no expert on background drivers, so I would not bet on it. But what I see in the GFS charts as well as the last frames of EC12 is pretty promising imo. They are possibly the precursor for winter early December or late November. 

If anyone disagrees, please tell...

Edited November 5, 2024 by AO-

[Cambrian]

12z GFS op, end of run…

 

…Ninja November. 

[northwestsnow]

UKMO isn't interested in retrograde  either 

GFS is, still 

UKMO much flatter and aggressive with the Atlantic lows and the anticyclone cant get as far north.

Think I've been around long enough to suggest there isn't going to be HL blocking...

[TSNWK]

 Cambrian  1st bank of the season......

[AO-]

 northwestsnow

And what about EC's 168 of this morning? Was pretty flat as well. Turned out to be a nice ridge at 240h. We have to wait. Maybe even two or three weeks. Or even three months...

[booferking]

 northwestsnow come on i think your around long enough to know its a viration of the same theme and its not until after mid month we're it gets interesting even gem is having a go later after looking similar to ukmo patience my friend its the second pulse of heights were it gets interesting.

[northwestsnow]

 AO- 

EC out shortly ,let's see  

[Met4Cast]

Ah, classic GFS FI chart!

Still, gives us something to look at if nothing else! 

[Ali1977]

I’ve seen worse November charts, no PV of doom over Greenland . It wound feel quite chilly under that !! 

 

looks better at 240 with heights building over Greenland - regardless of where it goes it’s nice to have no wind and rain for now!! 

Edited November 5, 2024 by Ali1977

[northwestsnow]

EC is chilly and dry in the main.

I can live with that !!

[ANYWEATHER]

Well next week ,according to the gfs is not without interest, none of the usual November charts of wet and mild this year!

[blizzard81]

 northwestsnow Yep, I like the ecm run. Seen many archive charts with similar set ups which lead on to wintry conclusions. The key is the fall in pressure over mainland Europe which helps to elongate the high over us which then aids in retrogressing the high out towards our north west. That's the plan anyway.

[AO-]

 blizzard81

Please not a west based NAO- again like the past three winters that didn't deliver.

At least EC12 is on the mild side for here. A little improvement on the long term. Lets await the clusters

Edited November 5, 2024 by AO-

[chris888]

still some greenland blocking on the 12z gfs but it's 384hrs away so obviously needs to be taken with a huge grain of salt

[Ball Lightning]

This is basically as reliable as guessing due to long range, but here we have a major snowfall event for London and the Southeast on the CFS for mid-late January after a continental low retrogresses with cold air being dragged in from a Siberian high. December looked grim with a <945mb storm on Christmas day along with repeated visits from the Azores high.

[Jacob]

 hailcore It’s even less accurate than that lol. It’s like guessing a random number between 0 and 10000

[Mcconnor8]

 Jacob Nah I think that run has it nailed you know, I've started counting down the hours until the Winter Wonderland, only 1,858 to go

[Bogman]

 Mcconnor8 what day is that?

[WYorksWeather]

Very quick EC clusters summary - no time for anything more this evening. Interest is days 8-10 and 11-15 so I'll focus on those.

At days 8-10, clusters 3 and 4 are favourable for at least more of a north-westerly, but outweighed roughly 65/35 in the ensemble by non-descript or milder options.

At days 11-15, two clusters, and almost the opposite split. The ensemble divides roughly 60-40 towards the colder Cluster 1 over the relatively mild Cluster 2 (though Cluster 2 becomes a little cooler, perhaps near average, by day 15).

[blizzard81]

 WYorksWeather I certainly prefer these to those seasonal charts you just posted on the winter thread

[AO-]

Good morning, 

The morning charts show that an MLB is the best possible option. Both EC and GFS are not very keen on a split of the tpv. The hp stays untill the end, so precipitation rates are low, but have increased. Teperatures are around average after a mild interlude, I suppose. The really wintry options are absent:

 

 

Edited November 6, 2024 by AO-

[blizzard81]

 AO- Those are last night's ensembles.