Winter Model Discussion - 12/01/13 06z Onwards

[kev238]

My understanding is that the first band is a separate band that dies as it spreads south east, with a second spreading from the north that should come into range of nae this afternoon at plus 48 hours. Certainly BBC forecast shows 2 separate bands

The 6z nae showed upe to 6 am on Monday so the 12 z nae brings us up to midday on Monday so should see more info on the second more substantial band of snow; at least thatnis what I am expecting to see

[The Weather Dragon]

Please can someone advise - I do have some considerable experience regarding models etc. Why do GFS temperature charts for my area (Pembrokeshire SWWales) always overestimate min/ max temps. Let me give you an example - midday today GFS 8c, actual temp 3c - this also happens with nighttime minima

[swfc]

My understanding is that the first band is a separate band that dies as it spreads south east, with a second spreading from the north that should come into range of nae this afternoon at plus 48 hours. Certainly BBC forecast shows 2 separate bands

The 6z nae showed upe to 6 am on Monday so the 12 z nae brings us up to midday on Monday so should see more info on the second more substantial band of snow; at least thatnis what I am expecting to see

you are correct.The first light band comes threw in the early hours then the more active front passes threw during the day

[SnowBallz]

Now out to +36:

[Summer Sun]

The snow for Monday is a changing situation as two bands of rain / snow cross the UK band 1 clears during the early hours band 2 lasts most of the day

[Slowpoke]

Now out to +36:

As I was expecting on the 12z, the whole region should see some of the white stuff tomorrow afternoon/evening

[Harsh Climate]

Now out to +36:

I'm hoping that's not mondays event being progged a lot earlier than first thought! Hate it when my snow comes through the night and I miss seing it fall.

[Hotspur62]

Looks like we are going to have a cold week with snow potential for most of the UK,but Eastern side favoured more (if i have read data correctly).Although not cross model agreement,it does appear that temps will on whole be well below average and if 2nd SSW occurs (and looked on their thread) things look even more promising for late Jan into early Feb for cold lovers.

From IMBY perspective things are looking a bit marginal for snow on Monday according to latest reports and look forward to IF's comments shortly.It would only take a slight upgrade and then all those South of London will be happy again.

Very exiting times me thinks and hopefully we will all be waking upto Winter wonderlands on Mon/Tues!!

[Panayiotis]

I'm hoping that's not mondays event being progged a lot earlier than first thought! Hate it when my snow comes through the night and I miss seing it fall.

Be careful what you wish for, If it comes in the day, the uppers/dew point may not be cold enough for snow!

[swfc]

Anyway back to the models"cough".Will gfs upgrade on the 12z or buckle to the atlantics assault?lol.Id go with a similar run to the o6z but with the atlantic making slight inroads.just my opinion like.

[Harsh Climate]

There are 2 bands of rain / snow coming don't worry! Band 2 will be more prolonged and significant

That's ok then , just thought the first band later sunday would be patchy/decaying, but hey I will take this then if that second band comes on monday

[IDO]

Midday Monday:

[Methuselah]

Anyway back to the models"cough".Will gfs upgrade on the 12z or buckle to the atlantics assault?lol.Id go with a similar run to the o6z but with the atlantic making slight inroads.just my opinion like.

You pre-empted me, swfc!

As the man says: back to the models - keep the NIMBY posts for the NIMBY threads?

[SnowBallz]

Midday Monday:

Yep, so 12pm Monday.

This would be the first front fragmenting as it transitions south - as expected/forecast. The second front then passes through behind it, which I don't believe is within the NAE scope yet.

[kev238]

Must admit I was expecting to see more evidence of a new band on the 48 hours nae, pushing in from the north west. It looks like the eastern side is intensifying up north though.

[The Eagle]

GME has changed - more toward UKMO at 72 hrs.

[bluearmy]

Nnm 06z has a different arrangement to nae for noon monday with the shortwave placement. As ever, details on precip placement and intensity will vary until at least 24 hours before the timescale you are looking to.

[J10]

Please can someone advise - I do have some considerable experience regarding models etc. Why do GFS temperature charts for my area (Pembrokeshire SWWales) always overestimate min/ max temps. Let me give you an example - midday today GFS 8c, actual temp 3c - this also happens with nighttime minima

That is because GFS over estimates the coastal influences of temperatures. Being an American model, coastal influences are not as important over there.

[MKN]

I think we need to hold off until this evening to get a full picture from the nae. +48 doesn't quite go far enough out to get a good idea of amounts possible

[Panayiotis]

Nnm 06z has a different arrangement to nae for noon monday with the shortwave placement. As ever, details on precip placement and intensity will vary until at least 24 hours before the timescale you are looking to.

Well maybe its because your comparing the 06z NNM to the 12z NAE? Edited January 12, 2013 by Panayiotis

[Methuselah]

Can we leave the hypothetical stuff about snow-depth and get back to the models, please?

[LomondSnowstorm]

In the shorter term the NAE increases the snow potential for Scotland and northern England, keeping the milder air west of the front meaning a big snowfall event for eastern Scotland and northern England:

followed by more at +48:

[bluearmy]

Well maybe its because your comparing the 06z NNM to the 12z NAE?

Checking same timeframe at noon but i take your point re initialisation data being more up to date on the 12z run. I have found nnm to be a pretty good tool wrt the nae

[Dean E]

Personally, I think the NAE is not seeing the snow cover that maybe present from band 1 tomorrow/Monday night.

Band 2 could actually also be a mostly snow event if there is snow cover already evident. The only concern is that the SW, away from higher ground, may miss out on the event.

SM

[J10]

The good news from NAE is that everything seems a little colder, certainly the colder air makes is further west quicker. The bad news is precipitation amounts seem to be smaller. So while some may get snow, it may not be as much as earlier runs suggested.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=-&VAR=rsum&HH=48&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

However I am sure that further runs will change this again.