Winter/Spring 2013 (Model Output Discussion)

Wolfe_IRE

ZX7R wrote: »

After looking at most of the different model runs ,there defiantly looking like there will be a blocking ridge to the north west of Ireland during the start of December could bring us north, north east winds cold air ,worth watching to see what happens could be a bit of snow if the cold air from north mixes with air from south
I could be wrong with my reading of the models whats other peoples views

you're right re: ridging

All have high pressure to our nw/n. Don’t forget air circulates clockwise around HP so our air would be dragged from cooler NE. GFS has northerly on us.

ECM

JMA

GEM

gfs



uk met office monhtly forecast

Monday 26 November—Sunday 2 December

December beckons, settled weather coming?

Picking up with the unsettled theme at the start of the week, it begins with showers or longer spells of rain possible for the UK, with temperatures returning close to or a touch above average.
As the week progresses, there is a trend towards some parts of the country turning a little more settled, with temperatures falling to allow an increased risk of frost and icy patches. Any further rain or showers could then turn wintry over higher ground at times.

Monday 3 December—Sunday 16 December

Winter's here, and on balance it does looks cold

Even at this long timescale there is greater than average uncertainty for the first full fortnight of December. However, the balance of probability does point to this period being colder than average, which would lead to an increased risk of frost and fog.
However there still could be some rain at times, although this presently looks most like to occur over northwestern parts of the UK. This could, coupled with the colder-than-normal theme, lead to a risk of snow, mainly but not exclusively over high ground.

Tom Cruises Left Nut

This could, coupled with the colder-than-normal theme, lead to a risk of snow, mainly but not exclusively over high ground.

I think that line is very interesting, things may be afoot ! :pac:

BEASTERLY

This mornings output shows AO and NAO going negative, things starting to fall into place!

ZX7R

t|nt|n wrote: »

I think that line is very interesting, things may be afoot ! :pac:

Defiantly some interesting times on the chart reading front,Aldo it was interesting last year also with the beast from the east that never quite reached us but since September the long range charts have be constantly showing colder than average temperatures for us and the sings have been around for blocking to form for a while now...

Tom Cruises Left Nut

2 more tweets this morning

Interesting signs into early Dec with a potential stratospheric warming event



Coinciding with that is the continued sign for the vortex to potential split as well into early Dec -

BLIZZARD7

Okay the blocking signal eased off slightly for a couple of days but it is most definitley back today with incredible runs from the GFS 00Z and 06Z, ECM isnt looking bad either.

00Z at +174 hrs



WAA up western side of Greenland (essential for a sustained greeny high) Destruction of the polar vortex
And high presure building over scandi/svalbard at the same time as the jet undercutting the block.

This is what happens at the end of the run- way out in FI but the building blocks are only at +144hrs to +192hrs.



ECM isnt quite as good but the theme is still there-



GFS 06Z then comes out with this-

+144hrs



+168hrs



+192hrs



Perfect run with amazing Heights to our north- Freezing weather with snow would be the result here.

NAEFS supports this too-





While all of this is far from certain, the Northern blocking is starting to move towards the reliable time frame and is appearing on more and more runs. Watch this space...





Dan

ZX7R

Sioman keeling has a excellent weather forecast today on www.weatherweb.net he go's into great detail about how he see the cold developing at the end of the month,he starts to talk about the cold half way through todays video

Min

Joe Bastardi on twitter: IMO, Europe Dec look like blend of 09/10 above normal snow into france, germ...tweet was cut off at that point

dexter647

Iancar29

Its looking more certain now that high pressure ( of some degree) will build near greenland .



This will help open the gates to allow a NE Easterly flow establish then .



Met Office

As is usual, there are uncertainties in the forecast for this period. There are however, some signs of more settled conditions across much of the UK during the first part of December. So, although there are no strong indications of any particular weather type predominating, on balance, colder than average conditions are favoured, with an increased risk of frost and fog, as well as some wintry showers.

Updated: 1136 on Mon 19 Nov 2012


So for now... this is my reaction at this morning models...

Red Pepper

Jesus lads, I cant read any of these charts.

Are we going to have a load of snow and ice or not? In English please!

Speak Now

Red Pepper wrote: »

Jesus lads, I cant read any of these charts.

Are we going to have a load of snow and ice or not? In English please!

Way too early to tell.

gbee

Red Pepper wrote: »

Jesus lads, I cant read any of these charts.

Yes, get ready. Because of the nature of the systems involved, sudden but comparatively brief periods of cold including snow has already been indicated.

Essentially this pattern remains, the blocking feature so prevalent for last winter won't hold so well for the remainder of the season. Last winter we were under the threat of mini ice age scenario but that blocking gave us almost summer.

Winter has no signs of being as severe this year, but the colder fringes will almost certainly give us snow and cold.

Take the usual precautions but don't go mad, we will flip flop, a couple of days IMO at a time.

Musicman2000

Just reading MT'S update this morning and he said no sign of cold?? am I missing something?

whataboutnow

met office is hinting at it and so www.weatheronline.co.uk
have a read

Tom Cruises Left Nut

Musicman2000 wrote: »

Just reading MT'S update this morning and he said no sign of cold?? am I missing something?

I did notice that. Sure we will see what the 12z and 00z models do, he might change his mind !

Tom Cruises Left Nut

12z time

Sponge Bob

Iancar29 wrote: »

Its looking more certain now that high pressure ( of some degree) will build near greenland .



This will help open the gates to allow a NE Easterly flow establish then .

12z GFS developes the Blocking high even sooner.

Iancar29

Sponge Bob wrote: »

12z GFS developes the Blocking high even sooner.

Classic OMega block starting right there!!

Question will be though.. is it happening TOO early? ha

Just waiting now for the GEM to see if it also continues the trend..

Tom Cruises Left Nut

Excellent quote from Ian Ferguson, we should all remember this !

Too much panic...worry not!!
(NB: as a respected UKMO colleague just said to me about this, to put into perspective: "I just don't get why so many people get so fretful about the longer-range stuff showing in GFS and the like. It's a total waste of energy, as the underpinning science is still so way, way off affording any worthwhile reliability that detailed analysis is pointless and often results in an exhaustive over-analysis from what I see looking on forums..."

Birdnuts

A very tasty looking ECM this evening from 180 hrs out, with strong suggestion of a "beast from the East"!! - the big question though is whether there is any cold air availiable out to our East so early in the season

ninebeanrows

Birdnuts wrote: »

A very tasty looking ECM this evening from 180 hrs out, with strong suggestion of a "beast from the East"!! - the big question though is whether there is any cold air availiable out to our East so early in the season

Yes a bit disappointing with the synoptics projected, however if they stayed in place for any length of time, a cold pool would eventually reach us.

We may have to sit through a watery 3/4 day easterly, then perhaps see a retrogression to Greenland and an injection of cold airmass from the Arctic/Siberia.

If you look back at 2010 this also happened. The first attack from the east wasn't sharp, it took successive attempts before we got the full monty.

Tom Cruises Left Nut

The BOM wants in on the action and upper temps are much better

catch.23

Still borderline for snow apart from the north east though on that chart ^^^.

Eastcoastryan

I have been suprised how quiet it's been in here. The outlook is looking pretty positive.. No?

I realise that Europe isn't cold at the minute but I'm assuming there is time for that to change. If nothing else, I think it's positive that we are seeing the possibility of cold weather before Christmas again, that doesn't happen too often. Positive Thoughts Everyone!

t|nt|n wrote: »

The BOM wants in on the action and upper temps are much better

BEASTERLY

Very surprising to see so much consensus among the major models so far out! Especially given that it is a rare enough set up!

Wolfe_IRE

The models have been suggesting the following for the past few weeks .... colder but more settled end to November. This remains the case. Temps will be a degree or two below normal and it will be largely settled. What we need to look at now is if the blocking setup can lock into place and colder air can feed down from the arctic into scandinavia or western Russian and towards us. They are big ifs. Cold fans are only halfway there at best at present.

ninebeanrows

snip

derekon

British Weather Services (made up of ex UK Met Office folk) has issued the following weather advisory for the start of December........the word potential of course has to be highlighted.

http://www.britishweatherservices.co.uk/weather-advisory-issued-re-early-december-wintry-potential/

Anyone else getting a wee bit excited? :D

D

Shamrock841

derekon wrote: »

British Weather Services (made up of ex UK Met Office folk) has issued the following weather advisory for the start of December........the word potential of course has to be highlighted.

http://www.britishweatherservices.co.uk/weather-advisory-issued-re-early-december-wintry-potential/

Anyone else getting a wee bit excited? :D

D

Trying to stay calm and remember there is still a lot that can go right/wrong, would love to see a bit of the white stuff though!