Model output discussion - The Hunt For Cold

[Tim Bland]

CFS looks bang on to me

 

[Cheshire Freeze]

2 minutes ago, Tim Bland said:

CFS looks bang on to me

 

Oooof!

*drools profusely*

[Allseasons-Si]

39 minutes ago, Tim Bland said:

CFS looks bang on to me

 

It's not going to be no where near bang on at 1254 hrs away, they can't even get it bang on less than 96 but nice to look at,cheers

[Allseasons-Si]

The latest gfs has the tropical storm/depression running up the eastern seaboard of N America on this run,this could prove some model headache's in the medium term,hopefully for the better and send some ridging up into Greenland.

[feb1991blizzard]

The theme of southerly tracking and disrupting lows continues and drives waves into the pole, it is significant that the usual default pattern on the GFS has changed from zonal to this, something is afoot, LIA footprint is evident.

[Ross Andrew Hemphill]

2 minutes ago, feb1991blizzard said:

The theme of southerly tracking and disrupting lows continues and drives waves into the pole, it is significant that the usual default pattern on the GFS has changed from zonal to this, something is afoot, LIA footprint is evident.

What’s all this LIA malarkey? Is the BFTE coming for a more permanent stay? 

[Allseasons-Si]

2 minutes ago, feb1991blizzard said:

The theme of southerly tracking and disrupting lows continues and drives waves into the pole, it is significant that the usual default pattern on the GFS has changed from zonal to this, something is afoot, LIA footprint is evident.

Ouch!!!

but that ridge is huge to our NE.

[feb1991blizzard]

1 minute ago, Ross Andrew Hemphill said:

What’s all this LIA malarkey? Is the BFTE coming for a more permanent stay? 

Its very unusual to see that pattern repeating at this time of the year, even if its just model output, it shows that there is a signal to do this, it is showing a meridional jet all the time, even if it doesnt come off. something is driving these model runs.

[feb1991blizzard]

2 minutes ago, Allseasons-si said:

 

 

but that ridge is huge to our NE.

Yes, that is as big an autumn pre-SSW signature as you can get.

[Kirkcaldy Weather]

Pretty decent GFS 18z anomaly charts the theme for northern blocking continues ..... 

[Allseasons-Si]

Just now, feb1991blizzard said:

Yes, that is as big an autumn pre-SSW signature as you can get.

Yes,as long as it still shows an amplified pattern,all is good

[BlueHedgehog074]

It’s deep into the dreamland, but one interesting aspect looking at the 18Z GEFS postage stamps - the lack of a flat zonal Westerly flow over the U.K. 

There might be the odd one or two, but most seem to show quite a meridonal pattern. The idea of continuing to see some slow moving and wavy/blocked setups is a real possibility. 

[carinthian]

22 hours ago, carinthian said:

Ok its 2 days on from the last report. Had a chat this morning with our guys and yes, its a nightmare scenario for Alpine forecasting this weekend and into early part next week. The UKMO fax chart at 84t shows the problem being the Arctic front returning as a warm front. Generally, re-curving fronts bring warmer air mass to the lower layers , whilst higher up the air mass remains unchanged for a longer period ( from its original source Pm/Am in this case ) Also, added complication is the exact limit of the cold front . Snow forecasting with height is going to be very borderline. A two model scenario was used with a frontal boundary difference of 100miles , approx. based on the fax chart below and have produced extreme results . One model showing 100cm of snowfall and the other almost zero. So there lies the problem for our mountain forecasters. Again, short range fine mesh model will not become effective until 48 hours before arrival of the front from the NW. Beyond weekend , looks a forecasting dilemma over the Alpine region as extreme air mass battle ground evolves. The view from over here is for a build of a cold the Scandinavian High ( see 528 dam area forecast chart below ). Where we go from here? Basically the answers is Don't know as is the short term snow forecast for the Alpine Region. All very exciting from a forecasting point of view.

Morning all. Crazy weather in the Alps yesterday. Northern alps had plenty of moisture and snowfall cover at 2300m. However, not far from here as the crow flies , 30c was recorded yesterday in the Northern Italian Alps with extreme Fohn creating blow torch conditions with single digit dew points. The weekend forecast is not precise regarding snowfall but SW Alps more favoured at the moment. Plenty to watch as the NW Med Cyclone develops along the strong baroclinic zone over the weekend bringing some really high rainfall totals with some projections as high as 500mm. Where rain turns to snow at height is still going to be the main forecast problem . Tomorrow morning our excellent short range fine mesh model should start to provide some results for us here in resort. However, the inputs looks very messy in this frontal zone . GFS snow picture for the start of next week show favoured locations for some accumulations and possibly first snow cover of the season in Stockholm.

C

[Jonathan Rhodri Roberts]

12 hours ago, Jonathan Rhodri Roberts said:

Still keeping a close eye on that potential stalled rainband that showed over Ireland the other day on the GFS latest run has now moved it east, so heaviest rain Tue & Wed with 90mm close to the coast of south Pembrokeshire but rainfall totals would be much more over higher ground if it stalls across Wales like storm Callum done about a fortnight ago. This could be bad news for the half term holidays next week with a risk of some flooding again but of course it's still 6 days away, so there's plenty of time for things to change.  

A big change on the GFS, gone is that stalled band of heavy rain in the Irish Sea. We do see some large totals showing in NW Ireland and W Scotland but even these don't occur until next Fri/Sat so a long, long, long way off 

[carinthian]

43 minutes ago, carinthian said:

Morning all. Crazy weather in the Alps yesterday. Northern alps had plenty of moisture and snowfall cover at 2300m. However, not far from here as the crow flies , 30c was recorded yesterday in the Northern Italian Alps with extreme Fohn creating blow torch conditions with single digit dew points. The weekend forecast is not precise regarding snowfall but SW Alps more favoured at the moment. Plenty to watch as the NW Med Cyclone develops along the strong baroclinic zone over the weekend bringing some really high rainfall totals with some projections as high as 500mm. Where rain turns to snow at height is still going to be the main forecast problem . Tomorrow morning our excellent short range fine mesh model should start to provide some results for us here in resort. However, the inputs looks very messy in this frontal zone . GFS snow picture for the start of next week show favoured locations for some accumulations and possibly first snow cover of the season in Stockholm.

C

Picture last night taken in the Venetian Alps. Forest fire fanned by the hot fohn conditions that developed the SE Alps yesterday. Not that far from here as the crow flies( see above post ) but plenty of rainfall soon to come !

C

[northwestsnow]

All looks a bit uninspiring after the northerly... LP never far from our shores and a mild Bonfire weekend beginning to look favourite..

[feb1991blizzard]

6 minutes ago, northwestsnow said:

All looks a bit uninspiring after the northerly... LP never far from our shores and a mild Bonfire weekend beginning to look favourite..

If we can get a re-emergence of the scandi high though, the building blocks are in place, it might not directly benefit us now but further on - maybe.

[BLAST FROM THE PAST]

6 minutes ago, northwestsnow said:

All looks a bit uninspiring after the northerly... LP never far from our shores and a mild Bonfire weekend beginning to look favourite..

Don’t be chasing too much too soon.  Plenty to enjoy and I like the ECM a lot.  I think we have to expect a lot of swings during Nov with a chance of everything and anything getting thrown at us and for me a true autumn month.  As long as we don’t get a lengthy run of Sw’lies from Bermuda it’ll be ok, that’s one rut we don’t need

 

BFTP

[summer blizzard]

Euro and GFS diverge this morning in about a week with regards to how they handle a secondary low in the Atlantic (GFS bombs it, Euro keeps it weak at that point). 

The impact is interesting at day 10 because the Euro is headed for another northerly with the low crossing the UK unusually far south (probably through the borders).

[northwestsnow]

15 minutes ago, summer blizzard said:

Euro and GFS diverge this morning in about a week with regards to how they handle a secondary low in the Atlantic (GFS bombs it, Euro keeps it weak at that point). 

The impact is interesting at day 10 because the Euro is headed for another northerly with the low crossing the UK unusually far south (probably through the borders).

That's yesterday's chart

[weirpig]

24 minutes ago, northwestsnow said:

That's yesterday's chart

Is it?.  I know im still half a sleep  and not that it matters at that range but does it not  say Thursday 0z  

Edited October 25, 2018 by weirpig

[northwestsnow]

17 minutes ago, weirpig said:

Is it?.  I know im still half a sleep  and not that it matters at that range but does it not  say Thursday 0z  

Maybe it's this phone I'm on .

[jonboy]

1 hour ago, BLAST FROM THE PAST said:

Don’t be chasing too much too soon.  Plenty to enjoy and I like the ECM a lot.  I think we have to expect a lot of swings during Nov with a chance of everything and anything getting thrown at us and for me a true autumn month.  As long as we don’t get a lengthy run of Sw’lies from Bermuda it’ll be ok, that’s one rut we don’t need

 

BFTP

Autumn is all about change from summer to winter. You would therefore expect to have warm pleasant periods interspersed with cooler colder periods. I believe as we head deeper into November and December we will see cooler/colder becoming more the norm with cooler replaced by very cold

[feb1991blizzard]

11 minutes ago, northwestsnow said:

Maybe it's this phone I'm on .

I had that the other week, i posted a wetter chart because meteo have been slow wrt runs coming out lately, it kept on showing a different run, it showed it as a thumbnail correctly, but every time i clicked on it, it reverted to something else, in other words you could see it was the correct chart until you actually clicked it/

[Mapantz]

6 minutes ago, feb1991blizzard said:

I had that the other week, i posted a wetter chart because meteo have been slow wrt runs coming out lately, it kept on showing a different run, it showed it as a thumbnail correctly, but every time i clicked on it, it reverted to something else, in other words you could see it was the correct chart until you actually clicked it/

This is why I don't like people directly linking images from sites. The user should save the image to their device and then upload it to the forum. By doing that, it will show the correct image even when looking at a year or two in the future. Weather sites with model images keep the same links but the images will change, Netweather will probably cache the thumbnail for a period of time, but the direct link will show the updated image.