Winter Model Discussion 12Z 15/1/13 onwards.

[Matty M]

UKM 96hrs = somebody will be digging themselves out.

[Harsh Climate]

This is some serious upgrade guys and within a quite short 102h time frame too!!

[Panayiotis]

As expected the 12z has moved everything back to the way they were on the 00z as the 06z shifted everything east, I say this because selfishly im in the firing line!

[weather eater]

Starting to get concerned about Fri I have to get into Manchester for a scan in the morning and home by lunch time and somewhere looks increasingly likely to get a full on blizzard. 102hrs much less progressive than the 06z.

[Harsh Climate]

GFS almost identical to UKMO after all these days of gfs playing a very slow catch up.

If things pan out like this, the UKMO will have covered itself in true glory! Would be a huge coup for the met office

[Southern Storm]

undercut forces cold uppers back west, better 12z run, and happy with this as still hoping for a sig snow event here Friday (Extremely rare)

yes its a good run and I expect southward trend to continue up until the actual event.

Its been said many times before but models always underestimate blocks!

[Weathizard]

Ukmo at T96 looks fantastic for around London northwards to me surely even with that undercut would drag warm upper into the south? Some astonishing snow totals possible

And Im not an expert on this matter but is that Atlantic trough beginning to take a more negative orientation?

Edited January 15, 2013 by Weathizard

[fergieweather]

Can I just caution re posting / taking as gospel these raw (and often useless) GFS precip/snow probability maps at this juncture. The alogorithm used for these is pretty basic, and I never even bother with them.

A far better route to understanding (at least from GFS) the PPN type prospects for any given area, plus crucial nuances of boundary layer conditions as well as aloft, is to pick-up on the profile soundings plotted for any part of the globe via the excellent http://ready.arl.noaa.gov/READYcmet.php (we compare these here to our UKMO-GM/NAE tephigrams).

[Methuselah]

yes its a good run and I expect southward trend to continue up until the actual event.

Its been said many times before but models always underestimate blocks!

Except the ones back in February and December?

[Ali1977]

Noted IanF, however it still looks like more of a snowier chance that the 06z...I think!

[fergieweather]

Noted IanF, however it still looks like more of a snowier chance that the 06z...I think!

We are concerned. Just on blower to UKMO now. 6-12hrs snow possible parts of my area Fri. Not good.

[That ECM]

We are concerned. Just on blower to UKMO now. 6-12hrs snow possible parts of my area Fri. Not good.

Not good. Hopefully they will upgrade it to 24hrs!!!!!!"

[Anti-Mild]

That UKMO is amazing for the weekend, although it's almost getting beyond the "fun" stage and into "serious" territory.

From a personal perspective, I'm supposed to be taking a trip to Cardiff from the NE on Friday lunchtime but I anticipate a cancellation!!

Edit: Just seen the +120.......

Edited January 15, 2013 by Anti-Mild

[bluearmy]

some astonishingly low thicknesses in the mid atlantic T138 courtesy of the discarded chunk of canadian vortex

[danm]

We are concerned. Just on blower to UKMO now. 6-12hrs snow possible parts of my area Fri. Not good.

Hi Ian, how far east do you think the system will move?

[Rob K]

A far better route to understanding (at least from GFS) the PPN type prospects for any given area, plus crucial nuances of boundary layer conditions as well as aloft, is to pick-up on the profile soundings plotted for any part of the globe via the excellent http://ready.arl.noa...v/READYcmet.php (we compare these here to our UKMO-GM/NAE tephigrams).

Of course, Ian, but does the data the Met Office is working with also support a disruptive spell for much of the country on Friday and Saturday, as we are seeing in GFS, GME and raw UKMO output?

Edit: sorry just saw your previous post. Thanks.

Edited January 15, 2013 by Rob K

[Tim Bland]

Wow... Fronts bringing snow from the south west on Fri / sat then again on Sun / mon on this run. somehwere could be seriously burried and hats off to the UKMO for sticking to its guns while other models caught up... assuming we are almost there for the correct synoptics at day 5 that is. NAE's reputation is possibly about to take a beating afer its latest output as well.

[nick sussex]

We are concerned. Just on blower to UKMO now. 6-12hrs snow possible parts of my area Fri. Not good.

Thats quite funny Ian because not good for you will be met with hysteria in here!

I think you know the score by now! If I was working for the UKMO this would have been a good time to take a vacation as the forecast is likely to lead to alot of grey hair.

I suppose you've seen many of these set ups in the past as have many of the longstanding members in here, you don't get more complex than this, a nightmare to forecast no matter how many great computers and data you have at hand.

[fergieweather]

However - the potentially errant 12z NAE prog for Thurs is a possible major spoiler and albeit we have it discounted for now..... watch this space. Fri considered 'low probability, severe impact' event currently and we need greater continuity through next 24hrs.

[chionomaniac]

Just in case the cold pool is waning - reinforcements are on the way:

Edited January 15, 2013 by chionomaniac

[Troubleatmill]

We are concerned. Just on blower to UKMO now. 6-12hrs snow possible parts of my area Fri. Not good.

Obviously for us on here its fantastic as thats our mentality , but from yours and your collegues point of view i see where the 'not good' comes in Ian

Edited January 15, 2013 by Nick JB

[WhiteFox]

hings pan out like this, the UKMO will have covered itself in true glory! Would be a huge coup for the met office

I don't think they will be bothered; the UK Met Office model regularly beats the GFS in verification stats, hence why they have been able to sell it to Japan and Australia I guess!

[bluearmy]

if ukmo raw is anything like accurate, there will be a fair few occlusions on the faxes this evening and working out if snow turns to rain behind will be a tricky one to work out

[The Northern Ramper]

We are concerned. Just on blower to UKMO now. 6-12hrs snow possible parts of my area Fri. Not good.

You probably get tired of people asking but it would be invaluable if you could give us Exeters thoughts on who they think will be hit by this.

How far north and East etc....

[Panayiotis]

Ye Chiono, high pressure/block persisting in the north and we still have the easterly component on Monday!