Cold hunt - models and chat

[Leon1]

1 minute ago, TomW said:

10th December

It snowed here for about 6 hours but none settled. Just a mile up the road there was about 10cm. That M4 snow line will be the death of me!

[MattStoke]

5 minutes ago, Spah1 said:

Can we just all agree that the track of the low next week will change every run so I don’t have to read every post saying ‘subject to change’ etc. 

People are scared to death to analyse a chart in the anticipation someone will tell them it may change on the next run. 

WE ALL KNOW IT WILL CHANGE RUN TO RUN. 

We don’t have to add that caveat to every dam post. 

Kind of do given that people get sniped at if they don’t...

[Wilxy]

1 minute ago, Leon1 said:

It snowed here for about 6 hours but none settled. Just a mile up the road there was about 10cm. That M4 snow line will be the death of me!

It was rain here all morning then turned to snow around midday but it never got heavy enough to settle on the ground as it was to wet

[snowbob]

16 minutes ago, Steve Murr said:

Yes we have only been been here a few times in the last 10 years & most / nearly all have drifted away south-

The most recent touch down was March 13 for the extreme south & the channel Isl..

Either way it looks good at this stage....

Quick question if it did pull away into France would that drag down colder uppers

[WhiteFox]

9 minutes ago, kold weather said:

Definate a north trend on that O for Tuesday, which I think may continue a little further yet as the models key into a stronger system. I expect it to be broadly similar to then UKMO/GFS FV3, but a little further north , also may be VERY marginal by the coast IF that does happen. Isn't showing on the models yet however bar maybe 2-3 ensemble members.

Matt - to be honest, if we get snow on Tuesday, you northern lot are welcome to your dumping of snow then.

Steve - I think this will be the rare exception where it will trend ever more northwards + stronger. That's what happened with this weekends LP for example.

It's a difficult one to call. Obviously a deeper low would naturally track further north and east, buy in these situtations a difference of 100 miles is enormous interns of PPN type and global models at this range will struggle with the details. Once this gets into high resolution model range we can really start to analyse in more detail.

Just a quick note on the overall pattern; I noted that yesterday in the 500mb CPC discussion they gave a confidence of 5/5 for both the 6-10 and 8-15 day 500mb pressure anomaly charts. US forecasters clearly think that the pattern shown is well represented across models, but of course we have to expect variations in the surface level analysis. It is these variations to which we now turn our attention with respect to snow possibilities in the shorter term: eyes down for a snow chase!

[MidnightSnow]

3 minutes ago, Leon1 said:

It snowed here for about 6 hours but none settled. Just a mile up the road there was about 10cm. That M4 snow line will be the death of me!

Just Youtube'd the MetO forecast for 10th December 2017 and know why I wiped it from my memory. Missed out big time by just a few miles.

[Scandinavian High.]

9 minutes ago, MattStoke said:

Worse for southern and central areas of England and for Wales on the GFSP with regards to Thursday’s system. A wintry mix.

Snow for Northern England, Scotland and Northern Ireland.

Will change many times between now and then, of course. Especially given that even Tuesday is far from resolved.

Yes  I agree Tuesday low isn’t done  yet at the minute looking great for the south. Thursday system is long way off we could see this system trended south bringing southern England back in to more snow I expect more changes to come .

[kold weather]

10 minutes ago, Mike Poole said:

ARPEGE take on Tuesday nights low at T96, 0z run:

850s good for marginal snow, this could be a great event for parts of the country yet to be determined.

Interesting but its evolving a different pattern (AGAIN!) where the low pressure to the north takes over, which obviously keeps the south in the 'milder' side of the low, though of course its all relative. Whilst all the other models develop the low to our south which keeps the south on the right side of the low which means we xoyuyld afford the marginal 850hpas.

Indeed if it is a channel runner, -1/2C would be ok for snow on the north side of the low.

Edited January 26, 2019 by kold weather

[TEITS]

Just add my thoughts with regards to snowfall next week. This is based on a combination of all model runs and instinct.

Tues low pressure system. Sadly im not convinced this will affect much of the UK. At the moment I believe this will mainly affect France with the small chance of extreme S counties.

End of the week. Expecting this to continue to track further SE than currently modelled.

Just add ensembles for the low on Tues are in my opinion useless.

[Frosty.]

What great charts for next midweek on the Gfs 6z operational..winter..we have lift-off!! 

[kold weather]

12 minutes ago, IDO said:

Ensembles:

Up to 50% from 35% chance of snow London, back edge tomorrow morning; suspect percentage increase further north, compared 0z.

Consistent 60-70% both 0z and 06z for snow from the first low Tuesday.

Too far out for consistency re Thursday low due to timing issues. But the opportunity remains good.

A reasonable trend, but fine margins all the same.

Yeah that's true, I quite like 60-70% chance, especially as I think the models are under-estimating the strength even as it is, so that's good to see they are that high.

Anyway as you say there is a lot of set-ups out there.

The first seeds of formation come off Mexico in about 6-12hrs and then feed up the frontal boundary before forming a low in the Bahamas region. I think that is when we should state to see something resembling agreement.

[BlackburnChris]

975 low on 6z Para . 1050 high on 00Z . Lots to sort out long term .

 

              

[SMU]

Here is the 10th December V the UKMO 96 chart- 

The track for 10 Dec is probably just about within the cone !

[Djdazzle]

Just now, BlackburnChris said:

975 low on 6z Para . 1050 high on 00Z . Lots to sort out long term .

 

              

If ever there was an advert for why FI is FI, that is it!

[kold weather]

6 minutes ago, TEITS said:

Just add my thoughts with regards to snowfall next week. This is based on a combination of all model runs and instinct.

Tues low pressure system. Sadly im not convinced this will affect much of the UK. At the moment I believe this will mainly affect France with the small chance of extreme S counties.

End of the week. Expecting this to continue to track further SE than currently modelled.

Just add ensembles for the low on Tues are in my opinion useless.

Yeah that is certainly what history would suggest.

However I've got a sneaky feeling Tuesday's system is going be that 1 out of 10 that trends northwards + stronger. Partly because I think its going to be stronger than currently expected and north + stronger due to the trend that happened to todays LP, which at one point came from a similar geographical location and look where it is forecasted now! I'm a bit of a fan of set-ups that try to repeat themselves so close to each other.

 

[Kentspur]

7 minutes ago, abbie123 said:

Yes  I agree Tuesday low isn’t done  yet at the minute looking great for the south. Thursday system is long way off we could see this system trended south bringing southern England back in to more snow I expect more changes to come .

 

2 minutes ago, Steve Murr said:

Here is the 10th December V the UKMO 96 chart- 

The track for 10 Dec is probably just about within the cone !

Assuming it ends up a similar track wouldn't it mean more chance of snow for those south of the M4 based upon the fact were in mid winter now?

[Snowman.]

5 minutes ago, BlackburnChris said:

975 low on 6z Para . 1050 high on 00Z . Lots to sort out long term .

 

              

Para looks at odds FI with both the GEFS and ENS. Its 0z run looks closer to the mark maybe a little too far south.

Expect heights to be placed across the Scandi/Svalbard area.

Edited January 26, 2019 by Snowman.

[BlackburnChris]

Just now, Djdazzle said:

If ever there was an advert for why FI is FI, that is it!

Lol , I Know . Looking for signs of changes in the NH . FI is very early in the runs at the moment.

[I remember Atlantic 252]

Another legendary one, hope Thursdays low ends up something like this! modelled similar on GFS and UKMO

[feb1991blizzard]

16 minutes ago, TEITS said:

Just add my thoughts with regards to snowfall next week. This is based on a combination of all model runs and instinct.

Tues low pressure system. Sadly im not convinced this will affect much of the UK. At the moment I believe this will mainly affect France with the small chance of extreme S counties.

End of the week. Expecting this to continue to track further SE than currently modelled.

Just add ensembles for the low on Tues are in my opinion useless.

The Met Office agree, they did a video on it yesterday, The Northern most extreme would of struggled to reach you or me.

[swfc]

5 minutes ago, BlackburnChris said:

Lol , I Know . Looking for signs of changes in the NH . FI is very early in the runs at the moment.

It's not happening is it hence lack of comments but low gate is taking the headlines!!

[BLAST FROM THE PAST]

1 hour ago, Mike Poole said:

FV3 superb at T84 for the south, here

Illustrative snow depth at just T96

And yet we know there is still massive uncertainty even at this range.  12z runs should be fascinating!

Yes with regards to this I think we’ll have to get to t48....and then there could be further slight shifts that could make a difference to snow chances.   I think as I mentioned yesterday the itv weather / metO gleefully forecasting 5c 6c and 7c for my location Wed, Thurs, Fri........we’ll see.  Last Thurs was 1c on my golf course....max.

 

BFTP

[Scandinavian High.]

25 minutes ago, Kentspur said:

 

Assuming it ends up a similar track wouldn't it mean more chance of snow for those south of the M4 based upon the fact were in mid winter now?

At the minute southern england seems to be the zone at the minute that’s south of the m4 right across southern England but there is a lot to play for it could go down to to the wire a slight move north we could be wet rather then white but looking good at minute for the south 

Edited January 26, 2019 by abbie123

[kold weather]

5 minutes ago, BLAST FROM THE PAST said:

Yes with regards to this I think we’ll have to get to t48....and then there could be further slight shifts that could make a difference to snow chances.   I think as I mentioned yesterday the itv weather / metO gleefully forecasting 5c 6c and 7c for my location Wed, Thurs, Fri........we’ll see.  Last Thurs was 1c on my golf course....max.

 

BFTP

Yes I agree, though we should get a much better steer for how this will evolve once the frontal low near the Bahamas forms tomorrow evening. We will then have a real entity with which to be able to compare the modelled version with and we will see where the errors with the forecast lies. Also I think the Canadian low also forms tomorrow morning and so I'd think 12z Sunday shold be when things will really clear up and I expect 'broad' agreement by that point.

However, broad agreement in our neck of the woods can still make a big ole difference in terms of actual weather.

Edited January 26, 2019 by kold weather

[Disco_Stu]

I'm getting ready to duck once the toys start to be thrown from the prams again!

Edited January 26, 2019 by Disco_Stu