Model output discussions pm 31/12/15

[Dancerwithwings]

Wouldn't blame the BBC presenters getting a little excited when looking at the UKMO 144h

Just a shame we can't see the 850hpa data.

Q...Does anyone know why the UKMO stopped giving out the 850hpa data at 144h or even 72h,96h and 120h for that matter

[Snowman.]

Lovely ensembles 

Edited January 5, 2016 by SN0WM4N

[booferking]

It seems we got to this stage yesterday then it went pear shape lets hope the ECM backs the UKMO then we can move on and its just a matter how long this cold spell will last to confirm...

[fromey]

Hi all.

just to add a little something that I have read throughout the day and that is few of the met people over in the USA aren't liking the GFS at the moment and are using the ecm, U.K. Met and some Canadian model I don't know if Nick has read something similar or can shead any light on this

 

fromey 

[carinthian]

6 minutes ago, Dancerwithwings said:

Wouldn't blame the BBC presenters getting a little excited when looking at the UKMO 144h

Just a shame we can't see the 850hpa data.

Q...Does anyone know why the UKMO stopped giving out the 850hpa data at 144h or even 72h,96h and 120h for that matter

The data we have just seen from our portal service goes for a substantial snow event early /middle part of next week in the Alps with widespread lower uppers with some depth, which I assume would be Arctic sourced airmass. Looks encouraging news this evening for many snow starved citizens of the British Isles.

Edited January 5, 2016 by carinthian

[Cloud 10]

Ensemble  number 8 provides the "black hole" of the winter.

 

[nick sussex]

3 minutes ago, Dancerwithwings said:

Wouldn't blame the BBC presenters getting a little excited when looking at the UKMO 144h

Just a shame we can't see the 850hpa data.

Q...Does anyone know why the UKMO stopped giving out the 850hpa data at 144h or even 72h,96h and 120h for that matter

Roughly that looks like 850's of -8  around the Midlands and - 10 towards northern Scotland. Snow likely on the northern flank of that low at T144hrs.

[Methuselah]

When does the NAVGEM come out?

[IDO]

Looking at the GEFS and the op is clearly non-representative of it's run; probably the worst run (for cold) out of the group, apart from if you live in the US and its a killer cold run throughout:

At D8:   w1 & w2   w3 & w4:  

Though the control is rather uninspiring as well. The CFS weekly's have performed a volte-face^^^

Still little agreement how that Arctic block will mix with any Rossby Waves in the NH? But whilst it meanders around in the general Arctic region it should provide opportunities for further links with Greenland and the recurring Atlantic Ridge. The CFS hinting at that. 

The cold air getting to the south during D7 on the GEFS and trending to remain below the seasonal average for the rest of the run. 

     Clusters at D8: 

2m Temps look cool in London; with the chances of snow, although still low, showing some life, something we haven't seen much this winter. Hopefully its a case of the ensembles dragging the op down to the correct solution. Clusters show four different varieties, all viable, so there remains entropy at that range from the GEFS (and I assume ECM). Tomorrow 12z's may be a bit more helpful in how this will unfold.

 

[Cheshire Freeze]

1 minute ago, nick sussex said:

Roughly that looks like 850's of -8  around the Midlands and - 10 towards northern Scotland. Snow likely on the northern flank of that low at T144hrs.

However not one ensemble member of the GEFS gets anywhere near that at day 6. GEFS bring the cold in later. There's going to have to be a monumental flip in that tight ensemble grouping to get anywhere near that. Will be interesting if the ECM picks the same solution.

[nick sussex]

7 minutes ago, CreweCold said:

However not one ensemble member of the GEFS gets anywhere near that at day 6. GEFS bring the cold in later. There's going to have to be a monumental flip in that tight ensemble grouping to get anywhere near that. Will be interesting if the ECM picks the same solution.

I'm using this guide for the 850's. It comes in handy with the UKMO which for some reason thinks its 850's are top secret and a matter of national security! lol

 

Roughly for the Midlands 1000 by 522 = -8.5  850 value.

Edited January 5, 2016 by nick sussex

[SMU]

So another hour before ECM - 1 hour spare

UKMO tonight Is good, at 168 we still don't squeeze much ridging up towards the arctic but some ridging would have the net effect of slowing the jet down-

Also a bonus MAY be that the even though the block may collapse it could hold back far enough west that we stay in the cold & snowy unsettled flow ( that is very rare)

 

anyway what I thought id do is show as many Greenland Highs & how they develop from the archives - & show they don't come from this set up-

There hasn't been many ( IF ANY ) - that have come from a mid latitude Canadian block- the base area to look is a scandi retrograde or a resurgent azores high - ( the ECM I think yesterday had one at day 10- with the tell tail circulation pattern  -( see my last pic )

Theres nothing to be unduly unhappy tonight- we aren't getting the holy grail to start with but as said above as long as we get some transient heights into western Greenland ( the more the merrier ) then the jet will slow down & hopefully dive SE - we will then be left with a polar high & an azores ridge that may have another go of driving North....

 

 

1955 scandi retrograde

1955 feb azores ridge

Jan 1958 - Azores High

 

December 1962 - Azores & Scandi retrograde ( the best )

1968 - Azores ridge

1970 - azores high

more recently...

JAN 2004 thundersnow

March 2006 Scandi & azores High retrograde

 

 

 

2009 - Uk Azores High

 

2010 the azores & scandi retrograde THE DADDY

ECM 12z yesterday... chances chances....

 

 

 

 

[Mark Neal.]

Looking at the UKMO 144hr chart from a UK viewpoint

. 

-6c uppers for Southern England based on that, Agree with Nick Sussex a pain not having access to uppers for UKMO so a case that chart comes in handy!

Edited January 5, 2016 by Mark N

[Cheshire Freeze]

2 minutes ago, nick sussex said:

I'm using this guide for the 850's. It comes in handy with the UKMO which for some reason thinks its 850's are top secret and a matter of national security! lol

 

 

 

Oh, I wasn't questioning the validity of your claims of the uppers Nick- Just pointing out how unlikely that day 6 chart is if we're using it in context of the GEFS. I'd say it's about 7C lower at 850s level than any GEFS pert for that time.

[nick sussex]

1 minute ago, CreweCold said:

Oh, I wasn't questioning the validity of your claims of the uppers Nick- Just pointing out how unlikely that day 6 chart is if we're using it in context of the GEFS. I'd say it's about 7C lower at 850s level than any GEFS pert for that time.

Yes I know I didn't take that inference! lol Agreed though its strange that none of the GEFS come anywhere close to that. Perhaps that guides dodgy! Doing it by hand is a pain, so I just use that guide!

[Dancerwithwings]

8 minutes ago, nick sussex said:

I'm using this guide for the 850's. It comes in handy with the UKMO which for some reason thinks its 850's are top secret and a matter of national security! lol

 

Roughly for the Midlands 1000 by 522 = -8.5  850 value.

Thanks, best desk top background ever...Well it is now

[Methuselah]

I think that our collective reasoning, on model-predicted snow-chances, has evolved? 

Back in 2003, it seemed that the 528 dam line was the Holy Grail; but no more: IMO (taking variables like distance from the coast, RH values, even wind speed, into consideration) an 850 temp of -8 to -10C is the thing to look for? In Jan, 2010, Inverness had sleet with 850s of -9C??

[lorenzo]

Finding the 'tableaux' setting in the ensembles useful just now when looking for a quick glance across the ENS suite vs. clicking through Perturbations.

http://www.meteociel.fr/modeles/gefs.php?table=1

Then click Carte Europe or Carte Monde to extend the map and click where you want a chart for.

The example chart attached is for 850hPa temps across somewhere round about my location, but easy to do the same for your own location or wherever in the world you want to look at. Again, handy for overall trends, and makes exceptional charts easier to find quickly.

 

 

[tight isobar]

@96hrs..ecm..

The Canadian lobe is imploding! 

And weakening in volatility. ..

Where's this going. ..

Anyone's guess! 

[Cheshire Freeze]

A lot more realistic 144 uppers chart from the ECM in my opinion....

Synoptic chart not as good as UKMO (obv). Let's see where it goes from here

 

Edited January 5, 2016 by CreweCold

[tight isobar]

Tbf..its looking like an A☆

For mr Steve murr....

With interest @the Canadian lobe granted. ..but attention turned to the east format. ..going forward. 

[booferking]

So there we have it ECM & GFS going the slower route..

[Eskimo]

Just now, booferking said:

So there we have it ECM & GFS going the slower route..

Tortoise and the hare, my friend. 

[shaky]

5 minutes ago, CreweCold said:

A lot more realistic 144 uppers chart from the ECM in my opinion....

Synoptic chart not as good as UKMO (obv). Let's see where it goes from here

 

Dont be fooled we could get copious amount of snow from a chart like that!!thicknesses i assume would be really low and with a slack flow it will help!!

[booferking]

1 minute ago, PerfectStorm said:

Tortoise and the hare, my friend. 

Hopefully.