Model output discussion - mid January

[frosty ground]

4 minutes ago, Steve Murr said:

Man @ the met Liam Dutton confusing all the mild rampers on TWO - Met on board...

I think Liam is saying the opposite to what you think he is saying, it was TWO's twitter that made the rather bold prediction.

[weirpig]

Just now, shaky said:

Just to bring a bit of balance to this place just take a look at latest navgem and see how all of it could go wrong just like that for us!!horrible 06z navgem!!!please just do one!!

Yes Indeed  Always be wary until the Navgem comes on board  said nobody ever.

Some very cold GFS ensembles   Hopefully we will  see some met warnings in the next few days  for those further south than Scotland.

[SMU]

4 minutes ago, frosty ground said:

I think Liam is saying the opposite to what you think he is saying, it was TWO's twitter that made the rather bold prediction.

Yeah - That’s why I deleted the post-

FWiW the initial front sat is borderline -but post that all next week the snow risk increases from the east & NW..

worth is worth noting though as I’ve highlighted since forever is the met agree with how Bad overall the 06z & 18z are..

Edited January 31, 2018 by Steve Murr

[WalsallWeather123]

5 minutes ago, mulzy said:

Be gone pest!

Just wait and see

[Seasonality]

4 minutes ago, shaky said:

Just to bring a bit of balance to this place just take a look at latest navgem and see how all of it could go wrong just like that for us!!horrible 06z navgem!!!please just do one!!

Are the Brazilian and Chinese models on board? What about the NASA model?! Heavens to Murgatroyd, we're doomed I tell you.

[Nick F]

13 minutes ago, feb1991blizzard said:

Technical SSW with daughter vortices spread far and wide on 6z, 1mb charts the best ive ever seen, not just an SSW though, one which would ultimately bring the real cold our way.

Yes, been some interesting stratospheric forecasts over recent days, most particularly GFS, although 00z didn't go for the split, it's returned on the 06z operational again, with twin PVs over Canada and Siberia.

EC hasn't shown signs of splitting yet, but both it and the GFS ops have been showing a warming over Scandi which displaces the PV from Greenland over into N America by day 10.

Combine this with the MJO moving through 7 and into 8 over the next few weeks and we may see a better chance of HLB building from the Atlantic to the N and NE over Scandi later this month.

Interesting times ahead ... even if there isn't a split in the PV, if there is, then we could see cold and snow opportunities extending into early March too.

Edited January 31, 2018 by Nick F

[Stormeh]

I hope you guys down south get your easterly with plenty of snow! Snowing again here today in Scotland and probably more to come. By the way, it better be hot and sunny with overnight thunderstorms when I goto Dorset on holiday this summer 

[Johnp]

3 minutes ago, frosty ground said:

I think Liam is saying the opposite to what you think he is saying, it was TWO's twitter that made the rather bold prediction.

That's my post Steve was taking the p out of!

Thanks for clearing up the confusion - I am certainly not a mild ramper ?

[tight isobar]

Those under the age of 18 look away now..

EXPLICIT CONTENT!!!

[SMU]

1 minute ago, Johnp said:

That's my post Steve was taking the p out of!

Thanks for clearing up the confusion - I am certainly not a mild ramper ?

Didn’t say you were per say -but a whole page this morning of mild ramping when you have the best output in front of us for 5-6 years.. Even the pellet from Shropshire   Saying rain from the NW in -10c air - lol

says it all really.

anyway back on topic.

[karlos1983]

Nice grouping of  some proper cold uppers, none of this namby-pamby -5 stuff 

[feb1991blizzard]

4 minutes ago, Nick F said:

Yes, been some interesting stratospheric forecasts over recent days, most particularly GFS, although 00z didn't go for the split, it's returned on the 06z operational again, with twin PVs over Canada and Siberia.

EC hasn't shown signs of splitting yet, but both it and the GFS ops have been showing a warming over Scandi which displaces the PV from Greenland over into N America by day 10.

Combine this with the MJO moving through 7 and into 8 over the next few weeks and we may see a better chance of HLB building from the Atlantic to the N and NE over Scandi later this month.

Interesting times ahead ... even if there isn't a split in the PV, if there is, then we could see cold and snow opportunities extending into early March too.

The thing is though the ECM isn't really far into range yet, but have you access to any extended ECM eps strat data?, that would help clear up whether its just another GFS tease or any real credence, the fact that its prevalent on the GEFS must give it some weight.

[frosty ground]

Just now, Steve Murr said:

Didn’t say you were per say -but a whole page this morning of mild ramping when you have the best output in front of us for 5-6 years.. Even the pellet from Shropshire   Saying rain from the NW in -10c air - lol

says it all really.

anyway back on topic.

I just read that almost fell of my chair with laughter........ He thinks its a standard Toppler.

 yesterdays 18z (You can see the Mild sector on the 3rd
today's (short Ensembles) show the mild sector being eroded.
 

[feb1991blizzard]

Stretching at 1mb on ECM.

[Nick F]

3 minutes ago, feb1991blizzard said:

The thing is though the ECM isn't really far into range yet, but have you access to any extended ECM eps strat data?, that would help clear up whether its just another GFS tease or any real credence, the fact that its prevalent on the GEFS must give it some weight.

Unfortunately only have access to ECMWF deterministic strat charts to day 10. So will have to wait and see if the GFS is on to something, the GFS ops have been all over the place recently with the strat, though seem to be finally converging on idea of warming over Scandi and displacement of PV into N America at least, the split is uncertain for now though as it keeps appearing and disappearing with subsequent runs.

[Man With Beard]

And this is the mean chart...

 

[WalsallWeather123]

12 minutes ago, Man With Beard said:

And this is the mean chart...

 

-8 uppers aren't even that cold. 3 degrees for lower ground. Marginal for snow 

[chionomaniac]

Generally when cold is shown in FI it gets watered down by the time it arrives if at arrives at all. However...... when a cold spell pops up in the medium range then upgrades and downgrades tend to occur run by run but with far less watering down.

MJO, strat, cold pool all look like coming together for once - and when you have these on board then upgrades are possible.

[mulzy]

4 minutes ago, WalsallWeather123 said:

-8 uppers aren't even that cold. 3 degrees for lower ground. Marginal for snow 

A -8 uppers mean chart should never be sniffed at, particularly out at day 6/7.  You may still be right and things may go the way of the pear with regards a cold and wintry spell.  However, with the data/models that are available to us mere amateurs, I would say the *probability* of an upcoming cold spell is significantly greater than 50%.  

Time will tell as ever!

Anyway the 6z GEFS were a big upgrade on the 0z set.  I quite like P5!

[jacke]

A watcher for a long time and my first post which is not model related.  However seeing some of the posts this morning moderator please allow. To TEITS, a speedy recovery, I enjoy your posts.  I wonder whether you was treated at Peterborough City Hospital Intensive Care?  I am a volunteer in the unit.  Just on the current  model discussion I was about for the 1963 winter.  Not the technology then but the realization of what was to come was only picked up at about 72hrs.

 

 

 

[weirpig]

11 minutes ago, WalsallWeather123 said:

-8 uppers aren't even that cold. 3 degrees for lower ground. Marginal for snow 

-8 uppers  which looking at the mean  shows from a easterly quarter  not cold?.  It can snow in that scenario from -2 uppers  Im a little confused.  you may be right in the downgrading of this event/period  however you analysis of the charts provided shows that with all due respect a pop into the learning thread may help.

[Alexis]

17 minutes ago, WalsallWeather123 said:

-8 uppers aren't even that cold. 3 degrees for lower ground. Marginal for snow 

-8 is what I regard as exactly what is required for snow. It's -6/-7 uppers that are hit and miss in my experience.

[johnholmes]

18 minutes ago, WalsallWeather123 said:

-8 uppers aren't even that cold. 3 degrees for lower ground. Marginal for snow 

I am not quite sure where your idea on that comes from? Snow can fall with surface values at 3 C and certainly with the 850 mb at -8 C, even higher at 850 mb.

[SMU]

1 minute ago, WalsallWeather123 said:

Forget that I quoted that chart. Just generally talking about -8 uppers meaning marginal conditions. Not guaranteed a widespread snow event 

That’s because you are using -8c over a maritime track-

The mean for Eng@156 is continental sourced with lower dewpoints & Theta E is around 6-8c which is spot on.

[Yarmy]

I like Liam Dutton, but the latest GFS inter run comparison does not tally with this assessment regarding the inferior performance of the 6z and 18z runs:

The stuff about fewer observations is not true either. I recommend reading this thread, especially the post from dtk, a meteorologist working at NCEP:

https://www.americanwx.com/bb/topic/32149-gfs-12z-and-0z-runs-compared-to-6z-and-18z-runs/

The model as a whole of course, is consistently outperformed by the Euros.

 

 

Edited January 31, 2018 by Yarmy