Model Output Discussion - 8th December Onwards

[Gavin Hannah]

...And he's put the white behind the black...!! (at t.216 lol)

[gaia rules]

....and by T144 the 500mb chart shows the Scandavian upper high building again pushing the easterlies into Shetland....However that strong cold northerly blast from Eastern Canada needs to be switched off. Its giving the Atlantic too much energy.

[Isolated Frost]

ahhhh... what a beauty! Heavy snow for Scotland and northern England;

Keeps in line with the teleconnective signals- a slight shift in the dispersal of atlantic energy and the 18z suite provides a just outcome, interesting ensembles to come through I'm sure.. the extent of northern blocking is again notable and I'm sure FI will promote another stratospherically-backed transfer of mean heights westwards...

[Wilxy]

What a battle this could end up being by the end of the week, very exciting times.

[chionomaniac]

Another easterly chase likely to ensue!

Oh dear we're back to this again. Earlier I think we can move on from the possible snow apart from Scotland, the shortwave just refuses to get lost!

No major turnaround on that front, so its look east again, prozac at the ready!

You know I used to love easterlies now they're starting to get on my wick, can we just move onto a Greenland high!!!

There we are Nick.

[crimsonp]

anyone seen this yet?

[-uksnow-]

If we get an unstable and cold easterly flow, combined with the warm sea surface temperatures (SSTs) then there could be some pretty tasty convection.

After the farce of the last week I can't believe we're getting drawn into this again.

Cold dry air moving in an unstable flow over a relatively warm sea mean lots of convective snow.

Thank you thank you.

And i know this is FI, dont get me wrong, but can we really ignore the trend over the last several GFS' to bring in an easterly going northerly in the latter frames? Fits in with Chiono's thoughts beautifully

[Gavin Hannah]

....and by T144 the 500mb chart shows the Scandavian upper high building again pushing the easterlies into Shetland....However that strong cold northerly blast from Eastern Canada needs to be switched off. Its giving the Atlantic too much energy.

That's whats driving the LP south and elongating it I believe. Without it, we could end up with a Jet ploughing straight into us.

A Beasterly in time for XMAS!!!!!

Edited December 9, 2012 by IBringTheHammer

[95 Degrees]

If we get an unstable and cold easterly flow, combined with the warm sea surface temperatures (SSTs) then there could be some pretty tasty convection.

After the farce of the last week I can't believe we're getting drawn into this again.

I won't, the GFS 18z does indeed continue the slight upgrade for medium term cold weather, but after the last potential easterly faltered, I'm keeping expectations low.

[bobbydog]

sink the pink!

[Matty M]

Normal Service resumes. Chasing Easterlies in FI again

[Weathizard]

Taking the charts after 120-144 with a pinch of salt, if we concentrate on within this timeframe the trend to shift westwards of everything remains, if this continues it could lead anywhere, looking at the 144 chart we are not THAT far from something. I don't expect anything anymore, I'm not expecting this to go right but with the adjustments we are seeing every run, you just never know...

Even if we don't get a good outcome I love these battles between massively different pressure systems.

[Tom Quintavalle]

Normally i understand, but could you say this a little clearer please?

Hi eded,

Hope you dont mind Steve, a reasonable explanation of "Lake effect type snowfall".

Lake-effect snow or sea effect snow occurs in other countries, near large lakes or large sea areas. It also occurs in the regions of the Black Sea in Georgia and Turkey or the Adriatic Sea and Italy. For example, this type of precipitation which was generated by warmer Black Sea and colder air temperature, was seen in the Istanbul area between 24 and 26 January 2010. The snowfall in the eastern regions of the Black Sea is amplified by the orographic effect of the nearby Caucasus Mountains, often resulting in snowfall of several meters, especially at higher elevations. In Northern Europe, cold, dry air masses from Russia can blow over the Baltic Sea and cause heavy snow squalls on areas of the southern and eastern coasts of Sweden.

In the United Kingdom, easterly winds bringing cold continental air across the North Sea can lead to a similar phenomenon. Locally it is also known as "lake-effect snow" despite the snow coming in from the sea rather than a lake. {[fact}} Similarly during a north-westerly wind, snow showers can form coming in from the Liverpool Bay, coming down the Cheshire gap, causing snowfall in the West Midlands - this formation resulted in the white Christmas of 2004, in the area. A similar phenomenon can affect the city of Inverness in the Scottish Highlands, where cold north east winds cause heavy snow to form in the Moray Firth; this was the case with the White Hogmanay of 2009, which caused the street party to be cancelled. Northerly and north-westerly winds can cause the effect to occur over the Irish Sea and Bristol Channel feeding snow into south-west England and Eastern Ireland.

NetWeather radar image showing "lake-effect" snow over Kent and northeast England.

Since the North Sea is relatively warm (around 13 °C or 55.4 °F at the beginning of winter, typically 10 to 6 °C or 50 to 43 °F by the end), sufficiently cold air aloft can create significant snowfalls in a relatively short period of time. The best-known example occurred in January 1987, when record-breaking cold air (associated with an upper low) moved across the North Sea towards the UK. The end result was over a foot of snow for coastal areas, leading to communities being cut off for over a week. In recent years, lake-effect snow has been much lighter.

Regards,

Tom.

[Aiden2012]

is loving the 18z gfs woop hope it stays like that

[snowmadchrisuk]

any transistional snow next week though has vanished on this run , the over lying trend has been for the Mider air to creep in Wednesday well ahead of the PPN , Nice to see the blocking putting up a ight as we head towards +180 but looking at the charts its an odd run , as in 9 out of 10 runs that low would go straight through.....

[JP1972]

Oh Christ, we're off again aren't we.

Seat belt on and Colostomy bag emptied.

[Gavin Hannah]

Ahh, I'm off for the night. What a run!!!!

[Gibby]

Forget snow, Tonight's late faxes show some disturbing weather heading for the SW late in the week.

http://www.meteociel.fr/modeles/ukmo2.php?ech=96&carte=2000

http://www.meteociel.fr/modeles/ukmo2.php?ech=120&carte=2000

[EML Network]

If the GFS has support from even one member I will eat my hat after having dipped it into the Bog Of Eternal Stench.

Nice to see, but I'm not buying into it for one minute (As much as I so desperately want to)

[bluearmy]

Classic pub run ........ Remember the 18z was the run to set the agenda with the current west atlantic pattern which began this whole saga.

[nick sussex]

The latest fax charts for 96 and 120hrs:

http://www.meteociel.fr/ukmo/fax/fax96s.gif

http://www.meteociel.fr/ukmo/fax/fax120s.gif

The 120hrs is truly dreadful in terms of wind and rain, really not good for areas that have seen flooding recently.

[gaia rules]

who said that it takes three attempts to bring on an Easterly....I wont survive the stress if this one fizzles out nearer the time

[-uksnow-]

That's whats driving the LP south and elongating it I believe. Without it, we could end up with a Jet ploughing straight into us.

A Beasterly in time for XMAS!!!!!

or just a nice westerly :/

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=360&mode=0&carte=1

[snowice]

The beast lurks..........

I`am going to( MA ) Model annonymous for this addiction

Edited December 9, 2012 by snowice

[Chris K]

Forget snow, Tonight's late faxes show some disturbing weather heading for the SW late in the week.

http://www.meteociel...h=96&carte=2000

http://www.meteociel...=120&carte=2000

That certainly wouldn't be welcome.... as much as I love weather extremes, quite frankly more rain being belted at us certainly isnt needed and will make some peoples lives a misery for the run up to xmas. Especially here in the W/SW.