Model Output Discussion - 05/01/2016 18z onwards

[Geordiesnow]

8 minutes ago, Mark N said:

I reckon even Johm Hammomd took a look at the 12z GFS  

@bbcweather - Computer models very confident of much colder weather next week. Exactly when it arrives is another matter... John H

As I say, if the UKMO is right, then its more likely the cold will arrive quicker whereas with the GFS its a bit of waiting game for the cold air to come down so hopefully the ECM will back the UKMO again on this when it comes out shortly. 

For all the talk of the GFS run, I think the UKMO is the better run in the short to medium term, trigger low clears eastwards quicker(Which btw may potentially give snowfall to Southern Scotland/Northern parts of England) and the floodgates open much quicker and the flow looks stronger and more likely colder than the GFS. Where it goes after that is a bit uncertain but it looks a decent Atlantic block there and you would not thought it would go the way of the ECM run. 

[ALL ABOARD]

I give you perturbation 7!!!!

   

 

anyone want to raise me? in all fairness though scrolling through the ensembles and there are a wide variety of options. Most of them takes us into the freezer though and keeps us there!!!!

[heccygabber]

40 minutes ago, Harsh Climate said:

As great as this run is it offers little snow for 90-95% of the country! With coastal areas/northern scotland/northern ireland getting a pasting. 

 

What's great about this run is the potential and how it may develop though.

People do live in coastal areas/northern Scotland and northern Ireland, you know

[knocker]

21 minutes ago, fat chad said:

True polar lows are extremely rare..so I have been told on here.

They are indeed and don't just require an unstable northerly.

POLAR LOW - METEOROLOGICAL PHYSICAL BACKGROUND

http://rammb.cira.colostate.edu/wmovl/vrl/tutorials/satmanu-eumetsat/SatManu/CMs/PL/backgr.htm

 

[dbaloo]

ECM tonight could break the internet if it goes the way the majority in here want it to!been great reading the last few days in this thread!

[mushymanrob]

.... if its too good to be true, it probably is.

(gfs).

[Troubleatmill]

 

8 minutes ago, heccygabber said:

50 minutes ago, Harsh Climate said:

As great as this run is it offers little snow for 90-95% of the country! With coastal areas/northern scotland/northern ireland getting a pasting. 

 

What's great about this run is the potential and how it may develop though.

People do live in coastal areas/northern Scotland and northern Ireland, you know

Indeed, also do you remember this and the satellite photo of the uk that followed  

 

 

 

Edited January 6, 2016 by Nicholas B

[rory o gorman]

Given the SST'S current and the 500mb to 850mb temps,  any 700 mb shortwaves ejecting south would be highly convective and provide quite a bit of snow even inland. Again the chance's of  polar low development in the 12z output  seems favorable . ECM is key , often seeing eastern seaboard amplification differently.  Again we wait... 

[MR EXTREMES]

well well the mjo is certainly raised its game although the phase 8 nick s was talking about !could be the reason why the gem in the later stages shows the topple of the atlantic high.

and the gfs if it went further out could possibly be showing a similar outcome toppling heights.

 

but as the cold  is embedded if it toppled over the uk it would likely keep the uk cold bottled up.

it will be interesting to see how negative the ao and nao will go.

but overall cold spell looks good but not a classic 09/10 just yet,

but id be very surprised if we don't have another cold shot in feb.

but anyway certainly looking better for uk wintery weather.

 

Edited January 6, 2016 by emotional rollercoaster

[Day 10]

Before the ECM after the ECM

[Polar Maritime]

With the ECM coming up 'and in any case' can we please all try to keep on topic as it keeps the thread clean, And is much easy'r for members/guests to read. 

 

Edited January 6, 2016 by Polar Maritime

[Yorlum11]

 

Hugo is impressed!

Edited January 6, 2016 by Yorlum11

[Troubleatmill]

12z ensembles none too shabby!

Edited January 6, 2016 by Nicholas B

[I remember Atlantic 252]

This looks really good for my location, FI on UKMO, angled well for snow showers, assume 850's around -8

[Nick F]

The 12z GFS really highlights the need to not to be too swayed by the swings of the x4 operationals each day. Yesterday some were getting despondent because there was little amplification on the GFS ops over the N Atlantic and so Greenland was covered in lower heights and we saw a northerly toppler - whilst the EPS mean was indicating a strong signal for N Atlantic to N Pole ridge right up to day 15. 

The 12z op maybe overplaying the amplification, we don't know, but even the less amplified ops still had the UK under a cold Am then Pm flow for several days, with then the potential, which has been consistently showed, for high pressure to build in from the W or SW locking in cold at the surface, so it's looking positive even if we end up less amplified - as there could be northerly re-loads.

Been no grumbles from me these last few days despite the rollercoaster of the GFS - as the EPS mean has been steadfast over the Atlantic/Greenland block.

But glad everyone is very upbeat now in light of the 12z GFS - does look full of wintry potential and a synoptic scenario we haven't seen for a long while, probably as far back as winter 12/13?

Edited January 6, 2016 by Nick F

[fromey]

with all this going on with out a SSW, look what Matt Hugo just posted about the strat final nail in the PV coffin??

[Troubleatmill]

1 minute ago, fromey said:

with all this going on with out a SSW, look what Matt Hugo just posted about the strat final nail in the PV coffin??

Well its been an amazing PV this winter, but it is now getting utterly carpet bombed!!

[fromey]

6 minutes ago, Nicholas B said:

Well its been an amazing PV this winter, but it is now getting utterly carpet bombed!!

I think nuked is more like it!!! 

question 

, what further effects would a strat warming on that scale have on what we are seeing now, is it already taking it into account??

[dragonfalls]

The models are showing more blue any chance those purples colours will make it to the UK I no its early to say is this laying the blocks for a brutal February' 

[I remember Atlantic 252]

Tuesday proper cold arrives on GFS 12Z, my location only sees snow with the dark blues

[booferking]

Yep and ECM has cold air in quicker like UKMO snow falling in the north from Saturday-Sunday nice.

[Mr Sleet]

Although a big improvement in the models for cold, this set up gives us the wishbone effect with snow showers really limited to far northern and coastal areas. 

For those away from the coasts and in the southern half of the Uk,we'll have to hope for some disturbances running down the country to deliver anything. 

[chris55]

3 hours ago, Steve Murr said:

Updated AO suite from the 00z 

EPIC a la 2009 & 2010

s

 

Yes Steve looks off the scale! 

Also the last time I remember a black hole anomaly like this was in the lead up to DEC 2010!!

 

 

[That ECM]

For any newbies, not suggesting I am an expert, might want to look at the 850s via NH profile and watch the warm air go north up the east of America and the cold come down over the uk. Something nick has been talking about previously.

[Geordiesnow]

Well at least the ECM is following the UKMO in sending that low eastwards therefore the floodgates open quicker than the GFS run, this run upto 120 hours does look a little bit more amplified than this morning's runs also. 

Either way, I'm happy the ECM is maintaining the trend of shifting the trigger low quicker eastwards, I rather get the cold in than having any delays to it. 

Edit: Yep, the ECM is backtracking at 144 hours, its most certainly is amplified and there is no shortwave spoiler in the medium term on this run, cold lovers will be pleased tonight! 

Edited January 6, 2016 by Geordiesnow